Studies on 1, 3-Benzoxazines. VII. Formation of Diphenylpyrimidines by the Reaction of 4-Chloro-2H-1, 3-benzoxazines with Ethyl 3-Aminobutyrate

Abstract

A new reaction mode for the formation of pyrimidine derivatives by the reaction of 4-chloro-2H-1, 3-benzoxazines (1a-f) with ethyl 3-aminobutyrate is described. Treatment of chlorobenzoxazines (1a-f) with ethyl 3-aminobutyrate (2) gave pyrimidine derivatives (4a-f) possessing an o-hydroxyphenyl substituent. When 4-chloro-2-methyl-2-methoxycarbonylmethyl-2H-1, 3-benzoxazine (1g) was treated with 2, a pyrimidinone derivative (7) was isolated. A possible mechanism for the formation of these reaction products is discussed.