Benzylamine → N,N-dimethyl-N'-benzyl-1,2-cyclohexanediamine

Participants

Reaction Steps

A solution of trans-2-dimethylaminocyclohexanol (58 g., 0.405 mole) prepared in Part A in 80 ml. of THF is added during 10 min. to a suspension of NaH (17.05 g., 0.405 mole of 57% dispersion in mineral oil) in 240 ml. of THF and the mixture is refluxed for 3 hours. It is cooled to 10° and methanesulfonyl chloride (46.39 g., 0.405 mole) added dropwise during 30 min., keeping the temperature below 10°. Benzylamine (86.79 g., 0.81 mole) is then added during 5 min., the solvent evaporated, and heating continued at 95° for 16 hr. NaOH (500 ml. of 20% solution) is added and the mixture heated at 95° for 1 hr., cooled, and extracted with ether (5 × 100 ml.). The ether solution is extracted with 10% HCl (6 × 100 ml.) and backwashed once with ether (discard). The acid extract is cooled, basified with 20% NaOH, and extracted with ether. The ether solution is washed with H2O, saturated salt solution, dried (MgSO4) and evaporated. Distillation at 0.4 mm gives 61 g. (65% yield) of N,N-dimethyl-N'-benzyl-1,2-cyclohexanediamine, b.p. 112°. It is identical by tlc to the sample prepared by the reaction of benzylamine with trans-2-chloro-1-dimethylaminocyclohexane (Procedure III).

Provenance & Evidence