反応 #319200

反応方程式

2-(3-chloropropyl)-1,3-dioxolane

hydrogen

sodium hydride

methyl 1-hydroxypyrazole-4-carboxylate

→

Methyl 1-[3-(2-dioxolanyl)-propoxy]-pyrazole-4-carboxylate

溶媒

dimethylformamide

反応条件

後処理

1. 1
   workup.ADDITIONare added a little at a time to the stirred mixture
2. 2
   workup.WAITthe mixture is kept at 120° C. for 10 hours
3. 3
   workup.DISTILLATIONThereafter, the dimethylformamide is distilled off under reduced pressure
4. 4
   洗浄the solution is washed with water
5. 5
   その他evaporated down
6. 6
   その他to give 151 g of a slightly colored oil which
7. 7
   その他crystallizes completely

実験手順

21.8 g of sodium hydride (80 percent strength suspension in mineral oil) is introduced into 1.5 l of dry dimethylformamide, and 90 g of methyl 1-hydroxypyrazole-4-carboxylate are added a little at a time to the stirred mixture. When the evolution of hydrogen is complete, stirring is continued for 30 minutes, after which 95.5 g of 2-(3-chloropropyl)-1,3-dioxolane are added dropwise and the mixture is kept at 120° C. for 10 hours. Thereafter, the dimethylformamide is distilled off under reduced pressure, the residue is taken up in methyl tertbutyl ether, and the solution is washed with water, boiled and evaporated down to give 151 g of a slightly colored oil which crystallizes completely. M.p. 40°-42° C. NMR (CDCl3): 7.82 s [1]; 7.70 s [1]; 4.50 t [1]; 4.39 t [2]; 3.85-3.95 m [4]; 3.80 s [3]; 1.75-1.95 m [4].

出典