Water → 7-Chloro-2-[(N-methoxy-N-methylamino)carbonyl]-3-nitroindole

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Reaction Steps

A solution of 7-chloro-3-nitroindole-2-carboxylic acid (step 1, 400 mg, 1.7 mmol) in thionyl chloride (2 ml) was heated at 70° C. for 3 h, the mixture cooled and concentrated. The residue was dissolved in dichloromethane (20 ml). To the solution was added N,O-dimethylhydroxylamine hydrochloride (326 mg, 3.4 mmol) and pyridine (0.27 ml, 3.4 mmol). After stirring for 16 h, the mixture was poured into water (100 ml) and extracted with ethyl acetate (200 ml). The organic layer was washed with 2N aqueous HCl (100 ml), water (100 ml), saturated aqueous sodium bicabonate (100 ml), brine (100 ml), and dried (MgSO4). After removal of solvent, the residue was purified by flash column chromatography eluting with ethyl acetate/hexane (1:10˜1:1) to give 420 mg (87%) of the title compound. tlc: Rf=0.55 (25% ethyl acetate in hexanes)

Provenance & Evidence