반응 #8666

반응 방정식

2-fluorobenzyl-hydrazine

trifluoroacetic acid

sodium

ethyl cyanopyruvate

→

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

용매

dioxane

반응 조건

후처리

1. 1
   workup.DISSOLUTIONdissolves
2. 2
   workup.WAITthe mixture is boiled overnight
3. 3
   온도After cooling
4. 4
   기타the sodium trifluoroacetate crystals which have separated out
5. 5
   여과are filtered off with suction
6. 6
   세척washed with dioxane
7. 7
   기타the remaining crude solution is reacted further

실험 절차

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.

출처