(1-Cyanocyclohexyl)acetic acid → Gabapentin

Participants

Reaction Steps

One gram of 10% rhodium on carbon, containing 1% palladium, (Pearlman, W. M., Tetrahedron Letters, pages 1663-1664 (1967)) is slurried in 30 ml methanol and reduced under hydrogen in a Parr shaker. 1-Cyanocyclohexaneacetic acid (16.7 g, 0.1 mol) is dissolved in 40 ml methanol and combined with the reduced catalyst. The mixture is placed under 50 pounds per square inch gauge (psig) hydrogen and shaken for two hours at room temperature. The catalyst is removed by filtration, and the filtrate is condensed to a volume of 25 ml by vacuum distillation. Isopropanol, 100 ml, is added and an additional 25 to 50 ml of solvent is removed by vacuum distillation. The resultant slurry is cooled at 0° to 5° C. for 24 hours and filtered and dried to give 13.65 g (79% of theory) of 1-(aminomethyl)-cyclohexaneacetic acid; mp 162°-163° C.

Provenance & Evidence