Metronidazole → Metronidazole Carbonate

mPEG1kDaOH (1.0 mmol, 1.0 g) and DMAP (2.4 mmol) were dissolved in anhydrous DCM (20 ml). Triphosgene (0.33 mmol, 99 mg) was added at room temperature. The solution was stirred at room temperature for 15 minutes. Metronidazole (1.1 mmol, 188 mg) was added and the reaction solution was stirred at room temperature for four hours. The solvent was evaporated at reduced pressure. The residue was extracted with DCM and 1N HCl solution (20 ml/20 ml) twice. The organic phases were combined and dried with anhydrous Na2SO4. The solid was filtered off and the solvent was evaporated. The residue was precipitated in ethyl ether/IPA (20 ml/10 ml). The compound 2e (590 mg, yield 50%) as solid was obtained by filtration. 1H NMR (CDCl3) δ 7.98 (s, 1H), 4.60 (t, 2H), 4.50 (t, 2H), 4.27 (t, 2H), 3.74-3.54 (m, 96H), 3.39 (s, 3H), 2.52 (s, 3H). MW 1308 [M+H]+.

1. stirringthe reaction solution was stirred at room temperature for four hours
2. customThe solvent was evaporated at reduced pressure
3. extractionThe residue was extracted with DCM and 1N HCl solution (20 ml/20 ml) twice
4. dry with materialdried with anhydrous Na2SO4
5. filtrationThe solid was filtered off
6. customthe solvent was evaporated
7. customThe residue was precipitated in ethyl ether/IPA (20 ml/10 ml)

ORD record

ord-5f13cc67dcea44d8bf6f29d348471ffe

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09233932B2