Methanol → 6-cyano-3-methyl-1-(1-methylethyl)-1H-indole-4-carboxylic acid

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Reaction Steps

To a 50 ml round bottom was added methyl 6-cyano-3-methyl-1-(1-methylethyl)-1H-indole-4-carboxylate (230 mg, 0.897 mmol), followed by methanol (1 mL) and THF (1 mL). To the solution was added 3M NaOH (0.449 mL, 2.69 mmol). The reaction stirred at rt for 20 h. The reaction was evaporated and treated with acidic water to pH 5. A brown solid crashed out and was collected by filtration. The solid was an impurity. The pH of the liquid was adjusted to 3 and the liquid was evaporated leaving a residue. Trituration of the residue with water, followed by filtration yielded 6-cyano-3-methyl-1-(1-methylethyl)-1H-indole-4-carboxylic acid (155 mg, 0.576 mmol, 64.2% yield) as a yellow solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 13.16 (br. s., 1H) 8.33 (s, 1H) 7.78 (s, 1H) 7.66 (s, 1H) 4.81-4.98 (m, 1H) 2.33 (s, 4H) 1.45 (d, J=6.57 Hz, 6H). MS(ES) [M+H]+ 243.3.

Provenance & Evidence