1,2-Dichloroethane → 2-Ethyl-2H-benzo[b][1,4]oxazin-3(4H)-one

To a solution of 2-bromobutanoic acid (11 mmol, 2145 mg) in DMF (10 ml) was added EDC (12 mmol, 2.3 g) and HOBt (5 mmol, 675 mg) followed by the addition of 2-aminophenol (10 mmol, 1091 mg). The reaction mixture was stirred at room temperature for 2 h, diluted with water and extracted with ethyl acetate. The organic phase was washed with water, brine, dried over Na2SO4 and concentrated under reduced pressure. To the crude product in DMF (5 ml) was added K2CO3 (1.6 g) and the reaction mixture was stirred at room temperature overnight. The reaction mixture was diluted with water and extracted with EtOAc. The organic layer was washed with 1N HCl, Sat. NaHCO3, dried over Na2SO4 and evaporated to dryness. Purification by column chromatography gave the desired product as a white solid. LC/MS (10% to 99%): M/Z (M+H)+ (obs)=178; tR=2.36.

1. extractionextracted with ethyl acetate
2. washThe organic phase was washed with water, brine
3. dry with materialdried over Na2SO4
4. concentrationconcentrated under reduced pressure
5. additionTo the crude product in DMF (5 ml) was added K2CO3 (1.6 g)
6. stirringthe reaction mixture was stirred at room temperature overnight
7. additionThe reaction mixture was diluted with water
8. extractionextracted with EtOAc
9. washThe organic layer was washed with 1N HCl, Sat. NaHCO3
10. dry with materialdried over Na2SO4
11. customevaporated to dryness
12. customPurification by column chromatography

ORD-Eintrag

ord-0294036c999a462f9cb50930541b1754

Quelldatensatz

uspto-grants-2010_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07842686B2