反应详情

温度

0 °C

Sodium nitrite (27 g in water) is added at 0° C. to a solution of D-phenylalanine (40 g) in a mixture of 48% hydrobromic acid/water (1:1 by volume). The mixture is stirred for 30 minutes at 0° C. and then for 2 hours 30 minutes at a temperature close to 0° C. The reaction mixture is extracted with ether. The organic extracts are washed with water and a saturated sodium chloride solution and then dried over sodium sulphate. After filtration and concentration to dryness, the obtained residue is purified by distillation. (R)-2-Bromo-3-phenylpropanoic acid (33 g) is obtained which has the following characteristics: B.p.1kPa =154° C.; Rf =0.47 (methylene chloride/methanol). The yield is 60%.

1. customfor 2 hours 30 minutes at a temperature close to 0° C
2. extractionThe reaction mixture is extracted with ether
3. washThe organic extracts are washed with water
4. dry with materiala saturated sodium chloride solution and then dried over sodium sulphate
5. filtrationAfter filtration and concentration to dryness
6. distillationthe obtained residue is purified by distillation