反応 #8666

反応方程式

2-fluorobenzyl-hydrazine

trifluoroacetic acid

sodium

ethyl cyanopyruvate

→

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

溶媒

dioxane

反応条件

後処理

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

実験手順

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.

出典