183591-89-1Relevant academic research and scientific papers
Mechanistic aspects of the synthesis of 3-aminopyrroles from substituted 2-methyl-1,2-thiazolium salts or 3-amino-thioacrylamides
Rolfs, Andreas,Jones, Peter G.,Liebscher, Juergen
, p. 2339 - 2343 (1996)
The mechanism of the synthesis of 3-aminopyrroles 3 by ring transformation-desulfurisation of substituted 2-methyl-1,2-thiazolium salts 2 has been investigated. 3-Alkylideneaminothioacrylamides 4 and 2H-1,3-thiazines 5 could be synthesised by base treatment of 1,2-thiazolium bromides 2 and proved to be intermediates in the ring transformation-desulfurisation. Hitherto unknown bis(2-aminothiocarbonylvinyl)amines 6 are observed as by-products. When 3-phenacylaminothioacrylamide 1c is oxidised with hydrogen peroxide a novel pyrrole formation occurs to give 2-benzoylthiopyrrole 8a, where the sulfur atom is retained in the product. An erroneously reported 1,2-thiazolium-2-methanide 7 has been reassigned as 3-(4-nitrobenzylideneamino)thioacrylamide 4a on the basis of an X-ray crystal structure determination.
