Ethanol → Ethyl (7-hydroxy-1,1-dioxido-4H-1,2,4-benzothiadiazin-3-yl)acetate

Participants

Reaction Conditions

Reaction Steps

EtOH (15 mL) and 150 μL of H2SO4 (conc.) were added into the compound 10c (5.03 mmol) and the mixture was heated to 80° C. for 45 minutes with stirring. The solvent was partially evaporated to half of the original volume under reduced pressure. EtOAc (30 mL) was added and the resulted mixture was washed with H2O (15 mL×3) via extraction. The aqueous layer was back extracted with EtOAc once (60 mL) and the combined organic layer was dried over anhydrous MgSO4, filtered, concentrated to give the desired product (4b) (1.11 g) as a gray solid. This crude material was directly used in next step without further purification. LC-MS: (ESI+) m/e=285.10 [M+1]+ (exact ms: 284.05).

Provenance & Evidence