反应详情

t-Butyl methyl-(4-cyanocyclohexyl)carbamate (710 mg, 3 mmol) was dissolved in dichloromethane (20 ml) and trifluoroacetic acid (3 ml) was added. The solvent was evaporated after 2 hours, the residue was re-dissolved in a 4N HCl (3 ml) solution in dioxane and the solvent evaporated. Dichloromethane (30 ml) and NEt3 (2 ml) were added to the residue followed by a solution of [2,1,3]-benzoxadiazole-5-carbonylchloride (548 mg, 3 mmol) in dichloromethane (10 ml). After stirring the mixture for 1 hour at room temperature, the organic phase was washed with 1N HCl and conc. NaHCO3 solution, dried over magnesium sulfate, and concentrated under vacuum. The material was purified on a silica gel column eluting with ethyl acetate/chloroform (1:1) to give 170 mg of N-(cis-4-cyanocyclohexyl)-N-methyl-[2,1,3]-benzoxadiazole-5-carboxamide as a white solid and as the less polar isomer. Mp=222-223° C., 1H NMR (300 MHz, CDCl3, rotamers) δ 7.93 (d, 1H, J=9.0 Hz); 7.85 (s, 1H), 7.42 (d, J=9.0 Hz, 1H); 4.65-4.50 and 3.55-3.40 and 3.15-2.80 (m, 5H) and 2.20-1.30 ppm (m, 8H).

1. customThe solvent was evaporated after 2 hours
2. dissolutionthe residue was re-dissolved in a 4N HCl (3 ml) solution in dioxane
3. customthe solvent evaporated
4. additionDichloromethane (30 ml) and NEt3 (2 ml) were added to the residue
5. washthe organic phase was washed with 1N HCl and conc. NaHCO3 solution
6. dry with materialdried over magnesium sulfate
7. concentrationconcentrated under vacuum
8. customThe material was purified on a silica gel column
9. washeluting with ethyl acetate/chloroform (1:1)