Abstract
The quaternary salt methiodide of the N-Mannich bases of theophylline has direct C-alkylating ability and, although the tertiary salts had no alkylating ability, the quaternary salt methiodide effected transaminomethylation. Reaction of indole and N-Mannich bases of benzimidazole afforded compounds (VI and III), in which aminomethyl group had been exchanged, and alkylated products. Detailed examination of the said reaction showed that transaminomethylation (a) occurred as the first step and, as a second step, the compounds (VI and VIII), formed by the said exchange reaction, underwent further reaction (b) to form 1-(3-indolylmethyl) benzimidazole (IX). The formation of (IX) was proved to be not the C-alkylation of the N-Mannich bases but N-alkylation of the Mannich base (VI) of indole by benzimidazole.
