Trimethylsilyldiazomethane → methyl 6-fluoro-5-methyl-1H-indole-2-carboxylate

Participants

Reaction Steps

To a cooled solution of 6-Fluoro-5-Methyl-1H-indole-2-carboxylic acid in MeOH/toluene (1C) (200 mL, 1:1) was added TMS-diazomethane (2.0 M solution in diethylether, 1.05 eq.) dropwise and the reaction was allowed to warm up to room temperature over 1 h. The reaction mixture was concentrated and purified using triturating with CH2Cl2 and hexane and collecting the solids by filtration to obtain 6-Fluoro-5-Methyl-1H-indole-2-carboxylic acid methyl ester 1D (3.5 g). The concentrated filtrate was purified using chromatography over SiO2 using 0 to 40% ethyl acetate in hexanes to provide an additional amount of 6-Fluoro-5-Methyl-1H-indole-2-carboxylic acid methyl ester 1D (1.0 g). Overall yield (60%). 1H NMR (400 MHz, d6-DMSO): 2.26 (s, 3H), 3.83 (s, 3H), 7.07 (s, 1H), 7.08 (d, J=10.2 Hz, 1H), 7.49 (d, J=8.1 Hz, 1H), 11.9 (s, 1H).

Provenance & Evidence