Hydrochloric Acid → HCID 82403920, compound

Temperature

50 °C

A 40 mL reaction vial was charged with (S)-tert-butyl 4-acetyl-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylate (0.35 g, 1.21 mmol) and 1,4-dioxane (6 mL). HCl (4 M solution in 1,4-dioxane, 3.0 mL, 12.1 mmol) was then added, and the reaction mixture was heated to 50° C. for 2 hrs on a heater shaker. The reaction concentrated under reduced pressure and the residue was dissolved in ethyl acetate (20 mL) and washed with saturated aqueous sodium bicarbonate (20 mL). The organic layer was removed and set aside. The aqueous layer was washed with another portion of ethyl acetate (20 mL) and the organic layers were combined and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (gradient elution with 2:1 hexanes-ethyl acetate to 1:1 hexanes-ethyl acetate) to afford ((S)-1-(2-methyl-3,4-dihydroquinoxaline-1(2H)-yl)ethanone (0.2 g, 1.05 mmol, 87% yield) as a colorless oil. MS poor ionization (ESI, -acetate fragment) m/z 149 [M+1]+.

1. customA 40 mL reaction
2. concentrationThe reaction concentrated under reduced pressure
3. dissolutionthe residue was dissolved in ethyl acetate (20 mL)
4. washwashed with saturated aqueous sodium bicarbonate (20 mL)
5. customThe organic layer was removed
6. washThe aqueous layer was washed with another portion of ethyl acetate (20 mL)
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by column chromatography on silica gel (gradient elution with 2:1 hexanes-ethyl acetate to 1:1 hexanes-ethyl acetate)

ORD record

ord-a94675cd4a634f43bddc4af74e952b1a

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09422281B2