J. Streef, H. J. Hertog, H. Plas
Jul 1, 1985
Citations
0
Influential Citations
9
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Reactions of 2,6-dichloro-3-phenyl-, 2,6-dibromo-3-phenyl-, 2,6-dichloro-3-dimethylamino- and 2,6-dibromo-3-dimethylaminopyridine with potassium amide in liquid ammonia were investigated. Whereas 2,6-dichloro-3-phenylpyridine yields 4-amino-2-benzylpyrimidine, from 2,6-dibromo-3-phenylpyridine as a product of a novel ring fission 2-amino-l-cyano-l-phenyl-but-l-en-3-yne was isolated, together with 4-amino-6-bromo-3-phenylpyridine and 2,6-diamino-3-phenylpyridine. It was shown that neither 2-amino-6-bromo-3-phenyl- nor 6-amino-2-bromo-3-phenylpyridine are intermediates in the formation of the 2,6-diamino derivative, as these bromo compounds are transformed in the basic medium into 1,3-dicyano-l-phenylpropene. From both 2,6-di-chloro-3-dimethylamino- and 2,6-dibromo-3-dimethylaminopyridine mixtures are obtained from which only 2-amino-l-cyano-l-dimethylamino-but-l-en-3-yne and 4-amino-6-halogeno-3-dimethylaminopyridine were isolated. Mechanisms for the reactions studied are proposed, i.e. a SN(ANRORC) mechanism for the aminodebromination of 2,6-dibromo-3-phenylpyridine into the corresponding 2,6-diamino compound.