2. Experimental
2.1. Chemistry
Chemicals used in present work were of analytical grade obtained from E-Merck (Germany), Sigma Aldrich (USA), and BDH (UK) without further purification to synthesize desired compounds, and high purity water (0.01 μS/cm) was prepared in our own laboratory using Milli-Q purification system (USA). Alpha IR spectrometer (FTIR-ATR) and NMR spectrometer, Bruker, were used to record the IR and 1HNMR (500 MHz) and 13CNMR (125 MHz) spectra, respectively. PG-T80+ UV-Vis spectrophotometer (UK) and Flash HT Plus elemental analyzer (Thermo Scientific, UK) were used for
λ
m
a
x
, and concentration of hydrogen (H), carbon (C), nitrogen (N), and sulfur (S) of synthesized compounds, respectively, while the melting point was measured by Gallenkamp apparatus. JMS-HX-110 spectrometer with electron spray ionization (ESI) interface was used for mass spectra. The 1HNMR and 13CNMR spectra of all the synthesized compounds were measured using MeOD and concentration of all the compounds was 10–20 mg in 0.8–1.0 mL of solvent. Purification and progress of the synthesized compounds were confirmed on precoated TLC silica plate (Merck-Germany).
2.2. Antimicrobial Assay
Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Aspergillus flavus ATCC 9643, Aspergillus parasiticus ATCC 15517, and Acremonium sp. ATCC 200667 were collected from Mycology Department, University of Punjab, Lahore, Pakistan, and were maintained in tryptic soy agar (TSA) and potato dextrose agar (PDA) medium, respectively, slants at 5°C until use. A series of four 2-fold dilutions (320, 160, 80, and 40 μg/mL) were made from stock solution of 640 μg/mL in dimethyl sulphoxide (DMSO). All the dilutions were made sterile in an autoclave at 121°C for 30 min with 15 psi pressure after filtration through 0.22 μm membrane filter. The minimal inhibitory concentration (MIC) was reported as absence of no observable growth by the lowest concentration of tested compounds after twofold serial dilution. Five individually numbered test tubes with screw caps were sterilized. Tube 1 was filled with 2 mL of tryptic soy broth culture media including the stock solution of synthesized compounds. 1.0 mL of this solution was introduced into 2 tubes and diluted with 1.0 mL culture media and we repeated the procedure up to tube 5. The tubes were incubated at 25°C for 72 hrs. Ciprofloxacin and sulfamethoxazole (sulfa drug) were used as reference (positive control to check the sensitivity of tested bacterial strains).
1
–
3
×
10
8
cfu/mL of each of Gram negative E. coli and Gram positive S. aureus and B. subtilis was obtained after adjusting the optical density of inoculum at 0.2–0.3 and 0.3–0.4 (620 nm), respectively, while fungal suspension (A. flavus, A. parasiticus, and A. sp.) with cell density of 105 cfu/mL was studied in present work and the itraconazole was used as reference antifungal agent. All the compounds and reference solutions were applied (50 μL) onto a 6 mm sterile filter paper disc separately and the inoculated plates incubated at 37°C for 24 hrs. The zones of inhibition (mm) were measured and we evaluated the antibacterial activities.
2.3. General Procedure for Synthesis of Sulfonamides
A simple method in aqueous media under dynamic pH control is adopted for synthesis of sulfonamides. Filtration after acidification is involved for isolation of products [19–21]. All the amines were weighed accurately and dissolved completely by addition of distilled water by constant stirring using magnetic stirrer. The pH of the reaction contents was strictly monitored and maintained at 8–10 at regular intervals during the experimental reaction using Na2CO3 solution (1 M). Then benzene sulfonyl chloride or p-toluene sulphonyl chloride was accurately weighed and added carefully into the above solution. The reaction was carried in round bottom flask equipped with magnetic stirrer. During stirring sulphonyl chloride initially floats on the surface and the completion of reaction was examined by the change in pH value due to formation of HCl by the consumption of sulphonyl chlorides during the reaction. On completion of the reaction pH was adjusted at 2-3 using HCl solution (2 M). The precipitates formed were filtered through Whatman filter paper number 42, washed several times with distilled water, and recrystallized using methanol and dried using rotary evaporator.
