Reaktion #1779366

Reaktionsgleichung

6-chloro-8-methyl-2H-3,1-benzoxazine-2,4(1H)-dione

ethyl acetate

acetic acid

methylamine

→

title compound

Ausbeute 94.0%

2-Amino-5-chloro-N,3-dimethylbenzamide

Ausbeute 94.0%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA 250-mL flask equipped with thermometer and nitrogen bubbler
2. 2
   Temperaturwhile maintaining the temperature at 22-41° C
3. 3
   Sonstigethe ethyl acetate was removed by distillation
4. 4
   Sonstigereached 83° C.
5. 5
   Temperaturthe product slurry was cooled over about 2 h to 10° C
6. 6
   FiltrationThe solid was collected by filtration
7. 7
   Waschenwashed with water
8. 8
   Sonstigedried

Vorschrift

A 250-mL flask equipped with thermometer and nitrogen bubbler was charged with 6-chloro-8-methyl-2H-3,1-benzoxazine-2,4(1H)-dione (21.0 g, 0.099 mol) (i.e. the product of Example 1), ethyl acetate (100 mL), and acetic acid (12.6 g, 0.21 mol). The mixture was stirred at 22° C., and anhydrous methylamine (4.3 g, 0.14 mol) was added below the surface of the mixture in portions over 45 minutes while maintaining the temperature at 22-41° C. The mixture was held for 2 h at 40° C., then water (150 mL) was added, and the ethyl acetate was removed by distillation. When the pot temperature reached 83° C., the solution was seeded, and the product slurry was cooled over about 2 h to 10° C. The solid was collected by filtration, washed with water and dried to afford the title compound as a white crystalline solid (18.38 g, >97.4 wt. % purity by HPLC, 94% yield) melting at 143-145° C.

Quelle