Diisopropylethylamine → HCID 118080494, compound

Temperature

50 °C

A 250-mL round-bottom flask was charged with 3,3-difluorocyclobutan-1-ol (2.41 g, 22.3 mmol), 1,2-dichloroethane (50 mL), N,N-diisopropylethyl amine (3.5 mL, 20 mmol) and triphosgene (1.33 g, 4.48 mmol). The resulting solution stirred 30 minutes at 50° C., and then a solution of (S)-1-(6-bromo-2-methyl-3,4-dihydroquinoxaline-1(2H)-yl)ethan-1-one (600 mg, 2.23 mmol) and N,N-diisopropylethyl amine (3.5 mL, 20 mmol) in 1,2-dichloroethane (30 mL) was added. The resulting solution stirred overnight at 50° C. After cooling to room temperature, the reaction mixture was concentrated under vacuum. The residue was dissolved in ethyl acetate (50 mL), washed with saturated sodium carbonate solution (2×50 mL), dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified via column chromatography on silica gel (eluting with 2:3, ethyl acetate/petroleum ether) to afford 3,3-difluorocyclobutyl (S)-4-acetyl-7-bromo-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylate (800 mg, 89%) as a brown solid. MS (ESI, pos. ion) m/z 404, 405 [M+1]+.

1. stirringThe resulting solution stirred overnight at 50° C
2. temperatureAfter cooling to room temperature
3. concentrationthe reaction mixture was concentrated under vacuum
4. dissolutionThe residue was dissolved in ethyl acetate (50 mL)
5. washwashed with saturated sodium carbonate solution (2×50 mL)
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated under vacuum
8. customThe residue was purified via column chromatography on silica gel (eluting with 2:3, ethyl acetate/petroleum ether)

ORD record

ord-80eaccdf84404e0db956151d261dd894

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09422281B2