Heteroatom Chemistry
Volume 2019 (2019), Article ID 1658417, 12 pages
https://doi.org/10.1155/2019/1658417

Research Article

Synthesis, Antimicrobial Properties, and Inhibition of Catalase Activity of 1,4-Naphtho- and Benzoquinone Derivatives Containing N-, S-, O-Substituted

Semih Kurban,¹ Nahide Gulsah Deniz,¹ Cigdem Sayil,¹ Mustafa Ozyurek,² Kubilay Guclu,³ Maryna Stasevych,⁴ Viktor Zvarych,⁴ Olena Komarovska-Porokhnyavet,⁴ and Volodymyr Novikov⁴

¹Division of Organic Chemistry, Department of Chemistry, Engineering Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
²Division of Analytical Chemistry, Department of Chemistry, Engineering Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
³Faculty of Arts and Sciences, Department of Chemistry, Aydın Adnan Menderes University, Aydın, Turkey
⁴Department of Technology of Biologically Active Substances, Pharmacy and Biotechnology, Lviv Polytechnic National University, Lviv, Ukraine

Correspondence should be addressed to Cigdem Sayil; sayil@istanbul.edu.tr

Received 3 October 2018; Accepted 10 December 2018; Published 2 January 2019

Academic Editor: Gianluigi Broggini

Copyright © 2019 Semih Kurban et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract.

A series of new 1,4-naphtho- and benzoquinone derivatives possessing N-, S-, O-substituted groups which has not been reported yet has been synthesized from 2,3-dichloro-1,4-naphthoquinone 1 and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 involving a Michael addition. In the synthesized compounds, antimicrobial activity at low concentrations against Escherichia coli B-906, Staphylococcus aureus 209-P, and Mycobacterium luteum B-917 bacteria and Candida tenuis VKM Y-70 and Aspergillus niger F-1119 fungi in comparison with controls was identified. 2-Chloro-3-((2-(piperidin-1-yl)ethyl)amino)naphthalene-1,4-dione 3g and 2,5-dichloro-3-ethoxy-6-((2,4,6-trifluorophenyl)amino)cyclohexa-2,5-diene-1,4-dione 17 were the most potent, with a minimum inhibitory concentration value of 15.6 μg/mL against test-culture M. luteum and S. aureus, respectively. Furthermore, in this work, a catalase activity of benzo- and naphthoquinone derivatives was examined for the first time. The catalase activity of benzo- and naphthoquinone derivatives was determined, showing that compound 3g had significant inhibition activity for catalase enzyme.

1. Introduction

Natural and synthetic quinonoid compounds are well-known substances which possess a variety of biological properties such as anticancer, antibacterial, or antimalarial drugs as well as fungicides [1]. The heterocyclic derivatives of 1,4-naphthoquinones have been identified that have potent biological activities towards viral [2], molluscicidal [3], malarial [4], leishmanial [5], cancer [6], and bacterial and fungal diseases [7] due to their redox potentials [8]. Some of these pharmacological effects have been attributed to the formation of DNA-damaging anion-radical intermediates formed by bioreduction of the quinone nucleus. Quinones are known to inhibit electron transport involved in photosynthesis and mitochondrial respiration. Quinone-based fungicides are classified as “organic fungicides” and are known multisite inhibitors. This may be advantageous in the prevention of resistance development in fungal pathogens. Similarly, quinone-based natural herbicides were also described with multisite inhibitors.

As a part of a program directed towards the design and synthesis of N-, S-, O-substituted quinones as potential antibacterial, antifungal, and anticancer agents, we have reported the synthesis and antimicrobial as well as anticancer activities of N-, S-, O-substituted quinones [6, 9, 10]. This paper describes the synthesis, characterization, and discovering promising pharmacologically active compounds. In this work, a catalase activity of benzo- and naphthoquinone derivatives was examined for the first time. The catalase enzyme plays an important role in removing toxic H₂O₂ from the cells. For this purpose, the activities of the cells of this enzyme decompose H₂O₂ generated as a result of the cell activities H₂O and O₂ before dispersion into the body tissues. The catalase enzyme also exhibits peroxidic activity on compounds (i.e., formaldehyde, phenols, formic acid, and alcohols). In this reaction, low molecular weight alcohols serve as an electron donor. In addition to having peroxidase activity, this enzyme can use one molecule of H₂O₂ as an electron donor and the other as an oxidant [11, 12].

Consequently, the synthesis of new active derivatives with potential applications in this area and prepared by simple chemical procedures should be of increasing interest. Here we described the synthesis, characterization, antimicrobial activity, and inhibition of catalase of 1,4-naphtho- and benzoquinone derivatives. Their structures of synthesized compounds were characterized by using elemental analysis, FT-IR, ¹H NMR, ¹³C NMR, MS, and UV-Vis spectroscopy.

2. Experimental

2.1. Material and Methods

Infrared (FT-IR) spectra were recorded for liquids as film and for solids as KBr discs on a Perkin Elmer Precisely Spectrum One FTIR spectrometry. Microanalyses were carried out with a Thermo Finnigan Flash EA 1112 Elemental analyser. Mass spectra were obtained on a Thermo Finnigan LCQ Advantage MAX LC/MS/MS spectrometer according to either APCI or ESI techniques. ¹H NMR and ¹³C NMR spectra were recorded on Bruker Avance III 500 MHz, Chemical shifts δ (ppm) were reported relative to tetramethylsilane (TMS) with the solvent resonance employed as the internal standard. ¹H NMR and ¹³C NMR spectra in CDCl₃ refer to the solvent signal center at δ = 7.26 and δ = 77.0 ppm, respectively. Moisture was excluded from the glass apparatus using CaCl₂ drying tubes. Spectrophotometric catalase enzyme activity measurements of synthesized compounds were performed by using a Perkin Elmer Lambda 35 UV-Vis spectrophotometer using a pair of matched quartz cuvettes of 1 cm thickness.

The following chemicals were supplied from the corresponding sources: sodium carbonate, sodium sulfate, aniline, ethanethiol, 2,3-diaminopyridine, 4-fluorobenzylamine, 2-(piperidin-1-yl)ethan-1-amine, 2,4,6-trifluoroaniline, 4-fluorothiophenol, 2,3-difluoroaniline, and 1,3-dimethylbutylamine from Merck Chemicals (Darmstadt, Germany); acetone, absolute ethanol, and neocuproine (Nc) from Sigma-Aldrich Chemicals (Steinheim, Germany); 2,3-dichloro-1,4-naphthoquinone (Fluka).

2.2. Antibacterial and Antifungal Evaluations [13, 14]

Tested microorganisms included the following: bacteria Escherichia coli B-906, Staphylococcus aureus 209-P, and Mycobacterium luteum B-917 and fungi Candida tenuis VKM Y-70 and Aspergillus niger F-1119. The antimicrobial activity of compounds was evaluated by diffusion in peptone on a nutrient medium (meat-extract agar for bacteria and wort agar for fungi). The microbial loading was 10⁹ cells (spores)/1 mL. The required incubation periods were 24 h at 35°C for bacteria and 48–72 h at 28–30°C for fungi. The results were recorded by measuring the zones surrounding the disk. The control disk contained vancomycin (for bacteria) or nystatin (for fungi) as a standard. Testing was performed in a flat-bottomed 96-well tissue culture plate. The tested compounds were dissolved in DMSO applying the necessary concentration. The exact volume of the solution of compounds is brought into a nutrient medium. The bacteria and fungi were inoculated in a nutrient medium (meat-extract agar for bacteria and wort agar for fungi). The duration of incubation was 24–72 h at 37°C for bacteria and 30°C for fungi. The results were estimated according to the degree of the growth inhibition.

2.3. Catalase Enzyme Inhibition Activity of Quinone Derivatives

Catalase activity was determined by the rate of H₂O₂ decomposition, measured spectrophotometrically at 450 nm using the method described by Bekdeser et al. [15]. The reaction mixtures contained 1.0 mM H₂O₂, 3.691 U catalase solution, and 1.0 mM synthesized compound. This mixture (total volume 2.6 mL) was then incubated at 25°C. After 30 min incubation period, the optical CUPRAC sensor was taken out and immersed in a test tube consisted of 2.0 mL of the incubation reaction mixture + 6.2 mL of EtOH. After 30 min agitation, the colored membrane was taken out and its absorbance was recorded at 450 nm and activities were expressed in U .

