| abstract |
Process for the preparation of phthalides of the general formula I in which R¹, R², R³ and R⁴ are independently hydrogen, C₁- to C₄-alkyl and C₁- to C₄-alkoxy, by reacting phthalic anhydrides of the general formula II in which the radicals R¹, R², R³ and R⁴ have the meanings given above, on hydrogenation catalysts at temperatures from 50 to 400 ° C. and pressures from 1 to 400 bar, by using hydrogenation catalysts essentially in the absence of Lewis acids. |