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Reactions of 1,3‐thiazine‐2,6‐dithiones. Part 7 . Formation reactions of 3‐thioureidocinnamthioamides, 3‐[bis(alkylthio)methyleneamino]‐ and 3‐[bis(alkoxy)methyleneamino]‐dithiocinnamic acid esters by the thiazine ring opening reactions with primary amines, thiols, and alcohols. Recyclizing reactions of the acyclic thioamides and the alkyl dithiocinnamates and some related compounds
Author(s) -
Yamamoto Tatsuo,
Muraoka Motomu
Publication year - 1988
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570250327
Subject(s) - thiazine , chemistry , alkyl , medicinal chemistry , alkoxy group , iodide , pyrimidine , organic chemistry , stereochemistry
2‐Alkylamino‐ and 2‐arylamino‐1,3‐thiazine‐6‐thiones 3 were synthesized by the reactions of 1,3‐thiazine‐2,6‐dithiones 1 or 2‐methylthio‐1,3‐thiazine‐6‐thiones 2 with aliphatic or aromatic primary amines. 3‐(3‐Alkyl‐thioureido)cinnamthioamides 4 were formed on treatment of compounds 3 with primary amines. The same compounds 4 formed pyrimidine‐2,4‐dithiones 5 and primary amines by acid‐catalyzed intramolecular cyclization and the primary amines and compounds 5 gave compounds 4 quantitatively ( vice versa ). Further, treatment of compounds 4 ( R 3 = butyl, pentyl, hexyl) with hydrochloric acid or thermolysis of 4 gave rise to 2‐alkylimino‐6‐amino‐1,3‐thiazine‐5‐( N ‐alkyl)carbothioamides 6 accompanied by compounds 5. Compounds 3 , when allowed to react with the amines in aqueous ethanol gave 3‐alkyl‐2‐alkylaminopyrimidine‐6‐thiones 8 in addition to compounds 4 by two types of reactions occuring simultaneously. On the other hand, compounds 2 , when treated with thiols and alcohols instead of primary amines in the presence of alkyl iodide, yielded alkyl 3‐[bis(alkylthio)methyleneamino]dithiocinnamates 11 and alkyl 3‐[bis(methoxy)methyleneamino]dithiocinnamates 14 respectively. The mechanisms of the formation of these cyclic and acyclic compounds here obtained are also discussed in some detail.