| abstract |
The invention concerns a process for preparing phthalides of general formula (I), in which R?1, R2, R3 and R4¿, independently of each other, designate hydrogen, C¿1?-C4 alkyl or C1-C4 alkoxy, by the hydrogenation of phthalic acid anhydrides of general formula (II), in which the groups R?1, R2, R3 and R4¿ have the above meanings, by means of hydrogenating catalysts. Hydrogenation is carried out by means of nickel catalysts doped with metals of the first, sixth and/or seventh subgroup of the periodic system. |