Lithium Hydroxide → 1-[(2,3-dichlorophenyl)methyl]-6-(4-morpholinyl)-2-(trifluoromethyl)-1H-benzimidazole-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 1-[(2,3-dichlorophenyl)methyl]-6-(4-morpholinyl)-2-(trifluoromethyl)-1H-benzimidazole-4-carboxylate prepared as described in Example 51 (1.95 g, 3.99 mmol) and 2 M lithium hydroxide (0.096 g, 3.99 mmol) in Tetrahydrofuran (THF) was stirred at 50° C. for 3 h. The reaction was cooled to room temperature, the organic solvent was removed under reduced pressure and the aqueous residue was acidified (pH 4) by the addition of 1N HCl. A gummy precipitate formed. After standing at rt overnight, it turned into a solid. The precipitate was collected, washed with water and dried to give crude desired product (1.83 g, 3.86 mmol, 97% yield) as a gray solid. A portion of this material (148 mg) was purified by reverse phase-HPLC (15-95% AcCN in water plus 0.1% TFA). The fractions containing product were combined and the volume was reduced to about ⅓ of the original. The precipitate formed was collected, washed with water and dried in a vacuum oven to give desired product (88.3 mg, 0.182 mmol, 4.57% yield). 1H NMR (400 MHz, DMSO-d6) δ ppm 13.09 (s, 1H), 7.64 (d, J=2.53 Hz, 1H), 7.61 (dd, J=8.08, 1.26 Hz, 1H), 7.44 (d, J=2.27 Hz, 1H), 7.24 (t, J=8.08 Hz, 1H), 6.26 (dd, J=7.83, 1.26 Hz, 1H), 5.77 (s, 2H), 3.66-3.81 (m, 4H), 3.12-3.25 (m, 4H). MS (ES+) m/e 474 [M+H]+.

Provenance & Evidence