反应详情

A mixture of 1,1-dichloro-4-methylpenta-1,3-diene (15.1 parts), copper-containing catalyst in amount indicated in the table below and methanol (32 parts) is heated to reflux and ethyl bromocyanoacetate (19.2 parts) in methanol (14 parts) is then added at a uniform rate during 6 hours, and the acid-base balance ("pH" as indicated by a pH meter) is maintained at a predetermined value by the addition of a 13% solution of sodium methoxide in methanol. On completion of the ethyl bromocyanoacetate addition, heating at reflux temperature is continued for a further 2 hours, maintaining the desired acid-base balance as necessary. The resulting solution is evaporated under reduced pressure to remove the solvent and the product is isolated as described in Examples 2-6 above. The yield, strength and composition of the ethyl 1-cyano-3-(2',2'-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylate obtained are given in the following table together with other reaction details:

1. additioncontaining catalyst in amount
2. temperatureis heated
3. temperatureto reflux
4. temperatureheating
5. temperatureat reflux temperature
6. temperaturemaintaining the desired acid-base balance as necessary
7. customThe resulting solution is evaporated under reduced pressure
8. customto remove the solvent
9. customthe product is isolated