A new route for the convenient synthesis of 3-(thiazol-2'-ylthio)-2h-1-benzopyran-2-ones

✍ Scribed by V.K. Ahluwalia; H.R. Sharma; R. Tyagi

• Publisher: Elsevier Science
• Year: 1987
• Tongue: French
• Weight: 355 KB
• Volume: 43
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(01)90053-5

✦ Synopsis

Different thiaxolvlthiocoumarins were prepared by the reaction of (thiaxol-2-ylthio) acetic acid hydra&d& with-2hydroxybenxaldehydes, followed by cyclixation of the formed N-benzylidene derivatives in presence of PPA.

A variety of coumarins 1,2 ,thiaxoles3'4 and thiazolylcoumarins 5-9 derivatives have been reported for their importance in pharmaceutical, therapeutic and commercial fields. Although a number of methods have been reported for the synthesis of 5-9 thiazolylcoumarins , the title compounds have not so far been synthesised.

In this paper we describe a new route for the synthesis of thiaxolylthiocoumarins involving the cyclixation of the N-benzylidene derivatives of (thiazol-2ylthio)acetic acid hydraxides in presence of PPA. Treatment of appropriate 2-mercaptothiaxoles (A,2-J1') with ethyl bromoacetate gave the corresponding ethyl(thiaxol-2-ylthio)acetates(41!~,~),which on reaction with hydraxine afforded the required (thiazol-2-ylthiojacetic acid hydraxides (1 12,&J+ Compounds (7-9)