2.4. N-
{
Imino[(phenylsulfonyl)amino]methyl}-N-methylglycine (3a, C10H13N3O4S)
Yield: 397.9 mg (64.7%); m.p.: 172–174°C; TLC:
R
f
=
0.72
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
=
3215
(O-
H
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 3084 (C-
H
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1768 (C=
O
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1707 (C=
N
i
m
i
n
e
,
s
t
r
e
t
c
h
i
n
g
), 1438 (O-
H
c
a
r
b
o
x
y
l
i
c
,
b
e
n
d
i
n
g
), 1033 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1165 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1458 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 706 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(ε) = 208 (25050) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD)
δ
=
9.91
(br, s, 1H, NH), 7.98 (d,
J
=
7.48
Hz, 1H, CH), 7.68 (t,
J
=
7.59
Hz, 1H, CH), 7.56 (d,
J
=
7.63
Hz, 1H, CH), 4.71 (d,
J
=
13.16
Hz, 2H, CH2), 3.15 (s, 3H, CH3); 13CNMR (125 MHz, MeOD)
δ
=
168
(C-16), 155 (C-11), 141 (C-1), 135 (C-4), 129 (C-3), 51 (C-15), 35 (C-14); ESI-MS: m/z = 273.38 [M + 2]+, 271.31 [M]+.
2.5. N-(Imino
{
[(4 methylphenyl)sulfonyl]amino}methyl)-N-methylglycine (3b, C11H15N3O4S)
Yield: 779.9 mg (82.7%); m.p.: 185–187°C; TLC:
R
f
=
0.64
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
= 3224 (O-
H
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 2992 (C-
H
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1767 (C=
O
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1699 (C=
N
i
m
i
n
e
,
s
t
r
e
t
c
h
i
n
g
), 1438 (O-
H
c
a
r
b
o
x
y
l
i
c
,
b
e
n
d
i
n
g
), 1028 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1199 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1498 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 701 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 222 (22500) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD)
δ
=
9.96
(br, s, 1H, NH), 7.71 (s, 1H, CH), 7.38 (d,
J
=
8.11
Hz, 1H, CH), 4.68 (s, 2H, CH2), 3.15 (s, 3H, CH3), 2.26 (s, 3H, CH3); 13CNMR (125 MHz, MeOD)
δ
=
168
(C-17), 156 (C-12), 143 (C-1), 138 (C-4), 129 (C-2), 52 (C-16), 35 (C-15), 22 (C-7); ESI-MS: m/z = 287.39 [M + 2]+, 285.34 [M]+.
2.6. N-[[Bis(phenylsulfonyl)amino](imino)methyl]-N-methylglycine (4a, C16H17N3O6S2)
Yield: 931.8 mg (81.3%); m.p.: 210–212°C; TLC:
R
f
=
0.67
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
= 3062 (O-
H
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1767 (C=
O
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1621 (C=
N
i
m
i
n
e
,
s
t
r
e
t
c
h
i
n
g
), 1445 (O-
H
c
a
r
b
o
x
y
l
i
c
,
b
e
n
d
i
n
g
), 1037 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1163 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1445 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 689 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 210 (17250) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD) δ = 10.86 (br, s, 1H, NH), 8.21 (t,
J
=
7.61
Hz, 1H, CH), 8.08 (d,
J
=
7.61
Hz, 1H, CH), 7.93 (s, 1H, CH), 4.75 (s, 2H, CH2), 3.16 (s, 3H, CH3); 13CNMR (125 MHz, MeOD) δ = 168 (C-25), 156 (C-13), 141 (C-1), 132 (C-4), 131 (C-5), 53 (C-24), 37 (C-23); ESI-MS: m/z = 413.59 [M + 2]+, 411.48 [M]+.
