Bromination of 2-phenyl-1,2,3,4-tetrahydroquinolines

Bromination of 2-phenyltetrahydroquinolines derivatives was investigated. During the bromination of 2-phenyl-1,2,3,4-tetrahydroquinoline with bromine in chloroform or bromosuccinimide along with the formation of di- and tribrom derivatives the oxidation reaction occurs with the generation of quinoline structure. The interaction of 2-phenyl-1,2,3,4-tetrahydroquinoline with bromine in acetic acid leads to the formation of 6,8-dibromoderivative preserving the 1,2,3,4-tetrahydroquinoline ring. At the same time N-substituted 2-phenyl-1,2,3,4-tetrahydroquinoline is selectively brominated in various conditions with the formation of 6-monobromoderivative. By the method of X-ray diffraction analysis the molecular structure of 3,6,8-tribromo-2-phenylquinoline single crystals was determined.