Water → HCID 14771559, compound

Participants

Reaction Steps

To a solution of 4.2 g of methyl 6-chloro-3,4-dihydro-2,2-dimethyl-3-oxo-2H-1,4-benzoxazine-8-carboxylate in 20 ml of dimethylformamide is added 2.27 g of potassium t-butoxide, and the solution stirred at room temperature for 30 minutes. To the resultant solution is added dropwise a solution of 2.95 g of methyl iodide in 5 ml of dimethylformamide, and the solution stirred for 2.5 hours. To the resulting solution are added water and ethyl acetate to separate the organic layer followed by washing with water and drying over magnesium sulfate. After the solvent is distilled off under reduced pressure, to the residue are added 50 ml of ethanol and 50 ml of diluted aqueous sodium hydroxide solution and the system stirred at room temperature for 15 hours. To the resultant solution is added diluted hydrochloric acid and the precipitated crystals are collected by filtration and dried to give 3.9 g of 6-chloro-3,4-dihydro-2,2,4-trimethyl-3-oxo-2H-1,4-benzoxazine-8-carboxylic acid, melting at 235°-236° C.

Provenance & Evidence