4-[4-[[4-Amino-5-(3-fluorobenzoyl)-2-thiazolyl]amino]phenyl]-1-piperazinecarboxylic acid, 1,1-dimethylethyl ester → [4-Amino-2-[[4-(1-piperazinyl)phenyl]amino]-5-thiazolyl](3-fluorophenyl)methanone

Participants

Reaction Steps

A mixture of 4-[4-[[4-amino-5-(3-fluorobenzoyl)-2-thiazolyl]amino]phenyl]-1-piperazinecarboxylic acid, 1,1-dimethylethyl ester (75 mg, 0.15 mmol) (from Step A above) and a solution of TFA/CH2Cl2 (1:1; 1.5 mL) was gently shaken for 1.5 h. The solution was evaporated in vacuo. To the residue was added resin-bound N,N-diisopropylethylamine (2.5 g, loading capacity: 3.8 mmol/g from Argonaut, Inc.) and CH2Cl2 (15 mL). After shaking overnight, the mixture was filtered and washed successively with CH3OH and CH2Cl2. The solvent was evaporated in vacuo and the residue was triturated by diethyl ether/hexanes (1/9) to afford [4-amino-2-[[4-(1-piperazinyl)phenyl]amino]-5-thiazolyl](3-fluorophenyl)methanone (60 mg, 100%).

Provenance & Evidence