Sodium Hydroxide → 3-methyl-2-oxo-2,3-dihydro-1H-1,3-benzodiazole-5-carboxylic acid

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Reaction Conditions

Reaction Steps

Add 1N sodium hydroxide (6.1 mL, 6.1 mmol) to a suspension of methyl 3-methyl-2-oxo-2,3-dihydro-1H-benzo[d]imidazole-5-carboxylate (420 mg, 2.04 mmol) in methanol (10 mL). The suspension turned to a solution upon addition of 1N sodium hydroxide. Stir at 65° C. for 16 hours. Cool to room temperature then concentrate to remove the methanol. Extract the aqueous with ethyl acetate (5 mL). Acidify the aqueous with 2N hydrogen chloride (3 mL) to pH˜2. Concentrate the aqueous layer to a solid. Triturate the solid with water (3 mL). Filter the precipitate and dry under high vacuum to yield the title compound (234 mg, 59%) as a pale brown solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 3.28 (s, 3 H), 7.01 (d, J=8.21 Hz, 1 H), 7.57 (s, 1 H), 7.63 (dd, J=8.11, 1.27 Hz, 1 H), 11.19 (s, 1 H), 12.60 (s, 1 H).

Provenance & Evidence