反应 #452450

反应方程式

Hydrazine hydrate

pivaloylacetonitrile

→

3-amino-5-t-butylpyrazole

收率 96.4%

溶剂

Isopropanol

isopropanol

反应条件

后处理

1. 1
   温度heating
2. 2
   温度heating
3. 3
   workup.STIRRINGstirring
4. 4
   workup.DISTILLATIONwas distilled off under reduced pressure
5. 5
   workup.ADDITIONEthyl acetate 2000 ml and a saturated salt aqueous solution were added to a residue
6. 6
   workup.STIRRINGstirring
7. 7
   其他After leaving
8. 8
   其他an aqueous layer was removed
9. 9
   洗涤an ethyl acetate layer was washed twice with the saturated salt aqueous solution
10. 10
    干燥by drying an ethyl acetate solution over magnesium sulfate anhydrous
11. 11
    浓缩This ethyl acetate solution was concentrated under reduced pressure
12. 12
    workup.ADDITIONn-hexane 2000 ml was added to a residue
13. 13
    其他to precipitate crystal
14. 14
    过滤This crystal was filtered off
15. 15
    其他dried

实验过程

Isopropanol 800 ml was added to pivaloylacetonitrile 600 g and heating and stirring were applied. Hydrazine hydrate 288 g was dropped thereto and heating and stirring were applied for 3 hours. After finishing the reaction, isopropanol 400 ml was distilled off under reduced pressure. Ethyl acetate 2000 ml and a saturated salt aqueous solution were added to a residue and stirring was applied. After leaving for standing for a while, an aqueous layer was removed and an ethyl acetate layer was washed twice with the saturated salt aqueous solution, followed by drying an ethyl acetate solution over magnesium sulfate anhydrous. This ethyl acetate solution was concentrated under reduced pressure and then n-hexane 2000 ml was added to a residue to precipitate crystal. This crystal was filtered off and dried, whereby 3-amino-5-t-butylpyrazole (Compound (A)) 643 g (96.2%) was obtained. The melting point was 74.0 to 75.0° C.

来源