418759-58-7

Preparation by treatment of 4-benzyloxy-5-methoxy2-nitro-acetophenone (m.p. 142–143°) with trifluoroacetic acid at r.t. for 14 h (89%).

General procedure for the synthesis of 1-(4-hydroxy-5-methoxy-2-nitrophenyl)ethanone from 1-(4-(benzyloxy)-5-methoxy-2-nitrophenyl)ethanone: first, 34.14 g (116 mmol) of 1-(4-(benzyloxy)-5-methoxy-2-nitrophenyl)ethanone was added to a 500 mL flask with stirring at room temperature with 300 mL of triarylboron trifluoroacetate. Upon completion of the reaction, 200 mL of aqueous sodium bicarbonate was added, followed by extraction with ethyl acetate (300 mL x 7). The organic phases were combined, dried with anhydrous magnesium sulfate, filtered and concentrated. The concentrate was recrystallized with 300 mL of ethyl acetate at 80°C, extracted and dried under vacuum to obtain the first crystal. The mother liquor was concentrated again, recrystallized with 20 mL of ethyl acetate at 80°C, filtered and vacuum dried to obtain the second crystal. The final yellow crystal 1-(4-hydroxy-5-methoxy-2-nitrophenyl)ethanone (Compound I3) was obtained in a yield of 20.9 g (98.9 mmol, 86% yield).

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