An efficient method for the synthesis of
Solvent-free reactions obviously reduce pollution and bring down handling costs due to simplification of experimental procedure, work-up technique, and saving energy. These would be especially important during industrial production [
All chemicals were purchased from Merck chemical company. Melting points were recorded on an electrothermal melting point apparatus. The NMR spectra were recorded in CDCl3 with TMS as an internal standard on a Bruker advance DRX 400 MHz spectrometer. IR spectra were determined on a SP-1100, P-UV-Com instrument. Elemental analyses were performed using a CHN-O Rapid Heraeus elemental analyser (Wellesley, MA). Purity determination of the products was accomplished by TLC on silica gel polygram SIL G/UV 254 plates. Products were identified by comparison of the obtained FT-IR and 1H NMR spectra with those reported for authentic samples.
A solution of 5 mmol nitrile in 5 mmol
M.p.: 96-97°C. IR (KBr)
M.p.: 189–192°C. FT- IR (KBr):
M.p.: 272–276°C. FT-IR (KBr):
M.p.: 204–207°C. IR (KBr)
A variety of
Amidation of
Entry | Substrate | Nitrile | Amidea | Time/h | Yield %b |
---|---|---|---|---|---|
|
(CH3)3COAc | C6H5CN | C6H5CONHtBu | 2 | 90 |
|
(CH3)3COH | C6H5CN | C6H5CONHtBu | 2.30 | 88 |
|
(CH3)3COAc |
|
|
2 | 92 |
|
(CH3)3COH |
|
|
3 | 90 |
|
(CH3)3COAc |
|
|
2 | 88 |
|
(CH3)3COH |
|
|
2.30 | 85 |
|
(CH3)3COAc |
|
|
2 | 94 |
|
(CH3)3COH |
|
|
2 | 92 |
|
(CH3)3COAc |
|
|
4 | 76 |
|
(CH3)3COH |
|
|
4 | 70 |
|
(CH3)3COAc |
|
|
4.30 | 92c |
|
(CH3)3COH |
|
|
5 | 90c |
|
(CH3)3COAc |
|
|
4.30 | 88c |
|
(CH3)3COH |
|
|
5 | 86c |
|
(CH3)3COAc | CH2=CHCN | CH2=CHCONHtBu | 3 | 66 |
|
(CH3)3COH | CH2=CHCN | CH2=CHCONHtBu | 4 | 60 |
|
(CH3)3COAc | ClCH2CN | ClCH2CONHtBu | 3.5 | 45 |
|
(CH3)3COH | ClCH2CN | ClCH2CONHtBu | 4 | 42 |
|
(CH3)3COAc | NCCH2COOEt | tBuNHCOCH2COOEt | 3.5 | 54 |
|
(CH3)3COH | NCCH2COOEt | tBuNHCOCH2COOEt | 4 | 48 |
|
(CH3)3COAc | CH3CN | CH3CONHtBu | 8 | 48 |
|
(CH3)3COH | CH3CN | CH3CONHtBu | 9 | 45 |
The formation of
In conclusion, we have developed a simple, inexpensive, and ecofriendly methodology for modified Ritter reaction that represents effective activity for the amidation of
The authors declare that there is no conflict of interests regarding the publication of this paper.
The authors are grateful to Islamic Azad university of Rasht Branch for financial assistance of this work.