Reaktion #2303472

Reaktionsgleichung

6-amino-4-ethyl-2,3-benzoxazin-1-one

water

4-(benzo[1,3]dioxol-4-yl)-4-methyl-2-oxo-pentanoic acid

thionyl chloride

→

6-[4-(benzo[1,3]dioxol-4-yl)-4-methyl-2-oxo-valeroyl-amino]-4-methyl-2,3-benzoxazin-1-one

Ausbeute 40.2%

Lösungsmittel

dimethylacetamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGIt is stirred for 96 hours at room temperature
2. 2
   Extraktionextracted with ethyl acetate
3. 3
   Waschenthe organic phase is washed with water
4. 4
   Trocknendried (Na2SO4)
5. 5
   Einengenafter the solvent is concentrated by evaporation

Vorschrift

10 g of 4-(benzo[1,3]dioxol-4-yl)-4-methyl-2-oxo-pentanoic acid is dissolved in 125 ml of dimethylacetamide and mixed with 3.5 ml of thionyl chloride under argon at −0° C. After 20 minutes of stirring at −3 to +3° C., 7.6 g of 6-amino-4-ethyl-2,3-benzoxazin-1-one (WO00/32584) is added. It is stirred for 96 hours at room temperature, then mixed with water, extracted with ethyl acetate, the organic phase is washed with water, dried (Na2SO4), and after the solvent is concentrated by evaporation and after chromatography of the crude product on silica gel with hexane/ethyl acetate (100:0→60:40), 6.56 g of 6-[4-(benzo[1,3]dioxol-4-yl)-4-methyl-2-oxo-valeroyl-amino]-4-methyl-2,3-benzoxazin-1-one is obtained as a beige solid.

Quelle