Ammonia → N,N-Didesmethylvenlafaxine

Participants

Reaction Steps

The reactor was charged with 25.0 g of Raney-Ni (Kawaken, Grace 2400, 2724, Degussa B111W, 112W), and 250 ml of MeOH and 25 ml of an ammonia solution (25% NH3) were added. To the mixture was added 50 g of 1-[cyano(4-methoxyphenyl)methyl]cyclohexanol, followed by 250 ml of MeOH. The reactor was settled and purged with N2 gas two or three times. After fully purged with N2, the reactor was purged with H2 gas two or three times. Internal pressure of the reactor was adjusted to 60 psi and the reaction mixture was stirred. After 20 to 30 hours of reaction at room temperature (about 10 to 20° C.), in-process analysis of a sample of mixture was made. After the reaction was completed, Ra—Ni was removed by filtration with a celite pad. The filtrate was distilled under reduced pressure until all of the solvent was evaporated, and 200 ml of isopropyl alcohol and 400 ml of ethyl acetate were added to the residue oil to dissolve the resulting product to give a clear or a little hazy solution. To the solution was added 10 ml of acetic acid dropwise, and an exothermic reaction began with some fumes given off. After about 10 to 20 minutes of adding all of the acetic acid, a solid began to form. The solution was stirred for about one hour, filtered and washed with ethyl acetate to give the desired product, 1-[2-amino-1-(4-methoxyphenyl)ethyl]-cyclohexanol, 44.2 g (yield 70%, purity 99%).

Provenance & Evidence