Triethylamine → (7-Bromo-1,1-dioxo-1,4-dihydro-1lambda6-pyrido[2,3-e][1,2,4]thiadiazin-3-yl)-acetic acid ethyl ester

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Reaction Conditions

Reaction Steps

In a sealed tube, N-(5-Bromo-3-sulfamoyl-pyridin-2-yl)-malonamic acid ethyl ester (2.2 g, 6.0 mmol) was suspended in toluene (44 mL) and triethylamine (11 mL, 78.9 mmol) was added. The mixture was heated at 110° C. while stirring for 30 min. The solid was completely dissolved, yet an immiscible, oily residue was observed along the bottom of the flask. Upon cooling to 25° C., ethyl acetate (˜50 mL) was added. Everything became miscible. The solution was concentrated in vacuo to afford a golden oil. The oil was dissolved in methanol (˜50 mL) and concentrated in vacuo to afford the crude product, (7-bromo-1,1-dioxo-1,4-dihydro-1λ6-pyrido[2,3-e][1,2,4]thiadiazin-3-yl)-acetic acid ethyl ester (2.18 g, >6.0 mmol, 100%, still contained some solvent), as a golden oil. LC-MS (ESI) calcd for C10H10BrN3O4S 346.96, found 348.1 (100%), 349.2 (10%), 350.2 (99%) [M+H+].

Provenance & Evidence