2.4. General Procedure for the Synthesis of N-, N,N- N,O- N,S-, and S,S- Substituted Naphtho- and Benzoquinone Compounds 3a, 3c, 3d, 3f, 3g, 4e, 6b, 7a, 17-25

Sodium carbonate was dissolved in ethanol (60 mL), and equimolar amounts of 2,3-dichloro-1,4-naphthoquinone 1 and amines or thiols were added slowly. The mixture was heated between 20-45°C and it was stirred in a single reaction vessel between 2 and 11 h. Similarly, sodium carbonate was dissolved in ethanol (50 mL), and equimolar amounts of 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 and amines were added slowly. Without heating, the mixture was stirred in a single reaction vessel between 3-6 h. The color of the solution quickly changed (from yellow to red color), and the extent of the reaction was monitored by TLC. Chloroform (30 mL) was added to the reaction mixture. The organic layer was separated, washed with water (4 × 30 mL), and dried with Na₂SO₄. After the solvent was evaporated, the residue was purified by column chromatography on silica gel.

2.5. 2-Phenylamino-3-chloro-naphthalene-1,4-dione (3a) [16, 17]

Compound 3a was synthesized from aniline 2a (0.4 ml, 4.404 mmol) and 2,3-dichloro-1,4-naphthoquinone 1 (1 g, 4.404 mmol) according to the general method. Yield: 94.7%. Red crystal. M.p.: 215-216°C. (1PET:1CHCl₃): 0.44. FT-IR (KBr): υ (cm⁻¹) = 3065, 2918 (C-H.), 1673 (C=O), 1588, 1537 (C=C), 3238 (N-H).

2.6. 2-Chloro-3-((2,5-difluorobenzyl)amino)naphthalene-1,4-dione (3c)

Compound 3c was synthesized from (2,5-difluorophenyl) methanamine 2c (0.308 ml, 2.634 mmol) and 2,3-dichloro-1,4-naphthoquinone 1 (0.6 g, 2.634 mmol) according to the general method. Yield: 77.9%. Orange crystal. [PET/CHCl₃(5:2)]: 0.52. M.p.: 123–125°C. FT-IR (KBr) (cm⁻¹): 3276 (N-H), 3019 (C-), 2925, 2851 (C-), 1676 (C=O), 1576 (C=C). ¹H NMR (499.74 MHz, CDCl₃) δ (ppm) = 5.00 (d, 2H, J 6.68 Hz, -NH-CH₂), 6.21 (bs, 1H, NH), 6.88-7.00 (m, 3H, C), 7.55-7.66 (tt, 2H, J 7.54, 1.46 Hz, C), 7.96-8.08 (dd, 2H, J 7.72, 1.46 Hz, C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 155.6, 157.8 (-F-), 115.6, 116.7, 116.9 (C), 129.8 (), 143.7 (-NH-), 115.8 (-Cl-), 126.9,128.8, 130.9, 132.4 (C), 132.7, 135.0 (), 177.1, 180.2 (C=O). MS [+ESI] = m/z 334.1 [M+H]⁺, Anal. Calc. for C₁₇H₁₀ClF₂NO₂ (333.04): C 61.18, H 3.02, N 4.20. Found: C 61.41, H 3.34, N 4.14%. UV-vis [CHCl₃, (nm)()]: 210(2.2), 274(2.4), 336(1.4), 559(1.5).

2.7. 2-Chloro-3-((2,3-difluorophenyl)amino)naphthalene-1,4-dione (3d)

Compound 3d was synthesized from 2,3-difluoroaniline 2d (0.287 g, 2.212 mmol) and 2,3-dichloro-1,4-naphthoquinone 1 (0.5 g, 2.212 mmol) according to the general method. Yield: 71.1%. Orange crystal. [PET/CHCl₃(5:2)]: 0.51. M.p.: 106–109°C. FT-IR (KBr) (cm⁻¹): 3019 (C-), 2925 (C-), 1650 (C=O), 1520 (C=C), 3340 (N-H). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 7.33 (bs, 1H, NH), 6.81-6.03, 7.45-7.48 (m, 3H, C), 7.63-7.75 (tt, 2H, J 7.54, 1.56 Hz, C), 8.04-8.14 (dd, 2H, J 7.71, 1.56 Hz, C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 129.8 (-NH-), 146.2, 149.7 (-F-), 114.5, 121.4, 123.0 (C), 135.1 (-NH-), 116.6 (-Cl-), 127.1, 127.2, 130.9, 141.5 (C), 133.2, 132.2 (), 177.5, 179.9 (C=O). MS [-ESI] = 318.2 [M-H]⁻, Anal. Calc. for C₁₆H₈ClF₂NO₂ (319.02): C 60.11, H 2.52, N 4.38. Found: C 60.12, H 2.50, N 4.40%. UV-vis [CHCl₃, (nm)()]: 223(3.9), 274(4.0), 348(3.2), 453(3.1).

2.8. 2-Chloro-3-((4-methylpentan-2-yl)amino)naphthalene-1,4-dione (3f)

Compound 3f was synthesized from 4-methylpentan-2-amine 2f (0.433 ml, 3.083 mmol) and 2,3-dichloro-1,4-naphthoquinone 1 (0.7 g, 3.083 mmol) according to the general method. Yield: 89.6%. Orange crystal. [PET/CHCl₃ (2:1)]: 0.48. M.p.: 98–99°C. FT-IR (KBr) (cm⁻¹): 3015 (C-), 2959, 2928 (C-), 1643 (C=O), 1600, 1573 (C=C), 3322 (N-H). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 0.85 (d, 3H, J 7.52 Hz, -C), 0.87 (d, 3H, J 6.62 Hz, -C), 1.20 (d, 3H, J 6.37 Hz, -C), 4.65-4.75, 1.56-1.66 (m, 2H, -CH), 1.44-1.51, 1.26-1.34 (m, 2H, -CH₂), 5.81 (bs, 1H, NH), 7.52-7.66 (tt, 2H, J 7.54, 1.56 Hz, C), 7.94-8.06 (dd, 2H, J 7.71, 1.56 Hz, C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 22.4, 22.6, 22.9 (-CH₃), 25.2, 48.2 (-CH-), 47.1 (-CH₂-), 143.5 (-NH-), 126.9 (-Cl-), 128.8, 129.8, 130.9, 132.2 (C), 132.5, 135.0 (), 176.4, 182.1 (C=O). MS [+ESI] = m/z 292.1 [M+H]⁺, Anal. Calc. for C₁₆H₁₈ClNO₂ (291.78) C 65.86, H 6.22, N 4.80. Found: C 65.82, H 6.24, N 4.81%. UV-vis [CHCl₃, (nm)()]: 238(3.2), 277(3.4), 343(3.4), 469(2.6).

2.9. 2-Chloro-3-((2-(piperidin-1-yl)ethyl)amino)naphthalene-1,4-dione (3g) [18]

Compound 3g was synthesized from 2-(piperidin-1-yl) ethan-1-amine 2 g (0.317 ml, 2.202 mmol) and 2,3-dichloro-1,4-naphthoquinone 1 (0.5 g, 2.202 mmol) according to the general method. Yield: 80.9%. Red crystal. [PET/CHCl₃ (3:1)]: 0.48. M.p.: 108–110°C. FT- IR (KBr) (cm⁻¹): 3016 (C-), 2938, 2853 (C-), 1677 (C=O), 1603, 1573 (C=C), 3355 (N-H). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 1.36-1.58 (m, 6H, -CH2circle-), 2.34-2.42 (m, 4H, -N-C), 2.53 (t, 2H, J 5.96 Hz, -CH₂-N-), 3.80 (t, 2H, J 5.88 Hz, -NH-CH₂), 6.98 (bs, 1H, NH), 7.48-7.63 (tt, 2H, J 7.55, 1.46 Hz, C), 7.86-8.02 (dd, 2H, J 7.25, 1.46 Hz, C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 24.4, 26.1 (C), 41.2 (-NH-CH₂), 56.8 (-N-CH₂), 53.8 (-N-C), 144.8 (-NH-), 110.9 (-Cl-), 126.5, 129.8, 132.2 (C), 132.7, 134.6 (), 176.2, 180.4 (C=O). MS [+ESI] = m/z 319.2 [M+H]⁺, Anal. Calc. for C₁₇H₁₉ClN₂O₂ (318.11): C 64.05, H 6.01, N 8.79. Found: C 63.97, H 6.26, N 8.69%. UV-vis [CHCl₃, (nm)()]: 211(2.8), 277(3.4), 339(2.3), 473(2.5).

