The starting p-substituted benzaldehydes (IV) were obtained by the Sommelet reaction [6] from the p-substituted benzyl chlorides (IIIa, b). Chloromethylation of the appropriate benzenes was carried out by the Blane method [8], and the optimum conditions for the preparation of (IIIa, b) in yields of 48 and 51.6% respectively, have been established (the yields reported in the literature [3, 12] are 20 and 7.2%).