Methyl chloroformate → 5-Chloro-2-methyl-4-nitro-indole-1-carboxylic acid methyl ester

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Reaction Steps

5-Chloro-2-methyl-4-nitro-1H-indole (1.62 g, 7.69 mmol) is dissolved under an atmosphere of argon in dry DMF (30 ml). After addition of a NaH suspension (60% in mineral oil, 369 mg, 9.22 mmol) the mixture is stirred for 1 hour at RT. Methyl chloroformate (0.72 ml, 9.22 mmol) is added slowly during 10 minutes, and the reaction mixture is stirred at RT for 1 hour to form a yellowish suspension. After filtration and drying, the title compound is obtained in pure form. 1H NMR (DMSO, 400 MHz) δ 2.53 (s, 3H), 4.06 (s, 3H), 6.71 (s, 1H), 7.57 (d, J=9.0 Hz, 1H), 8.30 (d, J=9.0 Hz, 1H); ES-MS: 268 [M+H]+.

Provenance & Evidence