Sodium Hydroxide → 2-[4-(2-cyano-phenoxy)-6-oxo-6H-pyridazin-1-yl]-3-cyclopentyl-propionic acid

Participants

Reaction Conditions

Reaction Steps

A solution of 2-[4-(2-cyano-phenoxy)-6-oxo-6H-pyridazin-1-yl]-3-cyclopentyl-propionic acid methyl ester (30 g, 82 mmol) in methanol (30 mL) was treated with a 4N aqueous sodium hydroxide solution (26.5 mL, 106 mmol) and stirred at 25° C. for 18 h. At this point, the reaction was concentrated in vacuo and then diluted with water. The translucent aqueous solution was acidified to pH 4-5 with a 1N aqueous hydrochloric acid solution. The resulting precipitate was collected by filtration, rinsed and dried in vacuo to afford 2-[4-(2-cyano-phenoxy)-6-oxo-6H-pyridazin-1-yl]-3-cyclopentyl-propionic acid (12.0 g, 41%) as a white solid; ESI-MS 354 [M+H+]; HPLC: >96% (purity). 1H-NMR (300 MHz, CDCl3) δ 9.65 (s, 1H), 7.93 (s, 1H), 7.68-7.78 (m, 2H), 7.43-7.45 (m, 1H), 7.28-7.31 (m, 1H), 6.07 (s, 1H), 5.51-5.56 (m, 1H), 2.29-2.39 (m, 1H), 2.05-2.15 (m, 1H), 1.44-1.82 (m, 7H), 1.09-1.22 (m, 2H).

Provenance & Evidence