Urea → methyl 6-(4-morpholinyl)-2-oxo-2,3-dihydro-1H-benzimidazole-4-carboxylate

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Reaction Conditions

Reaction Steps

To a solution of methyl 2,3-diamino-5-(4-morpholinyl)benzoate, prepared as described in Example 45, step a (11.0 g, 4.0 mmol) in DMF (50 mL) was added urea (720 mg, 12 mmol) and the mixture was heated to 170° C. for 4 h. When analysis by TLC showed no starting material remaining, the mixture was cooled to room temperature then diluted with DCM (200 mL), washed with water (50 mL×2) and dried over anhydrous Na2SO4, filtered and concentrated in-vacuo. The residue was then purified by chromatography on silica (eluted with EtOAc) to afford the desired product as a dark-yellow solid (690 mg, 62%). 1H NMR (300 MHz, DMSO-d6): δ ppm 3.02 (t, 4H, J=4.8 Hz), 3.74 (t, 4H, J=4.8 Hz), 3.86 (s, 3H), 6.82 (d, 1H, J=2.1 Hz), 6.99 (d, 1H, J=2.1 Hz), 10.48 (s, 1H), 10.82 (s, 1H). LC-MS: m/e=278 [M+1]+.

Provenance & Evidence