Diisopropylamine → 4-[4-(5-Bromo-1-oxo-1,2-dihydro-isoquinolin-3-yl)-benzyl]-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of N,N-diisopropylamine (1.56 mL, 11.10 mmol) in THF (5 mL) under N2 at −78° C. was added n-BuLi (2.5M in hexanes) (4.44 mL, 11.10 mmol) and the reaction stirred at −78° C. for 20 min, after which time a solution of 3-bromo-N,N-diethyl-2-methyl-benzamide (1 g, 3.70 mmol) in THF (5 mL) was added, and the reaction stirred at −78° C. for 30 minutes. A solution of 4-(4-cyano-benzyl)-piperazine-1-carboxylic acid tert-butyl ester (1.15 g, 3.70 mmol) in THF (5 mL) was added and the reaction stirred at −78° C. for 2 h. The reaction was quenched with ice and water, EtOAc added and concentrated in vacuo. The crude material was purified by silica gel column chromatography, eluting with isohexane and increasing the polarity to 100% EtOAc to afford 4-[4-(5-bromo-1-oxo-1,2-dihydro-isoquinolin-3-yl)-benzyl]-piperazine-1-carboxylic acid tert-butyl ester as a cream solid (1.22 g, 66%).

Provenance & Evidence