Cesium carbonate → HCID 86728125, compound

Participants

Reaction Steps

To a solution of crude tert-butyl N-tert-butoxycarbonyl-N-[(5R)-5-(2-fluoro-5-nitro-phenyl)-6-(2-hydroxyethyl)-2,2,5,6-tetramethyl-1,1-dioxo-1,4-thiazin-3-yl]carbamate (0.18 g, 0.31 mmol) in DMF (1.8 ml) was added cesium carbonate (0.25 g, 0.77 mmol). The resulting mixture was stirred at ambient temperature for 7 h. Extra cesium carbonate (0.36 g) was added and the mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with 30 ml of saturated NH4Cl and extracted with EtOAc. The organic extract was washed with brine and dried over MgSO4. The solution was filtered and concentrated in vacuo to give the crude material as an orange oil. The crude material was absorbed onto a plug of silica gel and purified by chromatography through a Biotage column (25 g), eluting with a gradient of 5% to 40% EtOAc in hexane, to provide tert-butyl N-[(11bR)-3,3,4a,11b-tetramethyl-10-nitro-4,4-dioxo-5,6-dihydro-[1]benzoxepino[4,5-b][1,4]thiazin-2-yl]-N-tert-butoxycarbonyl-carbamate (0.076 g, 43% yield) as a light-yellow solid. m/z (ESI) 591.1 (M+Na)+.

Provenance & Evidence