Trimethylpyruvic acid → 1-(4-(2-Fluoro-5-((4-oxo-3,4-dihydrophthalazin-1-yl)methyl)benzoyl)piperazin-1-yl)-3,3-dimethylbutane-1,2-dione

Participants

Reaction Steps

4-(4-fluoro-3-(piperazine-1-carbonyl)benzyl)phthalazin-1(2H)-one TFA salt (310 mg, 0.65 mmol), 3,3-dimethyl-2-oxobutanoic acid [1.37 g (60%), 6.3 mmol], DIPEA (2 ml, 11.6 mmol), and HATU (1030 mg, 2.72 mmol) were mixed in DMF (50 ml), the resulting reaction mixture was stirred at room temperature for 44 h until the reaction finished (monitored by TLC). The reaction mixture was then partitioned between DCM and water (100 ml each, the water phase was extracted with DCM (100 ml). The combined organic phase was washed with water, sat. aqueous sodium bicarbonate, and brine, dried over sodium sulphate, filtered, and concentrated to yield the crude product. Then the crude product was firstly purified by column chromatography on silica gel (DCM:MeOH=100:1) and re-purified by preparative TLC (DCM:MeOH=40:1) to afford the desired product (150 mg, 46.9%) as a off white solid.

Provenance & Evidence