Acylation and alkylation of 1,3-dimethoxybenzene in polyphosphoric acid

Abstract

Products of the reaction of 3-halo- and 3-ethoxypropionic acids with 1,3-dimethoxybenzene (4) in polyphosphoric acid have been shown to be 2′,4′-dimethoxy-3-(2,4-dimethoxyphenyl)-propiophenone (6) and 1,5-bis[3-(2,4-dimethoxyphenyl)-3-keto-propyl]-2,4-dimethoxybenzene (15) and these have been prepared by unambiguous syntheses. 2′,4′-Dimethoxy-3-ethoxypropiophenone (3a) and 2′,3,4′-trimethoxypropiophenone (3d) have been synthesized by the reaction of 3-chloro-2′,4′-dimethoxy- propiophenone (3c) with ethanol and methanol respectively.