Diazabutadienes in heterocyclic syntheses. Preparation of pyrimidin-6-ones by reaction of 4-dialkylamino-1,3-diaza-1,3-butadienes with 2-oxazolin-5-ones

Abstract 1-Aryl-4-dimethylamino-2-phenyl-1,3-diaza-1,3-butadienes ( 1 and 1-aryl-4-dimethylamino-2-methylthio-1,3-diaza-1,3-butadienes ( 7 reacted with 2-oxazolin-5-ones ( 2 ) to yield pyrimidin-6-ones ( 3 ) and ( 8 ) respectively as single diastereoisomers with reverse stereochemistry. Reaction of 1,2-diphenyl-4-methylthio-4-amino-1,3-diaza-1,3-butadienes ( 12 ) with ( 2 ) also yielded pyrimidin-6-ones ( 13 ).