Sodium Hydroxide → 3-cyclopentyl-2-(4-cyclopentylmethoxy-6-oxo-6H-pyridazin-1-yl)-propionic acid

Participants

Reaction Conditions

Reaction Steps

A solution of 3-cyclopentyl-2-(4-cyclopentylmethoxy-6-oxo-6H-pyridazin-1-yl)-propionic acid methyl ester (702.6 g, 2.01 mmol) in methanol (1.3 mL, 1.55M) was treated with a 4N aqueous sodium hydroxide solution (0.55 mL, 2.22 mmol) and stirred at 25° C. overnight. After this time, the reaction was concentrated in vacuo. The resulting solids were then taken up in water (30 mL) and a 1N aqueous sodium hydroxide solution (20 mL) and extracted with methylene chloride (1×30 mL). The aqueous layer was then acidified with a 3N aqueous hydrochloric acid solution. The resulting precipitate was collected by filtration and dried in vacuo. The initial organics were treated with a 1N aqueous sodium hydroxide solution (50 mL), concentrated in vacuo, and then acidified with a 3N aqueous hydrochloric acid solution. The resulting precipitate was collected by filtration and dried in vacuo. The combined solids afforded 3-cyclopentyl-2-(4-cyclopentylmethoxy-6-oxo-6H-pyridazin-1-yl)-propionic acid (490.5 mg, 73%) as a white solid; ES+-HRMS m/e calcd for C18H26N2O4 [M+H+] 335.1966, found 335.1964. 1H NMR (400 MHz, DMSO-d6) δ ppm 0.95-1.18 (m, 2H), 1.24-1.82 (m, 15H), 1.94 (ddd, J=13.6, 9.0, 4.0 Hz, 1H), 2.16 (ddd, J=13.8, 11.1, 5.1 Hz, 1H), 2.25-2.36 (m, 1H), 3.90 (d, J=7.0 Hz, 2H), 5.31 (dd, J=11.1, 4.0 Hz, 1H), 6.29 (d, J=2.8 Hz, 1H), 7.81 (d, J=2.8 Hz, 1H), 12.92 (br s, 1H).

Provenance & Evidence