Pyrimidine derivatives and related compounds. 38. Synthesis of 1,3-oxazine-2,4-diones and their reaction with nucleophiles. Ring transformation of 1,3-oxazines to pyrimidines
作者:Motoi Yogo、Kosaku Hirota、Shigeo Senda
DOI:10.1002/jhet.5570180607
日期:1981.10
the corresponding 6-chloro derivatives (1 and 2). Treatment of 6-chloro-3-methyl-1,3-oxazine-2,4-dione (1a) with sodium azide, sodium cyanide, secondary amines and aniline gave the corresponding 6-substituted compounds (7, 9, 10 and 11) while the reaction of 1a and 2a,b with primary aliphatic amines such as methylamine and ethylamine caused a ring transformation to pyrimidine ring system giving barbituric
Pyrimidine derivatives and related compounds. XLIII. Studies on the mechanism of the ring transformation of 6-chloro-1,3-oxazine-2,4-diones to barbituric acids.
作者:MOTOI YOGO、KOSAKU HIROTA、SHIGEO SENDA
DOI:10.1248/cpb.30.1333
日期:——
The mechanism of the ring transformation of 6-chloro-1, 3-oxazine-2, 4-diones (1) into barbituric acids (2) in the presence of primary aliphatic amines was studied. It has been elucidated that the mechanism involves initial attack on the 2-position of 1 by an amine and subsequent intramolecular cyclization of the ureide intermediate (5).