反应详情

1.5 g of diethyl 2-(tert-butoxyformamido)-2-[(5-oxazolyl)methyl]malonate were dissolved in 1.5 ml of water and 1.5 ml of ethanol. 337 mg of sodium hydroxide were added and the mixture was stirred overnight at room temperature. The mixture was then acidified to pH 5 with acetic acid and the solvent was removed by evaporation. The residue was dissolved in 5 ml of toluene and 0.64 ml of triethylamine was added. The mixture was heated at reflux for 2 hours and then the solvents were evaporated. Ethyl acetate was added and the solution was washed with saturated aqueous citric acid solution. The organic layer was dried over magnesium sulphate to give 1.224 g of crude N-(tert-butoxycarbonyl)-3(5-oxazolyl)-DL-alanine, 1H NMR (250 MHZ, d6-DMSO) δ: 1.4 (s,9H), 3.0-3.3 (m,2H), 6.95 (s,1H), 7.25 (m, 1H), 8.3 (s,1H).

1. customthe solvent was removed by evaporation
2. dissolutionThe residue was dissolved in 5 ml of toluene
3. addition0.64 ml of triethylamine was added
4. temperatureThe mixture was heated
5. temperatureat reflux for 2 hours
6. customthe solvents were evaporated
7. additionEthyl acetate was added
8. washthe solution was washed with saturated aqueous citric acid solution
9. dry with materialThe organic layer was dried over magnesium sulphate