Конденсация хлоридов кислот с бензолами в присутствии хлористого алюминия.

SYNTHESIS: A suspension of 140 g anhydrous AlCl3 in 400 mL CH2Cl2 was treated with 100 g acetyl chloride.  This slurry was added to a vigorously stirred solution of 110 g p-dimethoxybenzene in 300 mL CH2Cl2.  Stirring was continued at ambient temperature for an additional 40 min, then all was poured into 1 L water and the phases separated.  The aqueous phase was extracted with 2x100 mL CH2Cl2 and the combined organic phases washed with 3x150 mL 5% NaOH.  These washes, after combination and acidification, were extracted with 3x75 mL CH2Cl2 and the extracts washed once with saturated NaHCO3. Re-moval of the solvent under vacuum provided 28.3 g of 2-hydroxy-5-methoxyaceto-phenone as yellow crystals which, on recrystallization from 2 volumes of boiling MeOH and air drying, provided 21.3 g of product with a mp of 49-49.5 deg C.  Ethyl-ation of this material serves as the starting point for the synthesis of 2CE-5ETO.  The CH2Cl2 fraction from the base wash, above, was stripped of solvent on the rotary evaporator to give a residual oil that, on distillation at 147-150 deg C at the water pump, provided 111.6 g of 2,5-dimethoxyacetophenone as an almost white oil.