2.10. 2-Ethoxy-3-((2-methyl-4-oxo-4H-chromen-7-yl)amino)naphthalene-1,4-dione (4e)

Compound 4e was synthesized from 7-amino-2-methyl-4H-chromen-4-one 2e (0.385 g, 2.202 mmol) and 2,3-dichloro-1,4-naphthoquinone 1 (0.5 g, 2.202 mmol) according to the general method. Yield: 54.9%. Red crystal. [PET/CHCl₃(5:2)]: 0.58. M.p.: 140–142°C. FT-IR (KBr) (cm⁻¹): 2971 (C-), 2926, 2850 (C-), 1682 (C=O), 1599, 1520 (C=C), 3306 (N-H). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 0.83 (t, 3H, J= 7.52 Hz, C), 1.17 (bs, 3H, CH₃), 4.01-4.04 (q, 2H, J 7.06 Hz, O-C), 5.65 (bs, 1H, CH₂), 6.08 (bs, 1H, O-CH), 6.28-6.29 (d, 1H, J 7.06 Hz, C), 7.44-7.46 (d, 1H, J 7.06 Hz, C), 7.54-7.66 (tt, 2H, J 7.53, 1.46 Hz, C), 5.96 (bs, 1H, NH), 7.94-8.09 (dd, 2H, J 7.7, 1.46 Hz, C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 11.0 (-C), 14.1 (-C), 68.2 (-O-C), 109.9, 112.2, 119.4, 127.0 (C), 120.5 (), 167.3 (CH₃-), 162.0 (C-), 160.8 (NH-), 173.8 (C=), 134.9 (O-), 115.5 (-NH-), 128.0, 128.4, 130.8, 130.9 (C), 132.5 132.6 (), 176.9, 180.5 (C=O). MS [-ESI] = m/z 372.9 [M-2H]⁻, Anal. Calc. for C₂₂H₁₇NO₅ (375.11): C 70.39, H 4.56, N 3.73. Found: C 70.24, H 4.45, N 3.80%. UV-vis [CHCl₃, (nm)()]: 243(3.0), 276(3.1), 344(2.3), 468(2.1).

2.11. 2,3-Bis((4-fluorophenyl)thio)naphthalene-1,4-dione (6b) [19]

Compound 6b was synthesized from 4-fluorobenzenethiol 5b (0.375 ml, 3.523 mmol) and 2,3-dichloro-1,4-naphthoquinone 1 (0.4 g, 1.761 mmol) according to the general method. Yield: 79.1%. Orange crystal. [PET/CHCl₃ (2:1)]: 0.55. M.p.: 175–177°C. FT-IR (KBr) (cm⁻¹): 3008 (C-), 2923, 2853 (C-H), 1665 (C=O), 1586 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 7.41-7.46 ppm (m, 4H, C), 7.01-7.06 (m, 4H, C), 7.68-7.72 (m, 2H, C), 7.96-8.00 (m, 2H, C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 128.4 (-S-), 161.6-163.6 (-F-), 116.3-116.5, 133.7-133.9 (C), 132.6 (-S-), 127.2, 133.6 (C), 148.9 (), 178.7, 178.7 (C=O). MS [+ESI] = m/z 411 [M+H]⁺, Anal. Calc. for C₂₂H₁₂F₂O₂S₂ (410.02): C 64.38, H 2.95, S 15.62. Found: C 64.38, H 2.94, S 15.62%. UV-vis [CHCl₃, (nm)()]: 211(2.6), 253(2.5), 342(1.9), 458(1.7).

2.12. 2-(Ethylthio)-3-(phenylamino)naphthalene-1,4-dione (7a) [20]

Compound 7a was synthesized from ethanethiol 5a (0.110 ml, 1.762 mmol) and 2-chloro-3-(phenylamino) naphthalene-1,4-dione 3a (0.5 g, 1.762 mmol) according to the general method. Yield: 91.5%. Red crystal. [PET/CHCl₃ (5:2)]: 0.57 M.p.: 92–94°C. FT-IR (KBr) (cm⁻¹): 3008 (C-), 2923, 2853 (C-H), 1665 (C=O), 1586 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 0.96 (t, 3H, J 7.38 Hz, CH₃), 2.56 (q, 2H, J 7.39 Hz, S-CH₂), 6.97 (d, 2H, J 7.74 Hz, C), 7.08 (t, 1H, J 7.44 Hz, C), 7.27 (t, 2H, J 7.56 Hz, C), 7.58-7.68 (tt, 2H, J 7.53, 1.46 Hz, C), 7.76 (bs, 1H, NH), 8.00-8.09 (dd, 2H, J 7.7, 1.46 Hz, C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 14.5 (-CH₃), 28.0 (SCH₂-), 122.5, 124.7, 126.6 (C), 124.5 (S-), 126.8 (-NH-), 129.4, 130.8, 132.8 (C), 134.6, 138.5 (), 145.0 (NH-C), 180.5, 181.1 (C=O). MS [-ESI] = m/z 308.01 [M-H]⁻, Anal. Calc. for C₁₈H₁₅NO₂S (309.08): C 69.88, H 4.69, N 4.53. Found: C 70.04, H 4.88, N 4.57%. UV-vis [CHCl₃, (nm)()]: 210(2.4), 283(2.6), 382(1.9), 511(1.7).

2.13. 2-Chloro-3-(o-tolylamino)naphthalene-1,4-dione (9) [16, 21]

Compound 9 was synthesized from o-toluidine 8 (0.235 g, 2.202 mmol) and 2,3-dichloro-1,4-naphthoquinone 1 (0.5 g, 2.202 mmol) according to the general method. Yield: 72.7%. Red crystal. [PET/CHCl₃ (1:1)]: 0.41. M.p.: 162–163°C. FT-IR (KBr) (cm⁻¹): 3060, 2946 (C-H.), 1672 (C=O), 1595, 1573 (C=C), 3244 (N-H).

2.14. General Procedure for the Synthesis of N,N-Substituted Naphthoquinone Compounds (1-Methylbenzo[b]phenazine-6,11-dione 11 and 2-Methylbenzo[b]phenazine-6,11-dione 14 [22])

Mono substituted naphthoquinone derivatives 9 [21] and 13 (1 mol) were dissolved in DMF (100 mL) and sodium azide (NaN₃) (2 mol) dissolved in 10 ml of water was slowly added. The reaction was heated to reflux with stirring. The color of the solution quickly changed (from yellow to red color), and the extent of the reaction was monitored by TLC. Chloroform (40 mL) was added to the reaction mixture. The organic layer was separated, washed with water (4 × 50 mL), and dried with Na₂SO₄. After the solvent was evaporated, the residue was purified by column chromatography on silica gel.

