tert-Butyl 4-(2-bromoethyl)piperazine-1-carboxylate → tert-butyl 4-(2-(3-((3-ethyl-4-(imidazo[1,2-a]pyridine-3-carboxamido)-1H-indazol-1-yl)methyl)-1H-pyrazol-1-yl)ethyl)piperazine-1-carboxylate

Participants

Reaction Steps

To a solution of N-(1-((1H-pyrazol-3-yl)methyl)-3-ethyl-1H-indazol-4-yl)imidazo[1,2-a]pyridine-3-carboxamide (40.0 mg; 0.104 mmol) in dry DMF (0.5 mL) was added tert-butyl 4-(2-bromoethyl)piperazine-1-carboxylate (30.4 mg; 0.104 mmol) and cesium hydroxide hydrate (17.4 mg; 0.104 mmol). The mixture was stirred under a nitrogen atmosphere for 30 minutes. The mixture was filtered, washing with methanol and ethyl acetate, and the solvent was removed under reduced pressure. The residue (a mixture of two regioisomers) was purified by preparative thin layer chromatography on silica, eluting with 10% methanol in dichloromethane. The desired isomer tert-butyl 4-(2-(3-((3-ethyl-4-(imidazo[1,2-a]pyridine-3-carboxamido)-1H-indazol-1-yl)methyl)-1H-pyrazol-1-yl)ethyl)piperazine-1-carboxylate was isolated (21.5 mg) along with some of the alternate isomer.

Provenance & Evidence