Water → 4-cyclopentyl-7-methoxycarbonyl-2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine

Participants

Reaction Conditions

Reaction Steps

To a solution of 7-methoxycarbonyl-2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine (prepared in Preparation 1) (4.0 g) in dimethylformamide (80 ml) were added 60% sodium hydride (in oil) (0.73 g) and cyclopentyl bromide (2.5 g) and the mixture was stirred at 70° C. for a day. Water was added to the reaction solution and extraction with ethyl acetate was conducted. The solvent was distilled off under reduced pressure and the resulting residue was subjected to purification by column chromatography using chloroform to give 4-cyclopentyl-7-methoxycarbonyl-2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine (2.5 g) as an oil.

Provenance & Evidence