2.15. 1-Methylbenzo[b]phenazine-6,11-dione (11)

Compound 11 was synthesized from sodium azide 10 (0.131 g, 2.015 mmol) and 2-chloro-3-(o-tolylamino) naphthalene-1,4-dione 9 [21] (0.3 g, 1.007 mmol) according to the general method. Yield: 75.7%. Dark blue crystal. [PET/CHCl₃(1:1)]: 0.53. M.p.: 139–141°C. FT-IR (KBr)(cm⁻¹): 3019 (C-), 2926, 2860 (C-H), 1624 (C=O), 1524 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 2.30 (bs, 3H, -C), 7.13 (d, 1H, J 7.81 Hz, -C-), 7.08 (t, 1H, J 7.83 Hz, -C-), 6.37 (d, 1H, J 7.88 Hz, -C-), 7.53-7.61 (m, 2H, C), 7.95-7.99 (m, 2H, C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 18.1 (C) 114.1, 120.7, 128.0 (-C), 132.6 (CH₃-), 137.7, 139.0 (-N=), 131.7, 133.7 (-N-), 121.8, 126.0, 126.2 (C), 130.6, 130.7 (), 180.7, 180.8 C=O). MS [+ESI] = 276.1 [M+2H]⁺. Anal. Calc. for C₁₇H₁₀N₂O₂ (274.07): C 74.44, H 3.68, N 10.21. Found: C 74.63, H 3.45, N 10.18%. UV-vis [CHCl₃, (nm)()]: 241(2.5), 298(2.6), 429(1.2), 544(1.6).

2.16. 2-Chloro-3-(m-tolylamino)naphthalene-1,4-dione (13) [16, 23]

Compound 13 was synthesized from m-toluidine 12 (0.188 g, 1.761 mmol) and 2,3-dichloro-1,4-naphthoquinone 1 (0.4 g, 1.761 mmol) according to the general method. Yield: 75.3%. Red crystal. [PET/CHCl₃ (1:1)]: 0.41. M.p.: 177–179°C. FT-IR (KBr) (cm⁻¹): 3045, 2915 (C-H.), 1675 (C=O), 1593, 1560 (C=C), 3237 (N-H).

2.17. 2-Methylbenzo[b]phenazine-6,11-dione (14) [22]

Compound 14 was synthesized from sodium azide 10 (0.087 g, 1.344 mmol) and 2-chloro-3-(m-tolylamino) naphthalene-1,4-dione 13 (0.2 g, 0.672 mmol) according to the general method. Yield: 73.0%. Dark navy blue crystal. [PET/CHCl₃)(2:1)]: 0.50. M.p.: 193–195°C. IR (KBr) (cm⁻¹): 3019 (C-), 2926, 2850 (C-H), 1616 (C=O), 1577, 1522 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 2.35 (bs, 3H, -C), 7.18-7.22 (t, 1H, J 7.81 Hz, -C-), 6.78-6.82 (d, 1H, J 7.49 Hz, -C-), 6.57-6.60 (d, 1H, J 7.52 Hz, -C-), 7.63-7.69 (m, 2H, C), 8.04-8.08 (m, 2H, C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 21.5 (C) 119.0, 120.3, 122.4 (-C), 132.8 (CH₃-), 139.1, 139.7 (-N=), 131.8, 133.7 (-N-), 115.5, 126.0, 126.2 (C), 128.9, 129.5 (), 180.7, 180.8 (C=O). MS [+ESI] = m/z 276.0 [M+2H]⁺, Anal. Calc. for C₁₇H₁₀N₂O₂ (274.07): C 74.44, H 3.68, N 10.21. Found: C 74.49, H 3.34, N 10.19%. UV-vis [CHCl₃, (nm)()]: 212(2.2), 241(2.1), 298(2.2), 539(1.2).

2.18. 2,5-Dichloro-3-ethoxy-6-((2,4,6-trifluorophenyl)amino)cyclohexa-2,5-diene-1,4-dione (17)

Compound 17 was synthesized from 2,4,6-trifluoroaniline 16 (0.597 g, 2.440 mmol) and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 (1.0 g, 4.067 mmol) according to the general method. Yield: 28.3%. Red crystal. [PET/CHCl₃(3:1)]: 0.51. M.p.: 131–132°C. FT-IR (KBr) (cm⁻¹): 3341 (N-H), 3018, 2956 (C-), 2923, 2851 (C-H), 1712, 1640 (C=O), 1588-1522 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 0.80 (t, 3H, J 7.08 Hz, -CH3ethoxy), 4.33 (q, 2H, J 7.05 Hz, -O-C), 6.52 (bs, 1H, -NH-), 6.63-6.67 (m, 6H, -C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 100.5, 100.5 (-C), 150.3-152.1, 152.1-154.0 (C-F-), 124.3 (NH-), 14.2 (-C), 68.1 (-C), 146.9 (-NH-), 114.2, 118.9 (C-Cl-), 158.0 (C-O-), 164.5, 166.1 (C=O). MS [-ESI] = m/z 364.0 [M]⁻, Anal. Calc. for C₁₄H₈Cl₂F₃NO₃ (364.98): C 45.93, H 2.20, N 3.83. Found: C 45.98, H 2.19, N 3.94%. UV-vis [CHCl₃, (nm)()]: 225(2.2), 301(2.7), 377(1.4), 462(1.2).

2.19. 2,5-Dichloro-3,6-bis((2,4,6-trifluorophenyl)amino)cyclohexa-2,5-diene-1,4-dione (18)

Compound 18 was synthesized from 2,4,6-trifluoroaniline 16 (0.597 g, 2.440 mmol) and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 (1.0 g, 4.067 mmol) according to the general method. Yield: 39.2%. Light yellow crystal. [PET/CHCl₃(3:1)]: 0.55. M.p.: 154–156°C. FT-IR (KBr) (cm⁻¹): 3380 (N-H), 3019, 2961 (C-), 2927, 2858 (C-H), 1716 (C=O), 1519 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 4.26 (bs, 2H, -NH-), 7.93-7.98 (m, 4H, -C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 101.2 (-C), 153.9-155.8, 155.8-157.3 (C-F-), 124.3 (NH- ), 141.0 (-NH-), 111.3 (C-Cl-), 166.0 (C=O). MS [-ESI] = m/z 464.9 [M-H]⁻, Anal. Calc. for C₁₈H₆Cl₂F₆N₂O₂ (465.97 g/mol): C 46.28, H 1.29, N 6.00. Found: C 46.40, H 1.25, N 6.09%. UV-vis [CHCl₃, (nm)()]: 247(3.1), 292(3.0), 377(2.7), 462(2.4).

2.20. 2-Chloro-3,6-diethoxy-5-((4-fluorobenzyl)amino)cyclohexa-2,5-diene-1,4-dione (19)

Compound 19 was synthesized from (4-fluorophenyl) methanamine 2h (0.275 ml, 2.440 mmol) and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 (0.6 g, 2.440 mmol) according to the general method. Yield: 21.1%. Dark red crystal. [(PET/CHCl₃(5:2)]: 0.58. M.p.: 60–62°C. FT-IR (KBr) (cm⁻¹): 3345 (N-H), 3001 (C-), 2982, 2929 (C-H), 1682 (C=O), 1570 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 1.37 (t, 3H, J 7.06 Hz, -CH3ethoxy), 1.36 (t, 3H, J 7.06 Hz, -CH3ethoxy), 4.12-4.52 (m, 4H, -O-C), 1.71 (d, 2H, J 4.97 Hz, -NH-C), 5.66 (bs, 1H, -NH-), 6.13-6.35 (m, 4H, -C).¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 171.5-173.3 (-C-), 140.5, 138.6, 110.8, 111.4 (-C), 144.3 (-), 29.5 (-N-CH₂-) 70.3, 71.5, 15.9, 20.7 (-C), (-C), 125.8 (--NH-) 102.0 (C-Cl-), 143.9, 154.4 (C-O-), 171.7, 172.8 (C=O). MS [-ESI] = m/z 352.3 [M-H]⁻, Anal. Calc. for C₁₇H₁₇ClFNO₄ (353.08): C 57.72, H 4.84, N 3.96. Found: C 57.89, H 4.58, N 3.98%. UV-vis [CHCl₃, (nm)()]: 217(1.7), 241(1.8), 298(2.1), 430(0.3).

