Hydrochloric Acid → 6-(2,6-Dimethoxyphenyl)-1-(4-(trifluoromethoxy)benzyl)piperazine-2,5-dione

A cooled (0° C.) solution of ethyl 2-(2-((tert-butoxycarbonyl)amino)-N-(4-(trifluoromethoxy)-benzyl)acetamido)-2-(2,6-dimethoxyphenyl)acetate (900 mg; 1.57 mmol) in anh. DCM (18 ml) was treated dropwise with 4 M HCl in dioxane (6.00 ml; 24.00 mmol), and the resulting mixture was further stirred at rt, under nitrogen, for 2.5 h. The reaction mixture was concentrated to dryness under reduced pressure, the resulting residue was treated with aq. sat. NaHCO3 (7.5 ml) and AcOEt (7.5 ml), and stirring at rt was then continued for 17 h. The separated aq. layer was extracted with AcOEt (20 ml), and the mixed organic layers were washed with brine, dried over anh. MgSO4, filtered, and concentrated to dryness under reduced pressure affording 6-(2,6-dimethoxyphenyl)-1-(4-(trifluoromethoxy)benzyl)-piperazine-2,5-dione as a slightly orange solid. LC-MS (conditions D): tR=0.94 min.; [M+H]+: 424.88 g/mol.

1. concentrationThe reaction mixture was concentrated to dryness under reduced pressure
2. additionthe resulting residue was treated with aq. sat. NaHCO3 (7.5 ml) and AcOEt (7.5 ml)
3. stirringstirring at rt
4. waitwas then continued for 17 h
5. extractionThe separated aq. layer was extracted with AcOEt (20 ml)
6. washthe mixed organic layers were washed with brine
7. dry with materialdried over anh. MgSO4
8. filtrationfiltered
9. concentrationconcentrated to dryness under reduced pressure

ORD-Eintrag

ord-6ff7e32805c44790bd541ee7908e8be3

Quelldatensatz

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09242970B2