Hydrochloric Acid → 3,3-dimethyl-5-(methyloxy)-6-nitro-2,3-dihydro-1H-indole

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Reaction Conditions

Reaction Steps

A solution of 1-acetyl-3,3-dimethyl-5-(methyloxy)-6-nitro-2,3-dihydro-1H-indole (2.55 g, 9.65 mmol) in methanol (75 mL) was treated with 4.0N HCl in dioxane (19.30 mL, 77 mmol) and maintained at 70° C. for 16 hours. The solution was concentrated under reduced pressure, solids were triturated with diethyl ether and the slurry was filtered to afford 3,3-dimethyl-5-(methyloxy)-6-nitro-2,3-dihydro-1H-indole (2.340 g, 94% yield) as an orange solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.68 (s, 1 H), 7.36 (s, 1 H), 3.89 (s, 3 H), 3.41 (s, 2 H), 1.33 (s, 6 H).

Provenance & Evidence