A method for the production of phthalaldehydic

摘要

Phthalaldehydic acid (I) is made by the hydrolysis of 1-trichloromethyl-2-dichloromethylbenzene (II) using a stoichiometric excess of water, opt. contg. HCl, in the absence of salts with catalytic activity, at temps. of 120-200 degrees C and autogenic pressures. In comparison with prior art processes, the conversion proceeds without the use of catalysts, does not give high exotherms, and allows easy sepn. of the reaction prods., and can be operated on an industrial scale with relatively simple appts. (I) is a useful intermediate for the prodn. of "Phthalazon" and other pharmaceutical prods.