Bromination of 3-amino- and 3-dimethylamino-pyridine
Abstract
3-Dimethylaminopyridine and 2,4,4,6-tetrabromocyclohexa-2,5-dienone react to give exclusively 2-bromo-5-dimethylaminopyridine, but 3-aminopyridine gives a mixture of 3-amino-2-bromo- and 3-amino-2,6-dibromo-pyridine. 2-Amino- and 2-dimethylamino-pyridine and 2-aminopyrimidine are attacked at the 5-position. Convenient syntheses of 3-dimethylaminopyridine and 2-amino-5-dimethylaminopyridine are described.