Diclofenac → Diclofenac lactam

Participants

Reaction Steps

To a stirred solution of [2-(2,6-Dichloro-phenylamino)-phenyl]-acetic acid] 2 (4.0 g, 0.01 mol, 1 eq) and N—BOC-Ethanolamine (2.39 g, 0.01 mol) in DCM (70 mL) was added DMAP (0.16 g, 0.001 mol) at rt. To this mixture was added DCC (5.5 g, 0.02 mol) in DCM (30 mL) drop-wise at 0-5° C. and resulting mixture was stirred at room temperature for 1 h. Reaction was monitored by TLC. After completion, reaction mixture was filtered and the solvent was removed under reduced pressure. Residue was dissolved in water (100 mL) and extracted with DCM (2×50 mL). Combined organic layer was dried over anhydrous Na2SO4 and evaporated under reduced pressure to obtained crude compound which was washed with hexane (2×20 mL), dried to get 6.0 g crude of Compound 4 and cyclized compound 1 as an off white solid. This mixture was used in the next step without any further purification; Mass: 439.3 (M++H).

Provenance & Evidence