2.7. N-[
{
Bis[(4-methylphenyl)sulfonyl]amino}(imino)methyl]-N-methylglycine (4b, C18H21N3O6S2)
Yield: 872.1 mg (82.2%); m.p.: 195–197°C; TLC:
R
f
=
0.63
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
=
3265
(O-
H
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1707 (C=
O
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1600 (N-
H
a
m
i
n
e
,
b
e
n
d
i
n
g
), 1660 (C=
N
i
m
i
n
e
,
s
t
r
e
t
c
h
i
n
g
), 1399 (O-
H
c
a
r
b
o
x
y
l
i
c
,
b
e
n
d
i
n
g
), 1043 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1182 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1445 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 685 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 222 (19000) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD) δ = 10.76 (br, s, 1H, NH), 7.81 (d,
J
=
8.11
Hz, 1H, CH), 7.78 (d,
J
=
8.14
Hz, 1H, CH), 4.73 (s, 2H, CH2), 3.15 (s, 3H, CH3), 2.46 (s, 3H, CH3); 13CNMR (500 MHz, MeOD) δ = 168 (C-27), 156 (C-14), 143 (C-1), 139 (C-4), 132 (C-6), 53 (C-26), 37 (C-24), 21 (C-25); ESI-MS: m/z = 441.53 [M + 2]+, 439.58 [M]+.
2.8. N-
{
Imino[[(4-methylphenyl)sulfonyl](phenylsulfonyl) amino]methyl}-N-methylglycine (6a, C17H19N3O6S2)
Yield: 626.4 mg (70.6%); m.p.: 182–184°C; TLC:
R
f
=
0.61
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
= 3277 (O-
H
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1707 (C=
O
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1599 (N-
H
a
m
i
n
e
,
b
e
n
d
i
n
g
), 1659 (C=
N
i
m
i
n
e
,
s
t
r
e
t
c
h
i
n
g
), 1399 (O-
H
c
a
r
b
o
x
y
l
i
c
,
b
e
n
d
i
n
g
), 1040 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1185 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1444 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 684 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 218 (26150) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD) δ = 10.79 (br, s, 1H, NH), 8.21 (d,
J
=
7.61
Hz, 1H, CH), 8.10 (s, H, CH), 7.91 (s, H, CH), 7.87 (d,
J
=
8.11
Hz, 1H, CH), 7.73 (s, H, CH), 7.73 (d,
J
=
8.01
Hz, 1H, CH), 4.73 (s, 2H, CH2), 3.15 (s, 3H, CH3), 2.44 (s, 3H, CH3); (125 MHz, MeOD) δ = 168 (C-26), 156 (C-14), 143 (C-1), 141 (C-17), 132 (C-20), 131 (C-2), 129 (C-3), 53 (C-25), 39 (C-24), 23 (C-7); ESI-MS: m/z = 427.53 [M + 2]+, 425.48 [M]+.
2.9. N-(Pyridin-2-yl)benzene Sulfonamide (9a, C11H10N2O2S)
Yield: 869.6 mg (83.1%); m.p.: 145–147°C; TLC:
R
f
=
0.61
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
= 3367 (N-
H
a
m
i
n
e
,
s
t
r
e
t
c
h
i
n
g
), 1666 (N-
H
a
m
i
n
e
,
b
e
n
d
i
n
g
), 1024 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1177 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1445 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 687 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 230 (43800) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD) δ = 11.49 (br, s, 1H, NH), 7.91 (d,
J
=
5.21
Hz, 1H, CH), 7.81 (d,
J
=
7.61
Hz, 1H, CH), 7.65 (t,
J
=
8.31
Hz, 1H, CH), 7.61 (t,
J
=
7.51
Hz, 1H, CH), 7.55 (t,
J
=
7.61
Hz, 1H, CH), 7.25 (t,
J
=
7.21
Hz, 1H, CH), 7.15 (d,
J
=
8.39
Hz, 1H, CH); 13CNMR (125 MHz, MeOD) δ = 148 (C-2), 145 (C-6), 140 (C-11), 137 (C-4), 132 (C-14), 129 (C-13), 127 (C-12), 115 (C-5), 112 (C-3); ESI-MS: m/z = 236.31 [M + 2]+, 234.28 [M]+.
2.10.
