Triethylamine → 4-(5-Bromo-isoquinolin-6-yloxy)-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

3.75 mL (4.15 g, 23.8 mmol) of diethyl azo dicarboxylate were added to 12.7 g (19.9 mmol) of polymer-bound triphenylphosphine (PS—PPh3, approx. 1.6 mmol/g, Argonaut) in 250 mL of dichloromethane at 0° C. and stirred for 15 min. 4.45 g (19.9 mmol) 5-bromo isoquinoline-6-ol (9), 4.0 g (19.9 mmol) Boc-(4-hydroxy)piperidine and 4.1 mL (3.0 g, 29.8 mmol) triethyl amine were added. The mixture was shaken for 16 h. The polymer was removed by filtration through Celite and the solvents were distilled off. 20 mL dichloromethane were added and the precipitate was isolated by filtration. The crude product (8 g) was purified by flash chromatography using ethyl acetate/n-heptane as eluent to give 4.78 g (60%) of compound 11.

Provenance & Evidence