Tetrahydrofuran → 4-Bromo-6-(cyclohexylmethyl)-1,2,3,5-tetrahydro-s-indacene

Participants

Reaction Steps

To a solution of 39.5 g (0.114 mol) of 4-bromo-2-(cyclohexylmethyl)-3,5,6,7-tetrahydro-s-indacen-1(2H)-one in 170 ml of THF 15.2 g (0.398 mol) of NaBH4 was added. Further on, 340 ml of methanol was added dropwise by vigorous stirring for 2 h. The resulting mixture was stirred for 12 h at room temperature, evaporated to a volume of ca. 300 ml, and then 100 ml of 3.0 M HCl was added. The product was extracted with 3×200 ml of dichloromethane. The organic extract was dried over Na2SO4 and then evaporated to dryness. A solution of the residue and 1.4 g of TsOH in 800 ml of toluene was refluxed for 30 min with Dean-Stark head. The obtained solution was passed through short layer (50 mm) of silica gel 60 (40-63 um), the filtrate was evaporated to dryness. This procedure gave 34.7 g (93%) of the title product which was further used without an additional purification.

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