Triethylamine → Apixaban

Participants

Reaction Steps

Method A. A suspension of 1-(4-methoxy-phenyl)-7-oxo-6-[4-(2-oxo-piperidin-1-yl)-phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine-3-carboxylic acid (61, 1.5 g, 3.3 mmol) in EtOAc (20 mL) was treated with triethylamine (TEA, 433 mg, 0.60 mL, 4.3 mmol, 1.3 equiv) at room temperature, and the resulting reaction mixture was treated dropwise with iso-butyl chloroformate (587 mg, 0.55 mL, 4.3 mmol, 1.3 equiv) at room temperature. The resulting reaction mixture was subsequently stirred at room temperature for an additional 30 min. When TLC and HPLC showed the mixed anhydride formation reaction was complete, the reaction mixture was poured into a cold (0–5° C.) ammonium hydroxide solution (NH4OH, 28% aqueous solution, 25 mL) with good stirring. The resulting mixture was stirred at room temperature for an additional 4 h. The solids were collected by filtration, washed with a mixture of methanol and water (1:1 v/v, 2×20 mL), and dried in vacuo at 40–45° C. for 12 h to afford the crude desired 1-(4-methoxy-phenyl)-7-oxo-6-[4-(2-oxo-piperidin-1-yl)-phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine-3-carboxylic acid amide (62, 1.06 g, 1.52 g theoretical, 70%) as off-white crystals. For 62, CIMS m/z 460 (M++H, C25H25N5O4).

Provenance & Evidence