Acetic Anhydride → 2-methyl-5-nitro-1H-indole-3-carbonitrile

関与物質

反応手順

2-methyl-5-nitro-1H-indole-3-carbaldehyde (375 mg, 1.84 mmol) and hydroxylamine hydrochloride (380 mg, 5.52 mmol) were suspended in formic acid (10 mL) and DMF (3 mL), and heated at 80° C. until the solution had turned dark orange (30 min). Quantitative conversion to the aldoxime intermediate was confirmed by LC/MS. 4 mL of acetic anhydride were added and heating was continued for 1 h. The reaction solution was diluted with cold water (20 mL), and the product extracted into EtOAc. The organic layer was washed with water (2×50 mL), brine (2×50 mL), dried over MgSO4, and filtered. The solvent was removed in vacuo to yield 2-methyl-5-nitro-1H-indole-3-carbonitrile as an ochre-colored solid (330 mg, 89% yield). Mass and purity were confirmed by LC/MS using an acetonitrile gradient with 0.035% TFA/water. Theoretical (M+H)+ m/z for C10H7N3O2=202.05; Found 202.2.

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