Methanol → 6-Methyl-4-phenyl-1,2,3,5-tetrahydro-s-indacene

Participants

Reaction Conditions

Reaction Steps

9.6 g (24.4 mmol) of 4-phenyl-2-methyl-3,5,6,7-tetrahydro-s-indacen-1(2H)-one (2a) and 2.10 g (55 mmol) of sodium borohydride in 40 ml of toluene were placed in a reaction vessel. The solution was heated to 50° C. and 7 ml of methanol was added slowly and the reaction mixture was stirred at 50° C. for 3 hours. After cooling to room temperature 12 ml of water and 40 ml of 1 N sulfuric acid were added and the mixture was stirred for 30 minutes. After phase separation the water phase was extracted with toluene. Organic phase was evaporated and the residue was taken up in 100 ml of toluene and mixed with 100 mg of p-toluenesulfonic acid. Water was distilled off from this reaction mixture by refluxing for 2 hours on a water separator until reaction was complete. The reaction mixture was washed once with 100 ml of saturated sodium hydrogen carbonate solution and dried over magnesium sulfate. After removal of the solvent, the residue was dried in an oil pump vacuum. This gave 11.5 g of brawn oil. The crude product was purified by column chromatography (200 g of silica gel, 1 l of heptane: diethylether=9:1).

Provenance & Evidence