Methyl chloroformate → 3-Chloro-4-hydroxy-1-(methoxycarbonyl)-2,3-dihydro-1H-benzo[f]indole

Participants

Reaction Conditions

Reaction Steps

A solution of 28 (11 mg, 29.1 μmol) was treated with 1.0 mL of 3.6 N HCl/EtOAc and the resulting solution was stirred for 30 min at 25° C. The solvent was removed by a stream of N2 and the residual salt was dried under vacuum. This salt was suspended in 0.6 mL of anhydrous THF and treated with NaHCO3 (5.4 mg, 64.1 μmol, 2.2 equiv) and ClCO2CH3 (4.5 μL, 58.2 μmol, 2.0 equiv) and the mixture was stirred for 3 h at 25° C. Upon completion, the reaction mixture was diluted with 10 mL of H2O extracted with EtOAc (3×10 mL), dried (Na2SO4) and concentrated in vacuo. Flash chromatography (SiO2, 1.5×15 cm, 0-40% EtOAc/hexane gradient) provided pure 32 (5.5 mg, 65%) as a white solid: 1H NMR (CDCl3, 400 MHz ) δ7.86 (d, J=8.2 Hz, 1H), 7.86 (br s, 1H), 7.73 (d, J=8.0 Hz, 1H), 7.42 (m, 1H), 7.35 (m, 1H), 5.80 (s, 1H), 4.11 (m, 2H), 4.01-3.87 (m, 5H), 3.63 (app t, J=9.4 Hz, 1H); IR (film) νmax3379, 2956, 1673, 1435, 1372, 1283, 1218 cm−1; FABHRMS (NBA/NaI) m/z 291.0656 (M+, C15H14ClNO3 requires 291.0662).

Provenance & Evidence