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2′,5′-Dichloro-3,4-dimethoxybenzophenone was prepared analogously to 3,4,3′,4′-tetramethoxybenzophenone using veratrole (2.15 mL, 15 mmol), aluminum chloride (2.2 g, 16.5 mmol) and 2,5-dichlorobenzoyl chloride (1.9 mL, 15 mmol) with a reaction time of 3 hours at reflux. The crude product was purified by flash column chromatography (silica gel, 2.5% ethyl acetate/methylene chloride) to afford 3.88 g (83%) of the product as a white solid: mp 129–130° C.; 1H NMR (CDCl3) δ 7.65–7.56 (m, 1H), 7.41–7.12 (m, 4H), 6.89–6.81 (m, 1H), 3.96 (s, 3H), 3.94 (s, 3H); 13C NMR (CDCl3) δ 191.1, 154.4, 149.6, 137.9, 132.0, 130.5, 128.7, 128.0, 125.7, 110.2, 56.1, 56.0; Anal. Calcd for C15H12Cl2O3. Theoretical: C, 57.90; H, 3.89. Found: C, 57.58; H, 3.87.

1. customwith a reaction time of 3 hours
2. temperatureat reflux
3. customThe crude product was purified by flash column chromatography (silica gel, 2.5% ethyl acetate/methylene chloride)