Acetic Acid → 2-Amino-5-Chloro-N,3-Dimethylbenzamide

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence