HETEROCYCLIC OXAZOLONES AND THEIR PREPARATION

摘要

A heterocyclic oxazolone of formula (I) is prepd. by (a) reacting a bromoketone of formula (II) with a cyanate salt to obtain an isocyanate of formula (III), and (b) cyclizating (III) in the absence of solvents by heating. In the formulas, Y is O ; R1 is R ; R2 is hydrogen or C1-5 alkyl ; R is (un)substituted 2-,3- or 4-pyridil. (I) is useful as a cardiac.