Studies on Benzoheterocyclic Derivatives. XV. Synthesis of Benzofuran Derivatives. (3)

With the expectation of analgesic activity, 3-substituted amino- or aminomethyl-2, 3-dihydrobenzofuran derivatives were synthesized, with special emphasis on the 5-position, corresponding to meta position of the phenethylamine skeleton. The intermediate 3-bromo-2, 2-dimethyl-5-methoxy-2, 3-dihydrobenzofuran had a high reactivity and showed various interesting characteristics. Cyanation of this bromo compound was difficult but 3-cyano-2, 2-dimethyl-5-methoxy-2, 3-dihydrobenzofuran was obtained in a good yield by the use of copper cyanide. This type of 3-cyano-2, 3-dihydrobenzofuran is a new compound. Analgesic effect of these benzofuran derivatives was equal to or less than that of aminopyrine.