Diisopropylethylamine → (R)-3-tert-Butoxy-2-[(1-chloro-4-hydroxy-isoquinoline-3-carbonyl)-amino]-propionic acid tert-butyl ester

Participants

Reaction Steps

To a mixture of 45 mg (0.2 mmol) of 1-chloro-4-hydroxy-isoquinoline-3-carboxylic acid, 76 mg (0.2 mmol) of benzotriazol-1-yl-(bis-dimethylamino-methylene)-oxonium hexafluoro phosphate (HBTU), 50.8 mg (R)-2-amino-3-tert-butoxy-propionic acid tert-butyl ester hydrochloride (0.2 mmol), and 1 ml of dichloromethane was added 122.5 μl (0.7 mmol) of ethyl-diisopropyl-amine with stirring. Stirring was continued at ambient temperature for 40 h. The product was isolated from the reaction mixture by flash column chromatography on silica gel using hexanes:ethyl acetate (9:1) as the eluent to give a colorless oil. 27 mg of the title compound was obtained; MS-(+)-ion: M+1=422.8 amu.

Provenance & Evidence