2.21. 2-Chloro-5-ethoxy-3,6-bis((4-fluorobenzyl)amino)cyclohexa-2,5-diene-1,4-dione (20)

Compound 20 was synthesized from (4-fluorophenyl) methanamine 2h (0.275 ml, 2.440 mmol) and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 (0.6 g, 2.440 mmol) according to the general method. Yield: 37.3%. Orange crystal. [PET/CHCl₃(5:2)]: 0.55. M.p.: 82–84°C. FT-IR (KBr) (cm⁻¹): 3300 (N-H), 3009, 2961 (C-), 2930, 2874 (C-H), 1682 (C=O), 1624, 1579 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 1.35 (t, 3H, J 7.05 Hz, -CH3ethoxy), 4.40 (q, 2H, J 7.05 Hz, -O-C), 4.50 (d, 4H,, J 8.09 Hz, -NH-C), 5.81, 6.78 (bs, 2H, -NH-), 7.08-7.65 (m, 8H, -C).¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 174.2-176.3 (-C-), 123.4, 125.9, 128.9, 131.0 (-C), 132.4 (-), 29.0, 30.3 (-N-CH₂-), 71.3, 15.9 (-C) ve (-C), 154.1, 153.1 (--NH-), 105.9 (C-Cl-), 129.6 (C-O-), 171.5, 175.3 (C=O). MS [+ESI] = m/z 433.3 [M+H]⁺, Anal. Calc. for C₂₂H₁₉ClF₂N₂O₃ (432.11): C 61.05, H 4.42, N 6.47. Found: C 61.14, H 4.76, N 6.51%. UV-vis [CHCl₃, (nm)()]: 205(1.9), 240(1.7), 303(2.1), 430(0.5).

2.22. 2-Chloro-5,6-diethoxy-3-((4-fluorobenzyl)amino)cyclohexa-2,5-diene-1,4-dione (21)

Compound 21 was synthesized from (4-fluorophenyl) methanamine 2h (0.275 ml, 2.440 mmol) and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 (0.6 g, 2.440 mmol) according to the general method. Yield: 18.2%. Dark red crystal. [PET/CHCl₃(5:2)]: 0.51. M.p.: 104–106°C. FT-IR (KBr) (cm⁻¹): 3242 (N-H), 3003-2957 (C-), 2926, 2855 (CH), 1690 (C=O), 1579-1519 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 1.35 (t, 3H, J 7.05 Hz, -CH3ethoxy), 1.37 (t, 3H, J 7.05 Hz, -CH3ethoxy), 4.19-4.53 (q, 4H, J 7.05 Hz, -O-C), 1.68 (d, 2H, J 4.97 Hz, -NH-C), 5.49 (bs, 1H, -NH-), 6.15-6.30 (m, 4H, -C). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 163.6-161.7 (-C-), 129.4, 129.6, 116.0, 116.2 (-C), 132.9 (-), 29.8 (-N-CH₂-), 68.2, 71.6, 11.0, 14.1 (-C) ve (-C), 143.5 (--NH-), 128.7 (C-Cl-), 135.9, 142.0 (C-O-), 169.9, 174.2 (C=O). MS [-ESI] = m/z 352.33 [M-H]⁻, Anal. Calc. for C₁₇H₁₇ClFNO₄ (353.08): C 57.72, H 4.84, N 3.96. Found: C 57.92, H 4.68, N 3.98%. UV-vis [CHCl₃, (nm)()]: 206(2.0), 241(2.1), 298(2.4), 430(0.5).

2.23. 2,5-Diethoxy-3,6-bis((4-fluorobenzyl)amino)cyclohexa-2,5-diene-1,4-dione (22)

Compound 22 was synthesized from (4-fluorophenyl)methanamine 2h (0.275 ml, 2.440 mmol) and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 (0.6 g, 2.440 mmol) according to the general method. Yield: 16,4%. Pale pink crystal. [PET/CHCl₃ (5:2)]: 0.48. M.p.: 226–228°C. FT-IR (KBr) (cm⁻¹): 3244 (N-H), 3019 (C-), 2929, 2850 (CH), 1663 (C=O), 1586 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 0.84 (t, 6H, J 7.46 Hz, -CH3ethoxy), 4.10-4.18 (m, 4H, -O-C), 4.88 (d, 2H, J 6.18 Hz, -NH-C), 6.00 (bs, 2H, -NH-), 6.98-7.64 (m, 8H, -C).¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 161.2, 163.0 (-C-), 130.8, 131.0, 112.9,113.1 (-C), 140.2 (-), 32.0 (-N-CH₂-), 71.4, 15.9 (-C) ve (-C), 122.4 (--NH-), 132.7 (C-O-), 175.1 (C=O). MS [+ESI] = m/z 445.0 [M+2H]⁺, Anal. Calc. For C₂₄H₂₄F₂N₂O₄ (443.17): C 65.15, H 5.47, N 6.33. Found: C 65.08, H 5.80, N 6.27%. UV-vis [CHCl₃, (nm)()]: 219(3.7), 245(3.8), 462(2.4), 557(2.6).

2.24. 2,5-Dichloro-3-((2,5-difluorobenzyl)amino)-6-ethoxycyclohexa-2,5-diene-1,4-dione (23)

Compound 23 was synthesized from (2,5-difluorophenyl)methanamine 2c (0.290 g, 2.033 mmol) and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 (0.5 g, 2.033 mmol) according to the general method. Yield: 52.4%. Dark purple crystal. [PET/CHCl₃(3:1)]: 0.47. M.p.: 73–74°C. FT-IR (KBr) (cm⁻¹): 3346 (N-H), 3020 (C-), 2927, 2856 (CH), 1667 (C=O), 1522 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 1.36 (t, 3H, J 7.05 Hz, -CH3ethoxy), 4.62 (q, 2H, J 7.03 Hz, -O-C), 4.95 (d, 2H, J 6.72 Hz, -NH-CH₂), 6.27 (bs, 1H, -NH-), 6.85-7.15 (m, 3H, -C).¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 116.4, 117.5, 120.3 (-C), 126.5 (-), 155.5-157.4, 157.8-159.7 (C-F-), 42.4 (-CH₂-NH-), 16.1 (-CH3ethoxy), 68.0 (-C), 156.4 (-NH-), 115.8, 119.4 (C-Cl-), 162.2 (C-O-), 175.9, 173.8 (C=O). MS [-ESI] = m/z 360.0 [M-H]⁻, Anal. Calc. for C₁₅H₁₁Cl₂F₂NO₃ (361.01): C 49.75, H 3.06, N 3.87. Found: C 49.96, H 3.00, N 3.91. UV-vis [CHCl₃, (nm)()]: 219(2.2), 241(2.4), 311(2.3), 492(1.2).

2.25. 2,3,5-Trichloro-6-((2-(piperidin-1-yl)ethyl)amino)cyclohexa-2,5-diene-1,4-dione (24)

Compound 24 was synthesized from 2-(piperidin-1-yl) ethan-1-amine 2 g (0.208 g, 1.626 mmol) and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 (0.4 g, 1.626 mmol) according to the general method. Yield: 33.3%. Dark red crystal. [PET/CHCl₃ (3:1)]: 0.51. M.p.: 60–62°C. FT-IR (KBr) (cm⁻¹): 3332 (N-H), 3019, 2932 (CH), 1639 (C=O), 1522 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 1.22-1.32, 2.44-2.76 (m, 10H, --CH₂), 3.15 (t, 2H, J 5.67 Hz, -C-N-), 4.17-4.20 (m, 2H, -NH-CH₂), 8.03 (bs, 1H, -NH). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 20.0, 23.8, 23.9, 54.1, 54.2 (-CH2circle), 44.0, 56.1 (-N-CH₂-CH₂-N-), 148.4 (-C-NH-), 120.0, 140.1, 142.7 (C-Cl-), 162.3, 174.9 (C=O). MS [+ESI] = m/z 339.4 [M+2H]⁺, Anal. Calc. for C₁₃H₁₅Cl₃N₂O₂ (337.63): C 46.25, H 4.48, N 8.30. Found: C 46.22, H 4.72, N 8.25%. UV-vis [CHCl₃, (nm)()]: 217(2.8), 293(1.9), 354(2.0), 587(1.9).

