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

Temperature

40 °C

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).

1. customA 2 L three-neck round bottom flask equipped with a condenser, mechanical stirrer, nitrogen inlet
2. temperatureThe resulting suspension was warmed
3. customthe reaction
4. temperatureto reflux
5. temperatureHeating
6. temperatureto maintain
7. temperaturereflux for 14 hours
8. temperatureThe reaction mixture was then cooled slightly
9. customexcess ethanol was removed by rotary evaporation, water (1 L) and diethyl ether (600 mL)
10. additionwere added
11. customThe organic phase was separated
12. washwashed several times with water (6×500 mL)
13. dry with materialdried over anhydrous magnesium sulfate
14. customEvaporation of the diethyl ether

ORD record

ord-d75bdfa57788419c826e63685caabb81

Source dataset

uspto-grants-2002_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06479424B1