反应详情

温度

0 °C

Into a 5 liter, 3-neck flask equipped with mechanical stirring, reflux condenser and gas evolution bubbler is placed 335 g (1.33M) of 5-chloro-2-carboxyphenylglycine sodium salt, 2.3 liters acetic anhydride and 421 g of anhydrous sodium acetate. The mixture is brought to reflux and maintained for 3 hours until the evolution of carbon dioxide is nearly complete. The mixture is placed in a beaker while hot and chilled to 0° C. overnight. The next day the product is recovered by filtration and mixed with 2 liters water and stirred for 1 hour to hydrolyze any residual acetic anhydride. This crude material, when dry, is dissolved in the minimum of hot ethyl acetate and allowed to crystallize overnight at 0° C. After filtering and washing with a little cold hexane, and drying in vacuo, the product weighed about 150 g and has a melting point of about 112°-113° C.

1. customInto a 5 liter, 3-neck flask equipped with mechanical stirring
2. temperaturereflux condenser
3. temperatureto reflux
4. filtrationThe next day the product is recovered by filtration
5. additionmixed with 2 liters water
6. dry with materialThis crude material, when dry
7. dissolutionis dissolved in the minimum of hot ethyl acetate
8. customto crystallize overnight at 0° C
9. filtrationAfter filtering
10. washwashing with a little cold hexane
11. customdrying in vacuo