Hydrochloric Acid → 2-(8-(benzo[d]thiazol-2-ylcarbamoyl)-3,4-dihydroisoquinolin-2(1H)-yl)-5-(3-phenoxypropyl)thiazole-4-carboxylic acid

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Reaction Steps

The title compound 2-(8-(benzo[d]thiazol-2-ylcarbamoyl)-3,4-dihydroisoquinolin-2(1H)-yl)-5-(3-phenoxypropyl)thiazole-4-carboxylic acid (2) was prepared by the following procedure: To phenol (22.6 mg, 0.24 mmol) in DMF (2 mL) was added NaH (60% oil dispersion) (24 mg, 0.6 mmol). After stirring at rt for 5 minutes, ethyl 2-(8-(benzo[d]thiazol-2-ylcarbamoyl)-3,4-dihydroisoquinolin-2(1H)-yl)-5-(3-iodopropyl)thiazole-4-carboxylate (2C) (127 mg, 0.2 mmol) was added and stirring was continued for 1 hour. The reaction mixture was acidified with 1N HCl and the precipitate was filtered and washed with water. The precipitate was slurried in Et2O, filtered and washed with additional Et2O. The resulting solid was purified by column chromatography on silica gel eluting with a gradient of 0 to 2% MeOH in DCM. To the purified material in DMF (1 mL) was added NaOH (4N aq) (0.5 mL, 2 mmol), heated at 50° C. for 5 hours, cooled to rt, and acidified with 1N HCl. The precipitate was filtered, washed with water, slurried in Et2O, filtered, washed with Et2O and dried in a vacuum oven to provide the desired product 2-(8-(benzo[d]thiazol-2-ylcarbamoyl)-3,4-dihydroisoquinolin-2(1H)-yl)-5-(3-phenoxypropyl)thiazole-4-carboxylic acid (2) in 37% yield. 1H NMR (300 MHz, DMSO-d6) δ ppm 12.89 (s, 1H), 12.49 (1H, s), 8.04 (1H, d), 7.79 (1H, d), 7.67 (1H, d), 7.44 (4H, m), 7.25 (2H, m), 6.88 (3H, m), 4.82 (2H, s), 3.96 (2H, t), 3.72 (2H, t), 3.17 (2H, m), 3.03 (2H, t), 2.00 (2H, m). MS (ESI(+)): m/z 571 (M+H).

Provenance & Evidence