Cesium carbonate → tert-butyl 2-(1-isopropyl-1H-1,2,4-triazol-5-yl)-5,6-dihydrobenzo[f]imidazo[1,2-d][1,4]oxazepin-9-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

A mixture of 9-bromo-2-(1-isopropyl-1H-1,2,4-triazol-5-yl)-5,6-dihydrobenzo[f]imidazo[1,2-d][1,4]oxazepine 194 (250 mg, 0.67 mmol), t-butyl carbamate (390 mg, 3.3 mmol), cesium carbonate (440 mg, 1.3 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (58 mg, 0.10 mmol), and tris(dibenzylideneacetone)dipalladium(0) (46 mg, 0.05 mmol) was suspended in 1,4-dioxane (5.2 mL) and heated at 110° C. for 24 hr. The reaction mixture was cooled to ambient temperature, diluted with DCM, and filtered to remove solids. The crude mixture was absorbed onto celite for purification by flash chromatography to afford tert-butyl 2-(1-isopropyl-1H-1,2,4-triazol-5-yl)-5,6-dihydrobenzo[f]imidazo[1,2-d][1,4]oxazepin-9-ylcarbamate as a yellow crystalline solid (170 mg, 61%). 1H NMR (400 MHz, DMSO) δ 9.56 (d, J=12.5 Hz, 1H), 8.27 (d, J=8.8 Hz, 1H), 7.89 (s, 1H), 7.85 (s, 1H), 7.26 (t, J=5.8 Hz, 1H), 7.23-7.14 (m, 1H), 5.89 (hept, J=6.6 Hz, 1H), 4.52-4.42 (m, 4H), 1.47 (d, J=6.6 Hz, 6H)

Provenance & Evidence