N-Methylcyclohexylamine → HCID 19961906, compound

Participants

Reaction Steps

To a solution of 2,5-dioxo-1-propyl-1,4-benzodiazepine (see Example 8) (10.0 g, 0.046 mol) in dichloromethane (200 ml) was added phosphorus pentachloride (11.5 g, 0.055 mol) in dichloromethane (400 ml) over 30 minutes. The reaction mixture was stirred at room temperature for 2 h then the solvent was removed under vacuum and the resulting oil was dried under high vacuum. The oil was redissolved in dichloromethane (200 ml) and a solution of N-methylcyclohexylamine (15.6 g, 0.138 mol) in dichloromethane (125 ml) was added dropwise. When the addition was complete, the reaction mixture was allowed to stir for 18 hours. The solution was washed with saturated sodium hydrogen carbonate solution (100 ml), and the aqueous layer was reextracted with dichloromethane (2×100 ml). The combined organic layers were washed with brine (100 ml), dried (sodium sulphate), filtered and concentrated in vacuo. The residue was dissolved in a small amount of dichloromethane and purified by flash column chromatography, eluted with 2% methanol/0.5% 0.88 ammonia solution/dichloromethane (3 litres) then 5% methanol/0.5% 0.88 ammonia solution/dichloromethane. Yield=15.8 g (quantitative), as a brown oil. 1H NMR (DMSO)δ0.68 (3H, t, J=7.3 Hz), 1.84-2.04 (3H, m), 2.72 (3H, s), 3.40 (1H, d, J=12.2 Hz), 3.54 (1H, m), 3.88 (1H, d, J= 12.2 Hz), 4.22 (1H, m), 7.34 (1H, m), 7.50 (1H, d, J=7.43 Hz), 7.60 (2H, m).

Provenance & Evidence