5-Bromo-1-indanone → 5-bromo-2,3-dihydro-1H-inden-1-ol

Participants

Reaction Conditions

Reaction Steps

A 2 L three-neck round bottom flask equipped with a condenser, mechanical stirrer, nitrogen inlet and a thermometer was charged with 5-bromo-1-indanone (Aldrich 98%, 50.0 g, 0.24 mol) and ethanol (700 mL). The resulting suspension was warmed, with stirring, to 40° C. and sodium borohydride (18.2 g, 0.48 mol) was added incrementally over 20 minutes. A moderate exotherm ensued which brought the reaction to reflux. Heating was applied to maintain reflux for 14 hours. The reaction mixture was then cooled slightly, excess ethanol was removed by rotary evaporation, water (1 L) and diethyl ether (600 mL) were added. The organic phase was separated, washed several times with water (6×500 mL), and dried over anhydrous magnesium sulfate. Evaporation of the diethyl ether gave a quantitative yield of 5-bromo-1-indanol (50.5 g, 0.24 mol) crystals. 1HNMR (CD2Cl2, 500 MHz) δ7.39 (s, 1H); 7.35 (dd, JAB=1, 8 Hz, 1H); 7.26 (d, JAB=8 Hz, 1H); 5.17 (br s, 1H); 3.00 (m, 1H); 2.80 (p, J=8 Hz, 1H); 2.46 (m, 1H); 1.92 (m, 1H); 1.86 (s, 1H).

Provenance & Evidence