反应详情

A sample of 1.51 g of sodium hydride (60% in oil) is washed with hexane under argon to remove the oil. To the washed sodium hydride is added 5 ml of N,N-dimethylformamide. To this mixture is added dropwise a solution of 8.69 g of ethyl 4-[(2-methylbenzoyl)amino]benzoate in 20 ml of N,N-dimethylformamide. The mixture is stirred at room temperature for 0.5 hour and then 5.23 g of methyl iodide is added. The mixture is stirred at room temperature for 16 hours. The mixture is diluted with water and extracted with dichloromethane. The extract is dried (Na2SO4), concentrated to reduce the volume and the solution filtered through a thin pad of hydrous magnesium silicate. The filtrate is concentrated in vacuo to give 11 g of an oil (1:1 mixture of product and N,N-dimethylformamide). The preceding product, ethyl 4-[N-methyl-N-(2-methylbenzoyl)amino]benzoate, (11 g) is dissolved in 30 ml of methanol and 25 ml of 2N NaOH added. The mixture is refluxed for 2 hours and the solvent removed. The residue is extracted with ether (discard) and the remaining residue dissolved in 50 ml of water. The basic solution is acidified with 2N citric acid and the solid filtered off and washed with water. The product is air dried to give 6.72 g of crystals, m.p. 187°-190° C.

1. temperatureThe mixture is refluxed for 2 hours
2. customthe solvent removed
3. extractionThe residue is extracted with ether (discard)
4. dissolutionthe remaining residue dissolved in 50 ml of water
5. filtrationthe solid filtered off
6. washwashed with water
7. customdried