Butyric Acid → 4-(3-Trifluoromethylphenyl)-7-methoxy-1-tetralone

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Reaction Steps

Ethyl 3-(3-trifluoromethylphenyl)-3-(4-methoxyphenyl)propionate was converted to 4-(3-trifluoromethylphenyl)-4-(4-methoxyphenyl) butanoic acid by standard methods, viz. reduction of the propionate ester to the propanol (93%) tosylation (81%), conversion to the butyronitrile (67%) and hydrolysis to the butanoic acid (85%), which was obtained as a pale yellow oil. This oil (10 g) was stirred overnight at room temperature in a solution of methanesulphonic acid (100 g) and phosphorus pentoxide (21 g). The mixture was poured onto ice, extracted with ether, the extracts washed with dilute sodium hydroxide, dried (MgSO4) and filtered through a short column of alumina. Removal of the ether gave 4-(3-trifluoromethylphenyl)-7-methoxy-1-tetralone as a pale yellow oil (7.65 g, 81%).

Provenance & Evidence