Formaldehyde → N-methyl-N-(3,5-dimethylcyclohexyl)-N-(4-nitrobenzyl)amine

Participants

Reaction Steps

In 1,2-dichloroethane (70 ml) were suspended p-nitro-benzylamine hydrochloride (3.8 g), 3,5-dimethylcyclo-hexanone (2.5 g) and triethylamine (2.8 ml). Under ice-cooling, to the mixture was added sodium triacetoxy boron hydride (5.9 g). Under nitrogen atmosphere, the mixture was stirred at room temperature over night. Under ice-cooling, to the mixture were added 37% formalin(1.8 ml) and sodium triacetoxy boron hydride (5.9 g). Under nitrogen atmosphere, the mixture was stirred at room temperature over night. The solvent was evaporated, and the residue was neutralized with sodium hydroxide. The mixture was extracted with ethyl acetate. The organic layer was washed with water and saturated sodium chloride solution, and dried with anhydrous magnesium sulfate. Under reduced pressure, the solvent was evaporated, and the residue was purified with silica gel column (ethyl acetate/hexane) to give 3 isomers of N-methyl-N-(3,5-dimethylcyclohexyl)-N-(4-nitrobenzyl)-amine (4.3 g; (31-a), 0.7 g; (31-b), 0.2 g; (31-c)) as each yellow oil. 31-a: 1H-NMR(δ ppm, CDCl3): 0.53-0.74 (1H, m), 0.84 (3H, s), 0.87 (3H, s), 0.93-1.07 (2H, m), 1.73-1.99 (5H, m), 2.06 (3H, s), 2.49 (1H, t, J=2.8 Hz), 3.60 (2H, s), 7.50 (2H, d, J=8.8 Hz), 8.17 (2H, d, J=8.8 Hz). IR(neat) ν: 2949, 1606, 1521 cm−1.

Provenance & Evidence