反应 #56344

反应方程式

sodium chloride

L-thyroxine

trifluoroacetic acid

trifluoroacetic anhydride

→

thyroxine

N-Trifluoroacetylthyroxine

溶剂

H2O

ethyl acetate

反应条件

后处理

1. 1
   其他a suspension formed which
2. 2
   其他The organic phase of the mixture was separated
3. 3
   洗涤washed with saturated aqueous sodium chloride solution
4. 4
   干燥dried over anhydrous magnesium sulfate
5. 5
   过滤filtered
6. 6
   其他evaporated

实验过程

A solution of 20 g [25.6 millimoles (mmol)] of L-thyroxine (Sigma Chemical Co., St. Louis, Missouri USA) in 240 ml of dry ethyl acetate containing 46 ml of trifluoroacetic acid and 7.6 ml of trifluoroacetic anhydride was stirred at 0° C. for one hour. Upon warming to room temperature and adding 200 ml of H2O, a suspension formed which was then saturated with sodium chloride. The organic phase of the mixture was separated, washed with saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, filtered and evaporated to give 21.3 g of the N-protected thyroxine derivative (6). A sample was recrystallized from ether-pentane to give fine crystals, m.p. 233°-235° C. (decomposed).

来源