Water → 4-(4-{6-[3-(4-tert-Butyl-benzoylamino)-phenyl]-imidazo[1,2-a]pyrazin-8-ylamino}-phenyl)-piperazine-1-carboxylic Acid Tert-Butyl Ester

Participants

Reaction Steps

An ice-cold solution of 4-{4-[6-(3-Amino-phenyl)-imidazo[1,2-a]pyrazin-8-ylamino]-phenyl}-piperazine-1-carboxylic acid tert-butyl ester (14) (2.35 mmol), triethylamine (3.53 mmol), and tetrahydrofuran (20 mL) is treated dropwise with a solution of 4-t-butylbenzoyl chloride (2.35 mmol) in tetrahydrofuran (10 mL). The mixture is stirred at room temperature for 1 hr. Water (50 mL) is added and the mixture extracted with ethyl acetate (3×70 mL). The extracts are washed with water (2×50 mL) and brine (1×50 mL), dried over magnesium sulfate, and evaporated in vacuo. The residue is triturated with diethyl ether to give 4-(4-{6-[3-(4-tert-butyl-benzoylamino)-phenyl]-imidazo[1,2-a]pyrazin-8-ylamino}-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (15) as a cream solid.

Provenance & Evidence