4-Methyl-N-(pyridin-2-yl)benzene Sulfonamide (9b, C12H12N2O2S)
Yield: 935.6 mg (82.1%); m.p.: 178–180°C; TLC:
R
f
=
0.72
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
= 3328 (N-
H
a
m
i
n
e
,
s
t
r
e
t
c
h
i
n
g
), 1665 (N-
H
a
m
i
n
e
,
b
e
n
d
i
n
g
), 1019 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1161 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1455 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 680 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 224 (15380) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD) δ = 11.43 (br, s, 1H, NH), 7.97 (d,
J
=
8.11
Hz, 1H, CH), 7.61 (d,
J
=
8.31
Hz, 1H, CH), 7.25 (t,
J
=
7.21
Hz, 1H, CH), 7.20 (s, 1H, CH), 7.11 (t,
J
=
8.41
Hz, 1H, CH), 7.15 (d,
J
=
8.39
Hz, 1H, CH), 2.48 (s, 3H, CH3); 13CNMR (125 MHz, MeOD) δ = 148 (C-2), 145 (C-6), 143 (C-14), 137 (C-4), 129 (C-13), 115 (C-5), 111 (C-3), 21 (C-17); ESI-MS: m/z = 250.35 [M + 2]+, 248.30 [M]+.
2.11. N-(Phenylsulfonyl)-N-(pyridin-2-yl)benzene Sulfonamide (10a, C17H14N2O4S2)
Yield: 909.8 mg (71.7%); m.p.: 166–168°C; TLC:
R
f
=
0.62
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
= 3348 (N-
H
a
m
i
n
e
,
s
t
r
e
t
c
h
i
n
g
), 1619 (N-
H
a
m
i
n
e
,
b
e
n
d
i
n
g
), 1030 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1186 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1445 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 688 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 215 (12830) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD) δ = 8.13 (m, 1H, CH), 8.11 (m, 1H, CH), 7.95 (m, 1H, CH), 7.88 (m, 1H, CH), 7.81 (m, 1H, CH), 7.65 (qd,
J
=
8.39
Hz, 1.21 Hz, 1H, CH), 7.48 (qd,
J
=
7.29
Hz, 5.21 Hz, 1H, CH); 13CNMR (125 MHz, MeOD) δ = 148 (C-6), 142 (C-13), 138 (C-2), 131 (C-16), 130 (C-14), 117 (C-5), 113 (C-3); ESI-MS: m/z = 376.45 [M + 2]+, 374.44 [M]+.
2.12.
4-Methyl-N-(phenylsulfonyl)-N-(pyridin-2-yl)benzene Sulfonamide (10b, C19H18N2O4S2)
Yield: 1140.5 mg (84.3%); m.p.: 164–166°C; TLC:
R
f
=
0.68
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
= 3348 (N-
H
a
m
i
n
e
,
s
t
r
e
t
c
h
i
n
g
), 1621 (N-
H
a
m
i
n
e
,
b
e
n
d
i
n
g
), 1027 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1162 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1445 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 681 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 222 (13855) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD) δ = 8.19 (s, H, CH), 8.02 (d,
J
=
8.09
Hz, 1H, CH), 7.87 (t,
J
=
8.41
Hz, 1H, CH), 7.68 (d,
J
=
8.11
Hz, 1H, CH), 7.61 (d,
J
=
8.37
Hz, 1H, CH), 7.55 (d,
J
=
7.27
Hz, 1H, CH), 2.46 (s, 3H, CH3); 13CNMR (125 MHz, MeOD) δ = 148 (C-6), 138 (C-2), 132 (C-15), 117 (C-5), 113 (C-3), 22 (C-27); ESI-MS: m/z = 404.55 [M + 2]+, 402.51 [M]+.
2.13.
