Carbon Dioxide → Cyclohexyl isocyanate

Participants

Reaction Conditions

Reaction Steps

Carbon dioxide was added subsurface to a dichloromethane (20 mL) solution containing cyclohexylamine (0.02 mol, 1.98 g), triethylamine (0.06 mol, 6.0 g) at -10° C. (ice and salt bath) for 30 min at a pressure of 0 psig. The reaction mixture was transferred via cannula all at once under carbon dioxide to the precooled solution of phosphorus oxychloride (0.02 mol, 3.2 g) in 20 mL dichloromethane. After stirring ca. 30 min at -10° C. a white ppt formed. The ppt was filtered off and the filtrate concentrated in vacuo. The residue was extracted with 3×20 mL diethyl ether. The ether layers (light yellow) were 20 concentrated and the residue was distilled under vacuum collecting product, cyclohexyl isocyanate, at 31°-33° C. (1.45 g, 58%) of 97% purity as judged by GC. IR (neat) 2261 cm-1. 1H NMR (CDCl3) δ 3.44-3.39 (m, 1H), 1.90-1.85 (m, 2H), 1.72-1.68 (m, 2H), 1.50-1.41 (m, 2H), 1.33-1.20 (m, 3H) ppm.

Provenance & Evidence