Dimethylformamide → Methyl 1-(4-nitrophenyl)cyclobutylcarbamate

Participants

Reaction Steps

A drop of DMF and oxalyl chloride (0.283 mL, 3.30 mmol) was added to a stirred solution of 1-(4-nitrophenyl)cyclobutanecarboxylic acid (503 mg, 2.27 mmol) in DCM (7 mL) under a nitrogen atmosphere and the resulting mixture was stirred for 25 minutes at room temperature. The volatiles were removed in vacuo and the residue was dissolved in acetone (4.50 mL). A solution of sodium azide (400 mg, 5.23 mmol) in water (4.50 mL) was added with the temperature maintained below 0° C. After stirring for 30 minutes, the mixture was diluted with chloroform and washed with cold water and saturated aqueous NaCl. The organics were dried with Na2SO4 and concentrated carefully. Toluene (10.0 mL) was added and the resulting solution was heated at 80° C. for 1 hour. MeOH (10 mL) was added and the resulting mixture heated at 60° C. for 1.5 hours under a nitrogen atmosphere. The volatiles were evaporated under reduced pressure then the residue adsorbed on silica gel and purified using silica gel column chromatography (CombiFlash Rf, SiO2 cartridge, 0-20% EtOAc in cyclohexane) to give the title compound A118 (404 mg, 71%); 1H NMR (300 MHz, CDCl3): δ 8.17 (d, J=9.0 Hz, 2H), 7.59 (d, J=8.9 Hz, 2H), 5.74 (br s, 1H), 3.57 (s, 3H), 2.52 (m, 4H), 2.15 (m, 1H), 1.92 (m, 1H); LCMS-B: rt 6.55 min; m/z 251.3 [M+H]+.

Provenance & Evidence