Hydrochloric Acid → 6-chloro-4-methyl-3,4-dihydro-2H-1,4-benzoxazine-8-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

7.1 Grams of methyl 6-chloro-4-methyl-3,4-dihydro-2H-1,4-benzoxazine-8-carboxylate and 3.8 g of sodium hydroxide were dissolved in a mixed solvent obtained by mixing 50 ml of methanol and 100 ml of water, and the resulting solution was heated at 70° C. for 2 hours with stirring. The liquid reaction mixture was added to 300 ml of water, and 6 ml of concentrated hydrochloric acid was added thereto. The resulting insoluble substance was filtered off, washed with water, and dried, thereby obtaining 5.8 g of 6-chloro-4-methyl- 3,4-dihydro-2H-1,4-benzoxazine-8-carboxylic acid. Melting point: 202°-204° C.

Provenance & Evidence