ABSTRACT Animation of ring-polychlorinated pyrimidines by tertiary amines in phosphorus oxychloride or toluene takes place by a Hofmann type reaction. The π electron distriution as influenced by substituents causes orientation to the 2 position, and the yields of products depend on the base employed, reaction times, as well as substituents on the ring. The rate and regiospecificity of the substitution in the 2 position is significantly enhanced by the presence of a trifluoromethyl group in position 6, as compared with a methyl group and the presence or absence of a substituent at position 5. The base of choice for the formation of the best yields of ring-chlorinated pyrimidines with minimal by-product formation is tri-n-propylamine.
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