A synthetic entry to isoxazolo[5,4‐<i>d</i>]pyrimidine‐4(5<i>H</i>)thione and isothiazolo[4,3‐<i>d</i>]isoxazole

Abstract

Abstract 4‐Thiocarbamoyl‐5‐aminoisoxazole 4 was used as a convenient starting material for preparing both isoxazolo[5,4‐ d ]pyrimidine‐4(5 H )thiones 5 and 4‐aminoisothiazolo[4,3‐ d ]isoxazole 6 . The structure of the latter compound was definitively assigned by X‐ray analysis.