A. Ya. Tikhonov

Reaction of substituted 4-phenylpyrimidine 1,3-dioxides with phosphorus oxychloride

Abstract2-Chloropyrimidine 1-oxides are formed in the reaction of substituted 4-phenylpyrimidine 1,3-dioxides with phosphorus oxychloride; in addition, 2,4-dichloropyrimidines and 3-phenylisoxazoles were isolated.

Reaction of 2,4,6-trialkylpyrimidine 1,3-dioxides with electrophilic reagents

The nitrosation of 2,4,6-trimethylpyrimidine 1,3-dioxide and the bromination of 2,4,6-trimethyl- and 2-ethyl-4,6-dimethylpyrimidine 1,3-dioxides take place primarily at the methyl groups in the 4 and 6 positions of the heteroring. In the reaction of 2,4,6-trimethylpyrimidine 1,3-dioxide with phosphorus oxychloride chlorine is incorporated in the methyl group in the 2 position of the heteroring, while in the reaction with acetic anhydride an acetoxy group is incorporated in the methyl group in the 2 position and in the 5 position of the heteroring, whereas in the case of tosyl chloride a tosyloxy group is incorporated in the 5 position of the heteroring.

Reaction of 1,3- hydroxylamino oximes with formaldehyde, acetaldehyde, and acetone

The products of condensation of 1,3-hydroxylamino oximes with formaldehyde have 1-hydroxy-1,2,5,6-tetrahydropyrimidine 3-oxide (cyclic form) structures, the products of condensation with acetone have N-(3-oximino-substituted)-α,α-dimethylnitrone (open form) structures, and the products of condensation with acetaldehyde exist in solution in the form of a tautomeric mixture of the open and cyclic forms. The products of condensation of alkyl-aromatic 1,3-hydroxylamino oximes with acetaldehyde have N-(3-oximino-substituted)-α-nitrone (open form) structures.