Phthaloyl chloride → Phthalimide

Participants

Reaction Steps

To a solution of MCH17-1 (520 mg), triethyl amine (0.82 mL) and DMAP (24 mg) in 10 mL dichloromethane at 0° C. was added phthaloyl chloride (0.36 mL). The mixture was stirred overnight at rt, diluted with ethyl acetate and washed with 1N HCl, aq. NaHCO3 and brine. It was dried over anhydrous MgSO4, filtered, concentrated and purified by chromatography eluting with 0% to 50% ethyl acetate in hexane to provide 338 mg of phthalimide protected intermediate which was stirred with 5 mL of trifluoroacetic acid at rt for 40 min. The reaction mixture was evaporated to dryness, the residue was suspended in aq. NaHCO3 and extracted 3× with ethyl acetate. The combined organic layer was washed with brine, dried over MgSO4, filtered and evaporated to dryness to obtain 220 mg MCH 17-2.

Provenance & Evidence