Hydrochloric Acid → 2-Methyl-7-phenylindene

Participants

Reaction Conditions

Reaction Steps

50 g (0,226 mol) of 2 were dissolved in 450 cm3 of THF/MeOH (2:1) and, while stirring at 0° C., 12.8 g (0.34 mol) of sodium borohydride were added a little at a time. The mixture was stirred for a further 18 hours. The reaction mixture was poured onto ice, acidified with concentrated HCl to a pH of 1 and extracted a number of times with Et2O. The combined organic phases were washed with saturated aqueous NaHCO3 solution and NaCl solution and then dried (MgSO4). The solvent was removed under reduced pressure and the crude product was, without further purification, taken up in 1 dm3 of toluene, admixed with 2 g of p-toluenesulfonic acid and heated under reflux for 2 hours. The reaction mixture was washed with 200 cm3 of saturated aqueous NaHCO3 solution and the solvent was removed under reduced pressure. The crude product was purified by filtration through 500 g of silica gel (hexane/CH2Cl2). This gave 42 g (90%) of 3 as a colorless oil.

Provenance & Evidence