1-Hydroxybenzotriazole → 5-Thiophen-2-yl-isoxazole-3-carboxylic acid {1-[2-(7-methoxy-quinoxalin-2-ylsulfanyl)-ethyl]-piperidin-4-yl}-amide

Participants

Reaction Steps

5-Thiophen-2-yl-isoxazole-3-carboxylic acid (43 mg, 0.22 mmol, 1.0 eq) is added at room temperature to a stirred solution of 1-[2-(7-methoxy-quinoxalin-2-ylsulfanyl)-ethyl]-piperidin-4-ylamine (70 mg, 0.22 mmol, 1.0 eq) in N,N-dimethylformamide (5 mL), followed by 1-hydroxybenzotriazole (32 mg, 0.24 mmol, 1.1 eq), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (47 mg, 0.25 mmol, 1.15 eq) and N,N-diisopropylethylamine (83 μL, 0.48 mmol, 2.25 eq). After 15 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 5-thiophen-2-yl-isoxazole-3-carboxylic acid {1-[2-(7-methoxy-quinoxalin-2-ylsulfanyl)-ethyl]-piperidin-4-yl}-amide as an orange solid (15 mg, 13% yield).

Provenance & Evidence