反应 #8666

反应方程式

2-fluorobenzyl-hydrazine

trifluoroacetic acid

sodium

ethyl cyanopyruvate

→

Ethyl 5-amino-1-(2-fluorobenzyl)pyrazole-3-carboxylate

溶剂

dioxane

反应条件

后处理

1. 1
   workup.DISSOLUTIONdissolves
2. 2
   workup.WAITthe mixture is boiled overnight
3. 3
   温度After cooling
4. 4
   其他the sodium trifluoroacetate crystals which have separated out
5. 5
   过滤are filtered off with suction
6. 6
   洗涤washed with dioxane
7. 7
   其他the remaining crude solution is reacted further

实验过程

111.75 g (75 ml, 0.98 mol) of trifluoroacetic acid are added to 100.00 g (0.613 mol) of the sodium salt of ethyl cyanopyruvate (prepared in analogy to Borsche and Manteuffel, Liebigs Ann. 1934, 512, 97) while stirring efficiently in 2.5 l of dioxane at room temperature under argon, and the mixture is stirred for 10 min, during which most of the precursor dissolves. Then 85.93 g (0.613 mol) of 2-fluorobenzyl-hydrazine are added, and the mixture is boiled overnight. After cooling, the sodium trifluoroacetate crystals which have separated out are filtered off with suction and washed with dioxane, and the remaining crude solution is reacted further.

来源