Abstract

STUDIES ON BIO-ACTIVE POLYHETEROCYCLES: SYNTHESIS OF 4-ARYLOXYMETHYL-2H-THIOPYRANO[3,2-C][1]-9-METHYLBENZOPYRAN-5(2H)-ONES THROUGH THIO-CLAISEN REARRANGEMENT

S. K. Ghosh*

ABSTRACT

The sulfides 4-[4-aryloxybut-2-ynylthio][1]-6-methylbenzopyran-2-ones 5(a-f) were prepared in 80-87% yield by the phase transfer-catalysed of 6-methyl-4-mercaptocoumarin 3 with 1-chloro-4-aryloxybut-2-yne 4(a-f). Substrates 5(a-f) were heated in chlorobenzene to yield 4-aryloxymethyl-2H- thiopyrano[3,2-c][1]-9-methylbenzopyran-5(2H)-ones 6a-f in excellent yield.

Keywords: Thio-Claisen Rearrangement, 6-methyl-4- mercaptocoumarin, 1-chloro-4-aryloxybut-2-yne, Phase-transfer catalyst, 6-methyl-4-hydroxycoumarin.