反应详情

##STR11## To an ice cold solution of piperazine-2,3-dicarboxylic acid (1.74 g/0.01 mole) in aqueous sodium hydroxide (1.2 g/20 ml) was added 4-bromobenzoyl chloride (2.2 g/0.01 mole) over 30 min. The resulting solution was stirred at 0° for 2 h, then allowed to warm to room temperature overnight. The solution was applied to a column of Dowex AG-1-acetate resin and the ninhydrin positive fractions of the 3M acetic acid eluate were combined and evaporated to dryness. Recrystallization of the residue from a 50% aqueous ethanol solution yielded 4-(4-bromobenzoyl)-piperazine-2,3-dicarboxylic acid (800 mg) as a white solid m.p., 218°-20°.

1. customevaporated to dryness
2. customRecrystallization of the residue from a 50% aqueous ethanol solution