Hydrochloric Acid → 1,3-Benzodioxole, 5-(chloromethyl)-

Participants

Reaction Steps

A typical process for preparing piperonal from 1,2-methylenedioxybenzene has been reported by P. P. Shorygin et al. [J. Gen. Chem. (U.S.S.R.), 8,975 (1938)]. This is a two-step process. In the first step, 1,2-methylenedioxybenzene is reacted with formalin in petroleum benzine under the influence of hydrogen chloride gas and zinc chloride to form piperonyl chloride (with a 70-78% yield based on the amount of 1,2-methylenedioxybenzene having reacted). This is followed by the second step in which the piperonyl chloride is reacted with an equimolar amount of hexamine in 60% alcohol to give a 70-80% yield of piperonal. By E. D. Laskina et al. [Chemical Abstracts, 57,9714 (1962)], another process has been described in which 1,2-methelenedioxybenzene is reacted with formalin in the presence of a large excess of the sodium salt of m-nitrobenzenesulfonic acid, hydrogen chloride, and an aluminum catalyst to give a 42.4% yield of piperonal.

Provenance & Evidence