2.26. 2-Chloro-5-ethoxy-3,6-bis((2-(piperidin-1-yl)ethyl)amino)cyclohexa-2,5-diene-1,4-dione (25)

Compound 25 was synthesized from 2-(piperidin-1-yl)ethan-1-amine 2 g (0.208 g, 1.626 mmol) and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 (0.4 g, 1.626 mmol) according to the general method. Yield: 36.3%. Dark red crystal. [PET/CHCl₃ (3:1)]: 0.54. M.p.: 241–243°C. FT-IR (KBr) (cm⁻¹): 3295 (N-H), 3019, 2923 (CH), 1678 (C=O), 1570 (C=C). ¹H NMR (499.74 MHz, CDCl₃) (ppm) = 0.81 (t, 3H, J 7.03 Hz,-CH3ethoxy), 1.15-1.55, 2.10-2.24 (m, 20H, -C-N-), 2.26-2.28, 2.38-2.41 (m, 4H, --CH₂), 4.13-4.23 (m, 4H, -NH-CH₂), 4.50 (q, 2H, J= 5.35 Hz, O-CH2ethoxy-), 5.67, 5.90 (bs, 2H, -NH). ¹³C NMR (125.66 MHz, CDCl₃) (ppm) = 23.0, 23.7, 55.7 (-C), 44.4, 58.6 (-N-CH₂-CH₂-N-), 14.8 (-C), 66.1 (-C) 136.3, 140.5 (-C-NH-), 100.2 (C-Cl-), 127.8 (C-O-), 169.2, 175.0 (C=O). MS [+ESI] = 441.4 [M+2H]⁺, Anal. Calc. for C₂₂H₃₅ClN₄O₃ (439.0): C 60.19, H 8.04, N 12.76. Found: C 60.14, H 8.21, N 12.68%. UV-vis [CHCl₃, (nm)()]: 223(2.8), 292(3.0), 333(1.7), 483(1.5).

3. Results and Discussion

3.1. Chemistry

In this study that we have done, reactions of thiol and amine compounds with 2,3-dichloro-1,4-naphthoquinone and 2,3,5,6-tetrachloro-1,4-benzoquinone as a starting compounds were investigated. Firstly, the multicomponent reactions of 2,3-dichloro-1,4-naphthoquinone 1 with various thiol and amine nucleophiles were investigated. Similarly, 2,3,5,6-tetrachloro-1,4-benzoquinone 15 with various amine nucleophiles was investigated. As shown in Scheme 1, the reaction of 1 with different amines 2a, 2c, 2d, 2e, 2f, 2 g in ethanol in the presence of Na₂CO₃ gave known and unknown compounds 3a [16, 17], 3c, 3d, 3f, 3g [18], 4e. Compound 6b [19] obtained the reaction of 1 with 5b. The reaction of 3a with 5a gave compound 7a [20]. When 1 reacted with an equimolar amount of various amines and thiols in ethanol in the presence of sodium carbonate solution at room temperature but under different conditions, the corresponding products (3c, 3d, 3f, 3g, 4e, 6b, 7a) were obtained in different yields. All synthesized compounds were confirmed by spectroscopic methods comprising ¹H NMR and ¹³C NMR, FT-IR, elemental analysis, and MS.

Scheme 1: The synthesis of N-, S-, O-substituted naphthoquinone derivatives (3a, 3c-d, 3f-g, 4e, 6b, 7a).

In the second step of this study, different molar amount of N-substituted naphthoquinone compounds 9 [16, 21], 13 [16, 23] was reacted with sodium azide in DMF. The phenazine compounds 11 and 14 [22] were synthesized and compound 11 has not yet been described in the literature (Scheme 2).

Scheme 2: The synthesis of phenazine compounds 11 and 14 via the condensation reaction of naphthoquinones 9 and 13.

In the last step of this study, 2,3,5,6-tetrachloro-1,4-benzoquinone 15 compound was reacted with compounds containing N-nucleophiles (2b, 2c, 2 g, 16) that novel benzoquinones (17-25) not yet described in the literature were synthesized in Scheme 3. The synthesis, spectroscopic data (¹H NMR, ¹³C NMR, MS, UV, FT-IR), elemental analysis, and melting points of compounds were reported in studies. The ¹H NMR signal of the hydrogen atoms of the naphthoquinone unit of compounds 3c, 3d, 3f, 3g, 4e, 7a was observed at (CH) δ= 7.9-8.1 and 7.5-7.7 ppm like as doublet of doublets and triplet of triplets, respectively. Similarly, 6b, 11, 14 were observed at (CH) δ= 7.9-8.1 and 7.5-7.7 ppm like as multiplets, respectively. Substituted aromatic ring hydrogens showed peaks around 6.8-7.4 ppm. Aliphatic groups in compounds 3f, 7a were shifted to a higher field and displayed peaks at 0.8-1.2 ppm. The ¹³C NMR spectra of compound 3d gave two carbonyl signals at 177.5 and 179.9 ppm (C=O). Unlike other studies, the carbon atoms attached to the fluorine atoms in the 3c compound give cleavage peaks 155.6, 157.8 ppm (F-) in aromatic unit. Compound 3d gave one carbonyl signal at 116.6 ppm (-Cl-) similarly giving a single peak at 126.9 ppm in the compound 3f. The FT-IR spectra of compounds 3c, 3d, 3f, 3g, 4e, 7a showed bands around at 3300 cm⁻¹ for the (–NH) stretching. Also, (C-) bond was observed ν = 3000 cm⁻¹. With the aid of the positive ion mode of electron spray ionization (ESI) mass spectrum of the compounds 3c, 6b, and 3f, the respective molecular ion peaks were observed at m/z (%) 334 (100) [M+H]⁺, 411 (100) [M+H]⁺, 292 (100) [M+H]⁺, respectively.

Scheme 3: The synthesis of N,O-substituted benzoquinone derivatives.

2-Chloro-3-(o-tolylamino)naphthalene-1,4-dione 9 and sodium azide 10 required for the synthesis of 11, similarly, 2-chloro-3-(m-tolylamino)naphthalene-1,4-dione 13 and sodium azide (NaN₃) 10 required for the synthesis of compound 14 have been synthesized according to Scheme 2. The nucleophilic displacement reaction of compound 9 with sodium azide (NaN₃) in DMF-H₂O (10:1) afforded 1-methylbenzo[b]phenazine-6,11-dione 11 and this analog 2-methylbenzo[b]phenazine-6,11-dione 14 as the only isolated products as exhibited in Scheme 2. The proposed mechanism of condensation reaction of naphthoquinones agrees well with the related literatures [24, 25]. Both synthesized compounds were characterized by using the ¹H NMR, ¹³C NMR, FT-IR spectral data, and elemental analysis. The first compound 11 was obtained by an interesting ring closure and is a phenazine derivative. The ¹³C NMR spectra of compound 11 gave two carbonyl signals at 180.7 and 180.8 ppm (C=O). The FT-IR spectra of compounds 11 and 14 showed bands at 3019 cm⁻¹ for the (C-) stretching and (–NH) bonds were not observed in the FT-IR. ¹H NMR peak of the hydrogen atoms of the naphthoquinone group gave on (C) δ= 7.53-7.61 ppm and 7.95-7.99 ppm as multiplets for compound 11. Molecular ion peaks were observed at m/z (%) 276.1 (100) [M+2H]⁺. The UV-Vis spectroscopy values for compound 14 were also observed at 212(2.2), 241(2.1), 298(2.2), 539(1.2).

It is known that the reactions of 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4 dione 15 with amines proceed by Michael addition reaction. A series of 2-arylamino-1,4-benzoquinone derivatives 17-25 were synthesized via the nucleophilic substitution reaction of 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 by appropriate aryl amines 2c, 2 g, 2h, 16 in ethanol as shown in Scheme 3. The reactions were found to be exceptionally selective and lead to mainly 2- and/or 2,5-bis(amino substituted)-3,6-dichloro-1,4-benzoquinones of the corresponding amine. From these reactions we could not obtain 2,6-bis(amino substituted)-1,4-benzoquinone derivatives. The steric factors arising from the substituent effect predominates in these reactions. The result of selective formation of 2,5-isomer may be assumed to be due to attack of two amines to 1,4-benzoquinone. For such attack to give exclusive product of one isomer (2,5-) would require approach of two amines from the furthest possible distance. Thus, exclusively 2- and/or 2,5-isomer were formed due to electrostatic reasons for compounds 17-25. The results agree well with the corresponding mechanism in the similar compounds [6, 26].

