Synthesis
To a mechanically stirred solution of AlCl3 (103.60 g, 0.779 mol) in
THF (900 ml), at 0 ºC, LiAlH4 (59.80 g, 1.575 mol) was added
cautiously, in portions. Temperature was maintained below 10 ºC. A
solution of 2-(1-Hydroxycyclohexyl)-2-(4-methoxyphenyl) acetonitrile(130.0 g, 0.530 mol) in THF (500 ml) was
added drop-wise over a period of 1.5 hours. The reaction mixture was
then brought to room temperature and stirred for 30 minutes. The
reaction mixture was again cooled in an ice-salt bath. The reaction was quenched with
ethyl acetate (60 ml) maintaining the temperature below 10 ºC. The reaction mixture was
then transferred to a beaker, cooled externally in an ice-salt bath and treated very
cautiously with 25% aq. NaOH solution (360 ml) with mechanical stirring. (After addition
of about 50 ml 25% aq. NaOH solution, a hard solid was formed, cooling was removed and
the contents were stirred manually during the addition of remaining NaOH solution). The
solid was loosened at room temperature, which was further stirred for 1 hour. A bright
white solid appeared. The solid was filtered off, washed thoroughly with ethyl acetate. The
filtrate was concentrated in vacuo and combined with the above washings, washed with
brine, dried over anhydrous Na2SO4, filtered and ethyl acetate removed under reduced
pressure to obtain aminoalcohol 38 as a thick yellow oil (129.4 g).