Iodoethane → 3-oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carboxylic acid {1-[2-(4-ethoxy-6-methoxy-[1,5]naphthyridin-3-yloxy)-ethyl]-piperidin-4-yl}-amide

Participants

Reaction Steps

Ethyl iodide (13 μL, 0.16 mmol, 1.0 eq) is added at room temperature to a stirred solution of 3-oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carboxylic acid {1-[2-(4-hydroxy-6-methoxy-[1,5]naphthyridin-3-yloxy)-ethyl]-piperidin-4-yl}-amide (90 mg, 0.16 mmol, 1.0 eq) in N,N-dimethylformamide (4 mL), followed by potassium carbonate (22 mg, 0.16 mmol, 1.0 eq). After 3 hours stirring at room temperature, solvent is evaporated and the residue is extracted with dichloromethane (3×10 mL) and water (10 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a residue that is purified by preparative HPLC to afford 3-oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carboxylic acid {1-[2-(4-ethoxy-6-methoxy-[1,5]naphthyridin-3-yloxy)-ethyl]-piperidin-4-yl}-amide as a white lyophilizated powder (29 mg, 32% yield).

Provenance & Evidence