Synthesis of N-(p-aminobenzoyl)-1,2,3,4-tetrahydro-4,8-dimethylquinoline

This investigation was to study the synthetic rcute of N- (p- Aminobenzoyl) – 1, 2, 3, 4-tetrahydro-4, 8-dimethylquinoline which was expected to possess anticonvulsant activity. The synthesis of N- (p-Aminobenzoyl) - 1, 2, 3, 4- tetrahydro-4, 8-dimethylquinoline proceeded through 9 steps. (1) 4-Chlorobutyl benzoate was prepared from the reaction of benzoyl chloride with tetrahydrofuran in the presence of zinc chloride. (2) 4- [N- (0- Toluidino)] butyl benzoate hydrochloride salt was prepared from the reaction of 4-Chlorobutyl benzoate and 0-toluidine at 125° - 130° c. (3) 4- [N- (0- Toluidino)] butanol was prepared from the alkaline hydrolysis of 4-[N-(o-Toluidino)] butyl benzoate hydrochloride salt. (4) N- (4-Hydroxybutyl) -N- (0-tolyl) formic acid. (5) N-(4-Chlorobutyl) -N- (0-tolyl) formamide was prepared from the reaction of N- (4-H Hydroxybutyl) -N- (0-tolyl) formamide with thionyl chloride. (6) N-Formyl -1, 2, 3, 4-tetrahydeo-4, 8-dimethylquinoline was prepared from the intramolecular cyclization of N-Chlorobutyl)-N- (0-tolyl) formamide. (7) 1, 2, 3, 4- Tetrahydro-4,8- dimethyIquinoline was prepared from the alkaline hydrolysis of N-Fromy 1-1, 2, 3, 4-tetrahydro-4, 8-dimethyl–quinoline. (8) N- (p-Nitro-benzoyl) - 1, 2, 3, 4, -tetrahydro-4, 8-dimethyIquinoline was prepared from the reaction of 1, 2, 3, 4 - Tetrahydro-4, 8- dimethyIquinoline with p-nitrobenzoyl chloride. And (9) N- (p-Aminobenzoyl) - 1, 2, 3, 4 - tetrahydro-4, 8-dimethyl – quinoline was prepared from the catalytic hydrogenation of N- (p-Nitrobenzoyl) -1, 2, 3, 4, -tetrahydro-4, 8- dimethyIquinoline by the used of palladium / activated carbon as a catalyst. The final product is a mixture of two enantiomers. The NMR spectroscopic data indicate that each enantiomer is composed of four conformers. The structures of the synthesized compounds were confirmed by IR, proton-l and carbon-13 NMR, and MS techniques.