Ethyl Acetate → (S)-2-ethyl-7-methoxycarbonyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine

関与物質

反応手順

To a solution of 2-amino-5-methoxycarbonylphenol [Tetrahedron, 46(15), 5177-5186 (1990)] (7.50 g) in a mixed solvent of ethyl acetate (60 ml) and water (60 ml) were added sodium hydrogen carbonate (5.20 g) and (R)-2-chlorobutyryl chloride (7.50 g) and the mixture was stirred at room temperature for 10 minutes. The organic layer was separated and the solvent was distilled off under reduced pressure. The resulting residue was dissolved in dimethylformamide (90 ml), to the solution was added potassium carbonate (6.20 g) and the mixture was stirred at room temperature overnight. Water was added to the reaction solution and the resulting crystals were taken by filtration to give (S)-2-ethyl-7-methoxycarbonyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine (9.38 g).

情報源と証拠