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Oxidative cyclization of n-methyl- and n-benzoylpyridylthioureas. Preparation of new thiazolo[4,5-b] and [5,4-b] pyridine derivatives

✍ Scribed by Karine Jouve; Jan Bergman

Publisher
Journal of Heterocyclic Chemistry
Year
2003
Tongue
English
Weight
75 KB
Volume
40
Category
Article
ISSN
0022-152X

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✦ Synopsis

Abstract

Cyclization of N‐methyl‐ and N‐benzoylpyridylthioureas, prepared from the corresponding aminopy‐ridines, has been realized using various conditions. With bromine in acetic acid or potassium ferricyanide, the cyclization occurred on the nitrogen of the pyridine ring and pyridinium salts or 1,2,4‐fhiadiazolo[2,3‐a]pyridylidene systems were obtained. On the other hand, treatment of the thioureas with sodium methoxide in N‐methylpyrrolidinone (NMP) led to formation of fhiazolo[4,5‐b] and [5,4‐b]pyridines, which are interesting targets for biological evaluation.

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