Cesium carbonate → [7-Fluoro-2-(4-nitro-phenyl)-1-oxo-1,2-dihydro-isoquinolin-6-yl]-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

In a dry flask was combined trifluoromethanesulfonic acid 7-fluoro-2-(4-nitro-phenyl)-1-oxo-1,2-dihydro-isoquinolin-6-yl ester (0.86 g, 2 mmol), t-butyl carbamate (0.33 g, 2.8 mmol), dry powdered cesium carbonate (1.1 g, 3.4 mmol), 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (Xantphos, 0.14 g, 0.24 mmol), and tris(dibenzylideneacetone)dipalladium(0) (Pd2dba3, 38 mg, 0.08 mmol). Under Ar atmosphere, dry THF (17 mL) was added to the flask, and the mixture was stirred at 75° C. for 25 hr. The reaction was concentrated and purified on silica gel using EtOAc/hexane as eluent to give 0.64 g (80%) of pure [7-Fluoro-2-(4-nitro-phenyl)-1-oxo-1,2-dihydro-isoquinolin-6-yl]-carbamic acid tert-butyl ester as a white solid. RP-HPLC: 5.98 min; ES-MS (M+H)+=400.0; 1H-NMR (DMSO-d6) δ (ppm): 1.47 (s, 9), 6.77 (d, 1), 7.46 (d, 1), 7.78 (d, 2), 7.87 (d, 1), 8.17 (d, 1), 8.33 (d, 2), 9.54 (s, 1).

Provenance & Evidence