Reactions of N-Alkyl-N-phenyl-1H-benzotriazole-1-methanamines with N-Vinylamides and N-Vinylcarbazole. A Convenient Synthesis of 4-(Dialkylamino)tetrahydroquinolines

Abstract

Reactions of N-alkyl-N-phenyl-1H-benzotriazole-1-methanamines 1 with N-vinyl-2-pyrrolidinone and with N-vinyl-N-methylacetamide give 4-(2-pyrrolidinon-1-yl)- and 4-(N-methylacetamido-N-yl)-1,2,3,4-tetrahydroquinolines (5 and 32), respectively. In a reaction with N-vinyl-2-pyrrolidinone, α-alkyl (11) and α-aryl (18) derivatives of 1 stereoselectively give cis-2,4-disubstituted tetrahydroquinolines 16 and 21, respectively. The 2-pyrrolidinon-1-yl and acetamido-N-yl substituents in the products are reduced with lithium aluminum hydride to the corresponding amino groups. Similar reactions of N-phenyl-1H-benzotriazole-1-methanamines 1 with 9-vinylcarbazole (40) lead to the corresponding 4-(carbazol-9-yl)-1,2,3,4-tetrahydroquinolines (41 and 42) and/or analogous 4-(benzotriazol-1-yl) or 4-(benzotriazol-2-yl) derivatives (37,38,43, and 44), depending on the nature of the starting material and the reaction conditions. By commencing with aniline derivatives in which the nitrogen atom is built into a heterocyclic system, this method allows for the addition of a another ring to the system, as exemplified by the conversion of phenothiazine into 46 and [3,1]-benzoxazine into 49, 52, and 53. © 1995, American Chemical Society. All rights reserved.