In ¹H NMR spectrum of compounds 17-23, the hydrogen signals were observed at between δ = 6.1-8.0 ppm as multiplet peak, assigned to the (-C). In the ¹³C NMR, characteristic signals of two carbonyl carbons of benzoquinones were visible at around 175.9 and 173.8 ppm. For compound 23, substitute ethoxy group carbons (-C) and (-C) at 68.0 and 16.1 ppm, respectively. Like the naphthoquinone derivatives, carbon atoms attached to the fluorine atoms in the 23 compound give cleavage peaks 155.5 and 157.8 ppm (F-). The FT-IR spectra of compounds 17-25 showed the absorption bands of the N–H group at around 3240-3380 cm⁻¹. The characteristic stretching band of carbonyl groups (C = O) was observed at between ν = 1650-1700 cm⁻¹. In the MS of quinone derivatives, the molecular ion peaks of compounds 17, 22, and 23 were observed at 364 (100) [M]⁻, 445 (100) [M+2H]⁺, 360 (100) [M-H]⁻.

3.2. Antimicrobial Studies

The profound antifungal and antibacterial activity exhibited by quinone compounds has prompted us to synthesize new heteroatom substituted 1,4-naphtho- and benzoquinones. In our new endeavors, we have synthesized new 1,4-naphtho- and benzoquinones and evaluated their antibacterial and antifungal activity by diffusion [13] and serial dilution[14] methods with a view to search new perspective compounds having broad spectrum of biological activity. Antibacterial and antifungal activity of compounds 3c, 3d, 3f, 3g, 6b, 11, 17, 21, and 25 was elucidated against Escherichia coli B-906, Staphylococcus aureus 209-P, Mycobacterium luteum B-917, Candida tenuis VKM Y-70, and Aspergillus niger F-1119 by diffusion method (Tables 1 and 2) and by serial dilution method as shown in Tables 3 and 4. Activities of quinone compounds were compared with those of the known antibacterial agent vancomycin and antifungal agent nystatin (control C).

Table 1: Antibacterial activity of the compounds determined by diffusion method.

Compound
Concentration
%
Diameter of inhibition of growth of microorganisms, mm

E. coli
S. aureus
M. luteum

3c
0.5
0
0
0

0.1
0
0
0

3d
0.5
0
16
24

0.1
0
12
12

3f
0.5
0
0
0

0.1
0
0
0

3g
0.5
11
20
20

0.1
0
14
16

6b
0.5
0
0
11

0.1
0
0
8

11
0.5
0
0
0

0.1
0
0
0

17
0.5
0
10
11

0.1
0
6
9

21
0.5
0
0
0

0.1
0
0
0

25
0.5
0
0
0

0.1
0
0
0

Control
0.5
14
15
18

Vancomycin was used as a control in the tests of antibacterial activity of the synthesized compounds.

Table 2: Antifungal activity of the compounds determined by diffusion method.

Compound
Concentration
%
Diameter of inhibition of growth of microorganisms, mm

C. tenuis
A. niger

3c
0.5
0
0

0.1
0
0

3d
0.5
0
0

0.1
0
0

3f
0.5
0
0

0.1
0
0

3g
0.5
0
0

0.1
0
0

6b
0.5
15
0

0.1
13
0

11
0.5
0
0

0.1
0
0

17
0.5
0
15

0.1
0
10

21
0.5
7
12

0.1
0
6

25
0.5
15
10

0.1
0
0

Control
0.5
19
20

Nystatin was used in the tests of antifungal activity of the synthesized compounds.

Table 3: Antibacterial activity of the compound determined by serial dilution method.

Compound
Microorganism

E. coli
S. aureus
M. luteum

MIC (μg/mL)

3c
+
+
+

3d
+
62.5
31.2

3f
+
+
+

3g
250.0
31.2
15.6

6b
+
+
+

11
+
+
+

17
+
15.6
62.5

21
+
+
+

25
+
500.0
250.0

Control
31.2 ± 0.8
3.9 ± 0.2
7.8 ± 0.2

+: growth of microorganisms.

Table 4: Antifungal activity of the compounds determined by serial dilution method.

Compound
Microorganism

C. tenuis
A. niger

MIC (μg/mL)

3c
125.0
+

3d
+
+

3f
+
+

3g
500.0
500.0

6b
+
+

11
+
+

17
15.6
250.0

21
62.5
125.0

25
31.2
250.0

Control
7.8 ± 0.2
15.6 ± 0.8

+: growth of microorganisms.

The test-culture E. coli appeared not to be sensitive to any compounds except that 3g. Compound 3g has moderate activity against E. coli at a concentration of 0.5% and the diameter of the inhibition zone was 11 mm by diffusion method. Compounds 3d and 3g have strong activity against S. aureus (16 and 20 mm at 0.5% concentration) and have moderate activity at a concentration of 0.1% (the diameter of the inhibition zones were 12 and 14 mm). The M. luteum strain was sensitive to compounds 3g, 6b, and 17 at a concentration of 0.5% and the diameter of the inhibition zone was 20 and 11 mm, respectively (Table 1). Compound 3d has good antibacterial activity against M. luteum at concentration of 0.5% and the diameter of the inhibition zone was 24 mm by diffusion method (for vancomycin was 18 mm). Compounds 3d and 3g were found to exhibit strong antibacterial activity against S. aureus and M. luteum (at concentration of 0.5%) on comparison with antibacterial drug vancomycin evaluated by diffusion method.

Antifungal activity against C. tenuis was observed for 6b, 21, and 25 at concentration of 0.5% (d = 15, 7 and 15 mm, respectively). Compound 17 showed antifungal activity against A. niger at 0.5% concentration (d = 15 mm) by the diffusion method (Table 2). Compounds 3c, 3f, and 11 have no antibacterial and antifungal activity against E. coli, S. aureus, M. luteum, C. tenuis, and A. niger at 0.5 and 0.1% evaluated concentrations by diffusion method (Tables 1 and 2).

The biological activity results of the synthesized compounds were classified as follows: the antimicrobial activities were considered as significant when the minimum inhibition concentration (MIC) was 100 μg/mL or less; moderate, when the MIC was 100.0–500.0 μg/mL; weak, when the MIC was 500.0–1.000 μg/mL; and inactive when the MIC was above 1.000 μg/mL. Evaluation of the antibacterial activity of the synthesized compounds showed that 3g and 17 was the most potent with MIC=15.6 μg/mL for M. luteum and S. aureus, respectively (Table 3). Evaluation of antibacterial activity of synthesized compounds showed that 3d and 3g have MIC=31.2 μg/mL for M. luteum and S. aureus, respectively (Table 3).

Significant antifungal activity for 17 and 25 was observed against C. tenuis fungi at 15.6 and 31.2 μg/mL, respectively. Evaluation of antifungal activity of compounds 3c, 3g, and 21 showed their activity in concentrations 62.5–500.0 μg/mL against test-culture C. tenuis (Table 4). Compounds 3g, 17, 21, and 25 showed moderate antifungal activity with MIC value in the range of 125.0–500.0 μg/mL against A. niger in Table 4.

3.3. Catalase Enzyme Inhibition Activity of Quinone Derivatives

Catalase is a common heme containing enzyme found in nearly all living organisms that are exposed to , where it functions to catalyze the decomposition of H₂O₂ to H₂O and . Compounds 3c, 3d, 3f, 3g, 4e, 6b, 7a, 14, 17, 19, 22, and 23 were tested in vitro for their catalase activities and the results are shown in Table 5 and Figure 1. As shown in Figure 1, compound 3g caused significant elevation of catalase activity.

Table 5: Catalase enzyme activities of the compounds.

Compound
Catalase activities

(U/mL)

3c
0.599

3d
0.705

3f
0.715

3g
0.722

4e
0.689

6b
0.606

7a
0.608

14
0.470

17
0.581

19
0.550

22
0.709

23
0.585

Figure 1: Catalase enzyme activities of the compounds, U .

