Boron tribromide → ethyl 2-(7-hydroxy-8-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetate

Participants

Reaction Steps

To a stirred solution of ethyl 2-(7-methoxy-8-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetate (320 mg, 1.114 mmol) in anhydrous DCM (8 mL) was added a 1M solution of boron tribromide in DCM (3341 μL, 3.34 mmol) at 0° C. under nitrogen protection. The reaction mixture was stirred at this temperature for 1 h, neutralized by addition of saturated NaHCO3 solution. The organic layer was separated and washed with water and dried over anhydrous Na2SO4. The solvent was evaporated, and the residue was purified by column chromatography to give the title compound (200 mg) as a light yellow oil. LCMS m/z=274.3 [M+H]+; 1H NMR (400 MHz, CDCl3) δ ppm 1.32 (t, J=7.1 Hz, 3H), 2.25-2.32 (m, 1H), 2.40 (s, 3H), 2.58 (dd, J=16.0, 8.5 Hz, 1H), 2.82-2.90 (m, 2H), 3.73-3.80 (m, 1H), 3.95-4.02 (m, 1H), 4.05-4.13 (m, 1H), 4.20-4.27 (m, 2H), 4.58 (s, 1H), 6.09 (s, 1H), 6.69 (d, J=8.5 Hz, 1H), 6.95 (d, J=8.5 Hz, 1H).

Provenance & Evidence