Isobutyl chloroformate → HCID 59375156, compound

Participants

Reaction Steps

A solution of 8-carbamoyl-5-(2,6-difluorophenyl)-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylic acid (Intermediate 23-3, 720 mg, 1.944 mmol) and TEA (1.084 mL, 7.78 mmol) in THF (5 mL) was treated with isobutyl chloroformate (266 mg, 1.944 mmol) at 0° C. After stirring for 10 min, a solution of N,O-dimethylhydroxylamine hydrochloric acid salt (190 mg, 1.944 mmol) in THF (2 mL) and water (0.5 mL) was added. The mixture was stirred for 30 min, then diluted with DCM, washed with NaHCO3 (aq) and water, and dried and concentrated. The residue was purified by column chromatography (eluting with EtOAc) to provide 5-(2,6-difluorophenyl)-N2-methoxy-N2-methyl-2,3,4,9-tetrahydro-1H-carbazole-2,8-dicarboxamide as a white solid (802 mg, 93%). 1H NMR (400 MHz, chloroform-d) ε1.70-1.82 (m, 1H) 1.90-1.99 (m, 1H) 2.19-2.25 (m, 2H) 2.32-2.42 (m, 1H) 2.84-2.92 (m, 1H) 3.05-3.19 (m, 1H) 3.23 (s, 3H) 3.70 (s, 3H) 6.98-7.06 (m, 3H) 7.35-7.42 (m, 2H) 10.10 (s, 1H). Mass spectrum m/z 414.2 (M+H)+.

Provenance & Evidence