Water → 3-cyclopentyl-2-(1-oxo-1H-phthalazin-2-yl)-propionic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 2H-phthalazin-1-one (1.33 g, 9.1 mmol) in tetrahydrofuran (45.5 mL, 0.2M) cooled to 0° C. was treated with a 60% dispersion of sodium hydride in mineral oil (437 mg, 10.9 mmol). The reaction was stirred at 0° C. for 5 min and then at 25° C. for 30 min. After this time, the reaction was treated with 2-bromo-3-cyclopentyl-propionic acid methyl ester (Intermediate 10, 2.35 g, 10 mmol). The reaction was then warmed to 50° C. where it stirred overnight. At this time, the reaction was cooled to 25° C., poured into water (100 mL), and extracted with methylene chloride (3×100 mL). The organics were dried over sodium sulfate, filtered and concentrated in vacuo. Silica gel column chromatography (ISCO, 80 g, 20-50% ethyl acetate/hexanes) afforded 3-cyclopentyl-2-(1-oxo-1H-phthalazin-2-yl)-propionic acid methyl ester (1.78 g, 61%) as a clear oil; ES+-HRMS m/e calcd for C17H20N2O3 [M+H+] 301.1547 found 301.1546.

Provenance & Evidence