反应详情

20 g of dimethylacrylyl chloride, dissolved in 100 g of acetonitrile, are added to 20 g of 4-chloro-1-hydroxypyrazole, 20 g of sodium carbonate and 150 g of acetonitrile at 25° C., while stirring. Stirring is continued for 12 hours at 25° C., after which the solid product is filtered off under suction and washed with 100 g of acetonitrile. The solution is evaporated down at 40° C. and under 20 mbar, the residue is taked up in 200 g of dichloromethane, the solution is extracted 3 times with 200 g of saturated aqueous sodium bicarbonate solution, the organic phase is dried with magnesium sulfate and evaporated down, and the residue is digested with 300 g of petroleum ether. 30.5 g (90% of theory) of 4-chloropyrazol-1-yl 3,3-dimethylacrylate of melting point 71° C. are obtained.

1. stirringStirring
2. filtrationafter which the solid product is filtered off under suction
3. washwashed with 100 g of acetonitrile
4. customThe solution is evaporated down at 40° C. and under 20 mbar
5. extractionthe solution is extracted 3 times with 200 g of saturated aqueous sodium bicarbonate solution
6. dry with materialthe organic phase is dried with magnesium sulfate
7. customevaporated down