p-Toluenesulfonic acid → 4-Methoxy-2,2-dimethyl-1,3-benzodioxole

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Reaction Steps

3-methoxycatechol (25 g) was dissolved in benzene, mixed with dimethoxyacetal (35 ml) and a catalytic amount of tosylic acid, and then, heat-refluxed for 6 hours. The resultant was allowed to stand for cooling, alkalified by adding an aqueous sodium hydroxide solution, and extracted with ether. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over manganese sulfate, and evaporated under reduced pressure for removing the solvent. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1) to give Compound IIbv-a (19.4 g, 60.5%) as a white solid.

Provenance & Evidence