Methanol → 1-isopropyl-3-methyl-6-(pyridazin-4-yl)-1H-indole-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a 100 ml round bottom flask was added methyl 1-isopropyl-3-methyl-6-(pyridazin-4-yl)-1H-indole-4-carboxylate (74.0 mg, 0.239 mmol), Methanol (1595 μl), Tetrahydrofuran (THF) (3189 μl) and a magnetic stir bar. To the same was added lithium hydroxide, H2O (30.1 mg, 0.718 mmol) and the mixture was stirred at 55° C. Reaction progress was monitored by LCMS. LCMS (weekend) showed 50% conversion. To the reaction mixture was added lithium hydroxide, H2O (20.08 mg, 0.478 mmol) The reaction was continued to stir and heated to 55° C. After complete conversion the reaction solvent was removed and the remaining residue dissolved with water (1.5 ml). The aqueous solution was made acidic drop wise with 1N HCl until precipitation was complete. The solid was collected by vacuum filtration and washed with water (5 ml). The solid was dried under vacuum open to the air overnight. The product, 1-isopropyl-3-methyl-6-(pyridazin-4-yl)-1H-indole-4-carboxylic acid (68 mg, 0.228 mmol, 95% yield), was obtained as a brown solid. 1H NMR (400 MHz, DMSO-δ6) δ 9.71-9.83 (m, 1H), 9.23 (dd, J=1.26, 5.56 Hz, 1H), 8.32 (s, 1H), 8.11 (dd, J=2.65, 5.43 Hz, 1H), 7.86 (s, 1H), 7.58 (s, 1H), 4.90-5.09 (m, 1H), 2.34 (s, 3H), 1.47 (d, J=6.82 Hz, 6H). MS(ES) [M+H]+ 296.2.

Provenance & Evidence