A facile synthesis of new thieno[2,3-b][1,4]thiazine derivatives starting from 2-acylamino-3,3-dichloroacrylonitriles

Abstract

Readily available 2‐acylamino‐3,3‐dichloroacrylonitriles are sequentially treated with methyl mercaptoacetate in the presence of sodium methylate and with sulfuric acid to furnish the methyl ester of 7‐amino‐2‐oxo‐3H‐thieno[2,3‐b][1,4]thiazine‐6‐carboxylic acid. Treating it first with triethyl orthoformate and then with ammonia or primary amines, the pyrimidine‐4‐one nucleus is annelated to the thienothiazine system, which is corroborated by spectroscopic methods and X‐ray diffraction analysis. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:411–415, 2006; Published online in Wiley InterScience (http://www.interscience.wiley.com). DOI 10.1002/hc.20232

Reactions of New N-(2,2-Dichloro-1-cyanoethenyl)amides with Aliphatic Amines

“…Previously, we have shown that substituted 2-acylamino-3,3-dichloroacrylonitriles can be used to produce various heterocycles such as thiophene [1], hydantoin [2], and indole derivatives [3]. However, most reactions of 2-acylamino-3,3-dichloroacrylonitriles with amines provide oxazole derivatives [4][5][6].…”

“…According to the data of liquid chromatography-mass spectra, compound 5 is probably also present in the reaction mixture; however, we failed to isolate it in an individual state. The reaction of dichloroacrylonitrile 2 with ethylenediamine diacetate resulted in the formation of (Z)-2,3,5,6,7,8-hexahydro-7-oxo-1H-imidazo[1,2-a] [1,4]diazepine-9-carbonitrile 6. A plausible mechanism for the formation of compound 6 includes the formation of intermediates A and B (Scheme 2).…”

“…IR spectrum, ν, cm -1 : 1464, 1604, 1654 sh, 2204 (CN). 1 H NMR spectrum (CDCl 3 ), δ, ppm: 1.97 s (6Н, СН 3 ), 2.36 t (2Н, СН 2 , 3 J HH 7.0 Hz), 2.45 t (2Н, СН 2 , 3 J HH 7.0 Hz), 2.83 s (6Н, СН 3 ). 13 C NMR spectrum (CDCl 3 ), δ С , ppm: 24.9 (CH 2 ), 37.…”

“…IR spectrum, ν, cm -1 : 1432, 1480, 1503, 1608, 1654, 2172 (CN), 3044-3243 (NH). 1 H NMR spectrum (DMSO-d 6 ), δ, ppm: 2.46 t (2Н, СН 2 , 3 J HH 5.4 Hz), 3.29-3.34 br. m (2Н, СН 2 ), 3.42 t (2Н, СН 2 , 3 J HH 5.4 Hz), 3.47 t (2Н, СН 2 , 3 J HH 8.1 Hz), 6.27 s (1Н, NH), 8.30 s (1Н, NH).…”