The Reaction between Acetone and Ammonia. II. Isomeric Oximinoketones related to Diacetoamine

Abstract

The compound 2,2,4,4,6-pentamethyltetrahydropyrimidine hydrate, formed in the reaction between acetone and ammonia at room temperature: is converted by nitrous acid to the 5-oximino derivative in 30 per cent. yield. This oxime is decomposed by acid under mild conditions to give acetone, ammonia, and the salt of 4-amino-4-methyl- 2,3-pentanedione 3-oxime. More vigorous acid treatment of the cyclic oxime, or reaction of the open-chain 3-oxime with boiling dilute acid, causes a migration of the oximino group to the 2 position. Evidence is adduced to show that the 2-oxinze has the α- (anti) configuration, whereas the 3-oxime has the β- (syn) configuration.