Picolinic acid → N,N'-bis(picolinoyl)-4,4'-diaminobenzophenone

Participants

Reaction Steps

To a stirred solution of 4,4′-diaminobenzophenone (637 mg, 3.00 mmol) in DMF (30 mL) was added sequentially IPr2NEt (5.30 mL, 30.4 mmol), HOBt (1.23 g, 9.10 mmol), picolinic acid (1.14 g, 9.00 mmol) and BOP reagent (3.98 g, 9.0 mmol). After 17 h at room temperature, the reaction mixture was concentrated in vacuo to ca. 20 mL and added to a rapidly-stirred mixture of EtOAc (100 mL), H2O (100 mL), and sat'd NaCl (100 mL). After stirring for ca 1 h, the phases were separated and the aqueous layer was extracted with EtOAc (2×100 mL). The combined organic layers were washed with H2O (100 mL), dried over MgSO4, filtered, and concentrated in vacuo to a brown solid. Purification by flash chromatography (silica gel, 1% MeOH/CHCl3) afforded 303 mg (24%) of the desired product as a yellow solid. MS (ES+) m/z [M+H]+.

Provenance & Evidence