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

Participants

Reaction Conditions

Reaction Steps

A 250-mL flask equipped with a thermometer and nitrogen bubbler was charged with 6-chloro-8-methyl-2H-3,1-benzoxazine-2,4(1H)-dione (9.0 g, 43 mmol) (i.e. the product of Example 1), ethyl acetate (50 mL), and acetic acid (3.8 g, 63 mmol). The mixture was heated to 50° C., and anhydrous methylamine (1.6 g, 50 mmol) was added below the surface of the mixture while maintaining the temperature at 48-52° C. The mixture was held for 1 h at 50° C., then water (65 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 3 h to 10° C. The solid was collected by filtration and dried to afford the title compound as a white crystalline solid (7.94 g, >98.5 wt. % purity by HPLC assay, 93% yield) melting at 143-145° C.

Provenance & Evidence