4-Methyl-N-(phenylsulfonyl)-N-(pyridin-2-yl)benzene Sulfonamide (12a, C18H16N2O4S2)
Yield: 529.5 mg (65.1%); m.p.: 188–190°C; TLC:
R
f
=
0.76
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
= 3280 (N-
H
a
m
i
n
e
,
s
t
r
e
t
c
h
i
n
g
), 1620 (N-
H
a
m
i
n
e
,
b
e
n
d
i
n
g
), 1021 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1158 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1445 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 682 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 220 (42550) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD) δ = 8.15 (d,
J
=
7.69
Hz, 1H, CH), 8.07 (d,
J
=
8.11
Hz, 1H, CH), 7.98 (d,
J
=
7.61
Hz, 1H, CH), 7.91 (t,
J
=
8.37
Hz, 1H, CH), 7.65 (d,
J
=
8.17
Hz, 1H, CH), 7.51 (d,
J
=
7.17
Hz, 1H, CH), 7.45 (d,
J
=
7.17
Hz, 1H, CH), 2.44 (s, 3H, CH3); 13CNMR (125 MHz, MeOD) δ = 147 (C-6), 138 (C-2), 132 (C-15), 117 (C-5), 112 (C-3), 21 (C-27); ESI-MS: m/z = 390.53 [M + 2]+, 388.49 [M]+.
2.14. N-Methyl-N-(phenylsulfonyl)alanine (15a, C10H13NO4S)
Yield: 786.1 mg (51.7%); m.p.: 132–134°C; TLC:
R
f
=
0.72
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
= 3215 (O-
H
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1743 (C=
O
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1444 (O-
H
c
a
r
b
o
x
y
l
i
c
,
b
e
n
d
i
n
g
), 1041 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1183 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1444 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 688 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 215 (13070) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD) δ = 7.73 (d,
J
=
7.69
Hz, 1H, CH), 7.53 (d,
J
=
7.51
Hz, 1H, CH), 7.36 (t,
J
=
7.61
Hz, 1H, CH), 4.51 (q,
J
=
7.17
Hz, 1H, CH), 3.75 (br, s, 1H, OH), 2.71 (s, 3H, CH3), 1.11 (d,
J
=
7.17
Hz, 3H, CH3); 13CNMR (125 MHz, MeOD) δ = 178 (C-14), 138 (C-1), 131 (C-4), 62 (C-12), 29 (C-11), 15 (C-13); ESI-MS: m/z = 245.38 [M + 2]+, 243.35 [M]+.
2.15. N-Methyl-N-[(4-methylphenyl)sulfonyl]alanine (15b, C11H15NO4S)
Yield: 910.9 mg (63.6%); m.p.: 140–142°C; TLC:
R
f
=
0.70
(H2O-BuOH-Acetic acid 1 : 4 : 1); IR (FTIR):
υ
-
= 3268 (O-
H
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1710 (C=
O
c
a
r
b
o
x
y
l
i
c
,
s
t
r
e
t
c
h
i
n
g
), 1449 (O-
H
c
a
r
b
o
x
y
l
i
c
,
b
e
n
d
i
n
g
), 1054 (S=
O
s
t
r
e
t
c
h
i
n
g
), 1146 (-N- S=
O
s
t
r
e
t
c
h
i
n
g
), 1422 (C=C-
C
a
r
o
m
a
t
i
c
,
s
t
r
e
t
c
h
i
n
g
), 677 (
Ø
-
S
s
t
r
e
t
c
h
i
n
g
); UV-Vis (methanol,
c
=
2
·
10
-
5
mol dm−3):
λ
m
a
x
(
ε) = 220 (17250) nm (mol−1 dm3 cm−1); 1HNMR (500 MHz, MeOD) δ = 7.69 (d,
J
=
8.09
Hz, 1H, CH), 7.32 (d,
J
=
7.91
Hz, 1H, CH), 4.48 (t,
J
=
7.17
Hz, 1H, CH), 3.75 (br, s, 1H, OH), 2.69 (s, 3H, CH3), 2.39 (s, 3H, CH3), 1.08 (d,
J
=
7.17
Hz, 3H, CH3); 13CNMR (125 MHz, MeOD) δ = 178 (C-14), 138 (C-1), 133 (C-4), 129 (C-5), 61 (C-12), 29 (C-11), 15 (C-13); ESI-MS: m/z = 259.38 [M + 2]+, 257.35 [M]+.