Triethylamine → 7-Bromo-6-fluoro-1,2-dihydroisoquinolin-1-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 4.0 g (16.3 mmol) of 3-(4-bromo-3-fluoro-phenyl)-acrylic acid in 60 mL acetone were subsequently added at 0-5° C. 2.0 g (19.6 mmol) triethylamine in 10 mL of acetone followed by 2.3 g (21.2 mmol) of ethyl chloroformate in 10 mL of acetone. After stirring for 1 h at 0-5° C. a solution of 1.6 g (24.5 mmol) of sodium azide in 9 mL of water was added. After stirring for 1 additional h the reaction mixture was poured onto 200 mL ice water and extraced with chloroform twice. The organic phase was dried over magnesium sulfate, 24 mL of diphenylether were added and the chloroform was cautiously removed in vacuo. The residue was then added dropwise into 60 mL of diphenylether, which had been preheated to 250° C. After complete addition the reaction mixture was stirred for additional 30 minutes at 230-250° C. After cooling down to 100° C. the reaction mixture was poured into 100 mL of heptane and after further cooling in an ice bath the precipitated product was filtered by suction and 2.4 g of crude 7-bromo-6-fluoro-2H-isoquinolin-1-one were obtained.

Provenance & Evidence