Prodn. of cardiotonic 4-pyridoyl-2-imidazolone cpds.

摘要

Prodn. of 4-pyridoyl-2-imidazolones of formula (I) is effected by (a) reducing a diketo-oxime of formula (II) to form a hydroxy-amino-ketone of formula (III); (b) sycyclising (III) by reaction with cyanate ions to form a 4-pyridylhydroxymethyl-2-imidazolone of formula (IV); and (c) oxidising (IV). In the formula, Ar = 2-, 3- or 4-pyridyl; R1 = H or 1-4C alkyl. Also claimed is the prepn. of (III) by redn. of (II) and the prepn. of (IV) by reaction of (III) with an alkali(ne earth) metal cyanate.