Reactions of halogenomethanes in the vapour phase. Part 4. The reactions of imidazoles with chloroform at 550 °C, and a comparison with their liquid-phase reactions with trichloroacetate ion or hexachloroacetone and base

Abstract

1-Unsubstituted imidazoles and chloroform at 550 °C in a flow system give mainly 5-chloropyrimidines, together with 4-chloropyrimidines and chloropyrazines. The effects of methyl substituents on the ratio of products is considered. The liquid-phase reactions of 2-methyl- and 2,4,5-trimethyl-imidazole under conditions in which dichlorocarbene is said to be formed in basic or neutral conditions were studied, and compared with the gas-phase reactions with chloroform.