L-(+)-Cysteine → 2-(7-(3-Cyano-4-isopropoxybenzyloxy)-9-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetic Acid

Participants

Reaction Conditions

Reaction Steps

To a pre-cooled flask containing tert-butyl 2-(7-(3-cyano-4-isopropoxybenzyloxy)-9-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetate (0.308 g, 0.649 mmol) was added a pre-cooled solution of D/L-2-Amino-3-mercaptopropanoic acid (0.079 g, 0.649 mmol) in TFA (6.49 mL, 0.649 mmol) at 0° C. After stirring for 3 h at 0° C., ice-cold water (65 mL) was added. The resulting suspension was diluted with Et2O (130 mL). The organic layer was separated, washed with water (2×30 mL), brine (30 mL), and dried over MgSO4. The solvent was coevaporated with toluene (25 mL) in vacuo at 25° C. The residue was coevaporated with toluene (20 mL) again to give an oil. The oil was dissolved in DCM (5 mL) and coevaporated with hexanes (25 mL) to give the title compound as a grey solid (0.299 g). LCMS m/z=419.4 [M+H]+; 1H NMR (400 MHz, DMSO-d6) δ ppm 1.32 (d, J=6.06 Hz, 6H), 2.16 (s, 3H), 2.19-2.29 (m, 1H), 2.47 (d, J=6.69 Hz, 1H), 2.70-2.82 (m, 2H), 3.54-3.65 (m, 1H), 3.92 (m, 1H), 4.03 (dt, J=8.05, 1.91 Hz, 1H), 4.79 (dt, J=12.13, 6.06 Hz, 1H), 5.04 (s, 2H), 6.74 (dd, J=8.72, 2.40 Hz, 1H), 7.00 (d, J=2.40 Hz, 1H), 7.13 (d, J=8.72 Hz, 1H), 7.28 (d, J=8.84 Hz, 1H), 7.72 (dd, J=8.78, 2.21 Hz, 1H), 7.78 (d, J=2.15 Hz, 1H), 12.27 (bs, 1H).

Provenance & Evidence