Chloroacetyl chloride → 2H-1,4-Benzoxazine-8-carboxylic acid, 3,4-dihydro-3-oxo-, ethyl ester

Temperatur

60 °C

To a solution of ethyl 3-amino-2-hydroxybenzoate (500 mg), sodium hydrogen carbonate (927 mg) and benzyltributylammonium bromide (983 mg) in chloroform (10 ml) was added dropwise chloroacetyl chloride (374 mg) in chloroform (3 ml) under ice bath cooling. The reaction mixture was stirred at ambient temperature for 1 hour and at 60° C. for 2 hours. To the reaction mixture was added dropwise chloroacetyl chloride (312 mg) in chloroform (3 ml) under ice bath cooling and stirred at 60° C. for 2 hours. After the reaction mixture was concentrated in vacuo, the residue was diluted with chloroform and saturated sodium hydrogen carbonate aqueous solution. The organic layer was separated and washed with brine. The solution was dried over magnesium sulfate and concentrated in vacuo to give ethyl 2H-1,4-benzoxazin-3-one-8-carboxylate (460 mg).

1. temperaturecooling
2. temperaturecooling
3. stirringstirred at 60° C. for 2 hours
4. concentrationAfter the reaction mixture was concentrated in vacuo
5. additionthe residue was diluted with chloroform and saturated sodium hydrogen carbonate aqueous solution
6. customThe organic layer was separated
7. washwashed with brine
8. dry with materialThe solution was dried over magnesium sulfate
9. concentrationconcentrated in vacuo

ORD-Eintrag

ord-58738d5577134f4a8bc37bfc5fc7d86a

Quelldatensatz

uspto-grants-2001_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06207693B1