Cesium carbonate → 4-((S)-4-tert-Butoxycarbonyl-2-{[5-(1-ethoxycarbonyl-cyclobutoxy)-1-(3-methoxy-phenyl)-1H-pyrazole-3-carbonyl]-amino}-butyryl)-piperazine-1-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 100 mg of 4-((S)-4-tert-Butoxycarbonyl-2-{[5-hydroxy-1-(3-methoxy-phenyl)-1H-pyrazole-3-carbonyl]-amino}-butyryl)-piperazine-1-carboxylic acid ethyl ester in 4 ml of DMF, 116 mg of cesium carbonate and 74 mg of 1-Bromo-cyclobutanecarboxylic acid ethyl ester was added and heated to 100° C. for 3 h. Then, the reaction mixture was diluted with water and filtered through a Chem Elut® cartridge by eluting with ethyl acetate. The solvents were removed under reduced pressure. The crude product was used in the subsequent reaction. Yield: 90 mg.

Provenance & Evidence