Hydrochloric Acid → 1,2-Bis(3,4-dimethoxyphenyl)ethanone

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Reaction Steps

Powdered anhydrous aluminum chloride (0.78 g) was slowly added to a stirred mixture of 1,2-dimethoxybenzene (0.64 g, 4.66 mmol) and 3,4-dimethoxyphenylacetyl chloride (1.0 g, 4.66 mmol) in 10 mL freshly distilled dry dichloromethane. An exothermic reaction occurred. The orange solution became brown as the mixture refluxed. The reaction mixture was heated to reflux for an additional 2 h and then allowed to cool to room temperature. The cooled solution was poured into a mixture containing of 5 g crushed ice and 5.5 mL 7.5 N HCl. The organic phase was separated and the aqueous phase was extracted three times with 10 mL dichloromethane. The combined dichloromethane extract was dried (Na2SO4), filtered, and evaporated to give a white solid, which was crystallized from ethanol to give pure white needles of 11a in 98% yield; mp 105-107° C. (lit.30 mp 104-106° C.); 1H NMR δ 3.85 (s, 6H), 3.91 (s, 3H), 3.94 (s, 3H), 4.18 (s, 2H), 6.81 (m, 2H), 6.91 (m, 2H), 7.56 (d, 1H, J=2.0), 7.66 (dd, 1H, J=8.4,2.0); 13C NMR δ 45.2, 56.3, 56.4, 56.5, 110.4, 111.1, 111.8, 112.8, 121.3, 121.9, 123.9, 127.9, 130.2, 148.4, 149.5, 153.8, 197.0.

Provenance & Evidence