Metronidazole → Metronidazole Carbonate

Participants

Reaction Steps

mPEG21OH (0.21 mmol, 200 mg) and DMAP (1.0 mmol) were dissolved in anhydrous DCM (10 ml). Triphosgene (0.13 mmol, 39 mg) was added at room temperature. The solution was stirred at room temperature for 5 minutes. Metronidazole (1.0 mmol, 171 mg) was added and the reaction solution was stirred at room temperature overnight. The solvent was evaporated at reduced pressure. The residue was extracted with EtOAc/H2O (20 ml/20 ml) three times. The aqueous phases were combined and adjusted to PH 4.0 by adding 0.1N HCl solution. The solution was extracted with DCM (3×20 ml). The organic phases were combined and dried with anhydrous Na2SO4. The solid was filtered off and the solvent was evaporated to give compound 2d (220 mg, yield 90%). 1H NMR (CDCl3) δ 7.89 (s, 1H), 4.53 (t, 2H), 4.43 (t, 2H), 4.19 (t, 2H), 3.63-3.46 (m, 80H), 3.31 (s, 3H), 2.45 (s, 3H). LC/MS 1154 [M+H]+.

Provenance & Evidence