4. Conclusion

In this study we have done, the aim is to synthesize known and unknown quinone derivatives by reacting quinone compounds with some nucleophiles such as containing sulfur, nitrogen, and oxygen atoms in various conditions. In the synthesized compounds, antimicrobial activity at low concentrations against E. coli, S. aureus, and M. luteum bacteria and C. tenuis and A. niger fungi in comparison with controls was identified. Furthermore, a catalase activity of benzo- and naphthoquinone derivatives was examined for the first time in this work. Their structures of new synthesized compounds were determined by microanalysis, FT-IR, ¹H NMR, ¹³C NMR, MS, and UV-Vis.

Compound 3d has good antibacterial activity against test-culture M. luteum at concentration of 0.5% and the diameter of the inhibition zone was 24 mm by diffusion method (for vancomycin was 18 mm). Compounds 3d and 3g were found to exhibit high antibacterial activity against S. aureus and M. luteum (at concentration of 0.5%) on comparison with antibacterial drug vancomycin evaluated by diffusion method. Then, inhibitory activities of the benzo- and naphthoquinone derivatives against catalase enzyme were measured and especially 3g exhibited better catalase enzyme inhibition activity than the other quinone derivatives.

Data Availability

The data used to support the findings of this study are available from the corresponding author upon request.

Conflicts of Interest

The authors declare no conflicts of interest.

Acknowledgments

The authors would like to express their gratitude to Scientific Research Projects Coordination Unit of Istanbul University for financial support (Projects nos. 43723 and 36017).

References

M. Batra, P. Kriplani, C. Batra, and K. G. Ojha, “An efficient synthesis and biological activity of substituted p-benzoquinones,” Bioorganic & Medicinal Chemistry, vol. 14, no. 24, pp. 8519–8526, 2006.

S. Ganapaty, P. Steve Thomas, G. Karagianis, P. G. Waterman, and R. Brun, “Antiprotozoal and cytotoxic naphthalene derivatives from Diospyros assimilis,” Phytochemistry, vol. 67, no. 17, pp. 1950–1956, 2006.

T. M. Silva, C. A. Camara, T. P. Barbosa et al., “Molluscicidal activity of synthetic lapachol amino and hydrogenated derivatives,” Bioorganic & Medicinal Chemistry, vol. 13, p. 193, 2005.

C. Biot, H. Bauer, R. H. Schirmer, and E. D. Charret, “5-Substituted tetrazoles as bioisosteres of carboxylic acids. Bioisosterism and mechanistic studies on glutathione reductase inhibitors as antimalarials,” Journal of Medicinal Chemistry, vol. 47, no. 22, pp. 5972–5983, 2004.

A. Mantyla, J. T. G. Rautio, T. Nevalainen et al., “Synthesis, in vitro evaluation, and antileishmanial activity of water-soluble prodrugs of buparvaquone,” Journal of Medicinal Chemistry, vol. 47, pp. 188–195, 2004.

N. G. Deniz, C. Ibis, Z. Gokmen et al., “Design, synthesis, biological evaluation, and antioxidant and cytotoxic activity of heteroatom-substituted 1,4-naphtho- and benzoquinones,” Chemical & Pharmaceutical Bulletin, vol. 63, no. 12, pp. 1029–1039, 2015.

V. K. Tandon, K. Maurya, N. Mishrab et al., “Micelles catalyzed chemoselective synthesis ‘in water’ and biological evaluation of oxygen containing hetero-1,4-naphthoquinones as potential antifungal agents,” Bioorganic & Medicinal Chemistry Letters, vol. 16, p. 5883, 2006.

P. L. Gutierrez, “Mechanism(s) of bioreductive activation. The example of diaziquone (AZQ),” Free Radical Biology and Medicine, vol. 6, no. 4, pp. 405–455, 1989.

M. Stasevych, V. Zvarych, V. Lunin et al., “Computer-aided prediction and cytotoxicity evaluation of dithiocarbamates of 9,10-anthracenedione as new anticancer agents,” SAR and QSAR in Environmental Research, vol. 28, no. 5, pp. 355–366, 2017.

V. Zvarych, M. Stasevych, V. Lunin et al., “Synthesis and investigation of antioxidant activity of the dithiocarbamate derivatives of 9,10-anthracenedione,” Monatshefte für Chemie, vol. 147, no. 12, pp. 2093–2101, 2016.

C. Sayil and C. Ibis, “Synthesis of N-, S-, O-substituted quinone dyes and their dyeability on polyester fibers,” Bulletin of the Korean Chemical Society, vol. 31, no. 5, p. 1233, 2010.

K. Takagi, A. Mizuno, A. Iwamoto, M. Furusyo, and M. Matsuoka, “Spectral properties of tetrathiabenzoquinones and their self-assembly in the solid state,” Dyes and Pigments, vol. 36, no. 1, pp. 35–43, 1998.

P. R. Murray, E. J. Baron, M. A. Pfaller, F. C. Tenover, and R. H. Yolken, Manual of clinical microbiology, vol. 6, ASM Press, Washington, wash, USA, 1995.

National Committee for Clinical Laboratory Standard, Reference method for broth dilution antifungal susceptibility testing of conidium forming filamentous fungi: proposed standard, Document M38-P, Wayne, NJ, USA, 1998.

B. Bekdeser, M. Ozyurek, K. Guclu, F. Alkan, and R. Apak, “Development of a new catalase activity assay for biological samples using optical CUPRAC sensor,” Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, vol. 132, p. 485, 2014.

C. Sayil, S. Kurban, and C. Ibis, “Synthesis and characterization of nitrogen and sulfur containing 1,4-naphthoquinones,” Phosphorus, Sulfur, and Silicon and the Related Elements, vol. 188, no. 12, pp. 1855–1867, 2013.

K. V. Tandon and K. M. Hardesh, “Design, synthesis and biological evaluation of novel nitrogen and sulfur containing hetero-1,4-naphthoquinones as potent antifungal and antibacterial agents,” European Journal of Medicinal Chemistry, vol. 44, no. 8, pp. 3130–3137, 2009.

H. J. Kallmayer and N. Petesch, “Photoreactions of Compounds containing Heteroatoms other than Oxygen,” Pharmaceutica Acta Helvetiae, vol. 66, p. 130, 1991.

N. G. Clark, “The fungicidal activity of substituted 1,4-naphthoquinones,” Pesticide Science, vol. 15, pp. 235–240, 1984.

H. Sekioka and Y. S. Hirota, “Japanese Kokai Tokkyo Koho JP 54126725 A 19791002, 1979”.

J. Benites, J. A. Valderrama, K. Bettega et al., “Biological evaluation of donor-acceptor aminonaphthoquinones as antitumor agents,” European Journal of Medicinal Chemistry, vol. 45, p. 6052, 2010.

J. A. Vanallan, G. A. Reynolds, and R. E. Adel, “Polynuclear heterocycles. IV. The synthesis of some new heterocyclic quinones,” The Journal of Organic Chemistry, vol. 28, no. 2, pp. 524–527, 1963.

N. G. Clark, “The fungicidal activity of substituted 1,4‐naphthoquinones. Part III: Amino, anilino and acylamino derivatives,” Journal of Pest Science, vol. 16, no. 1, p. 23, 1985.

S. Kurban, N. G. Deniz, and C. Sayil, “Synthesis and cyclization reactions of novel benzo[a]phenazine- and phenoxazine5-ones derivatives,” Bulgarian Chemical Communications, vol. 48, p. 43, 2016.

A. F. Tuyun, N. Bayrak, H. Yildirim et al., “Synthesis and in vitro biological evaluation of aminonaphthoquinones and benzo [b] phenazine-6, 11-dione derivatives as potential antibacterial and antifungal compounds,” Journal of Chemistry, vol. 1, 2015.

C. Ibis, M. Yildiz, and C. Sayil, “The Synthesis of Novel Mono(alkoxy)-, Tris(thio)- and Tetrakis(thio)-Substituted Quinones from the Reactions of p-Chloranil with Various S-Nucleophiles,” Bulletin of the Korean Chemical Society, vol. 30, no. 10, p. 2381, 2009.