Reacción #323878

ord-cae0cf3dbb994694847a15f0c887352c

Ecuación de reacción

c1ccc2c(c1)OCO2
1,2-methylenedioxybenzene
C=O
formalin
Cl
hydrogen chloride
O=Cc1ccc2c(c1)OCO2
piperonal
c1ccc2c(c1)OCO2
1,2-methylenedioxybenzene
ClCc1ccc2c(c1)OCO2
piperonyl chloride
Rendimiento 70.0%

Condiciones de reacción

Condiciones detalladas
See reaction.notes.procedure_details.

Procedimiento

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.

Fuente

DOI: 10.6084/m9.figshare.5104873.v1Patente: US04157333uspto-grants-1979_06