反应详情

A mixture of 1,1-dichloro-4-methylpenta-1,3-diene (15.1 parts) ethylbromocyanoacetate (19.2 parts), copper-containing catalyst (as indicated in the table below), acid binder (as indicated in the table below) in solvent (as indicated in the table below; 100 parts by volume) is heated to the reflux temperature of the mixture if below 90° C., otherwise at a temperature not exceeding 90° C., and held at the reaction temperature for 6 hours. After removal of the solvent by distillation under reduced pressure the residue is extracted with a mixture of toluene (100 parts by volume), water (150 parts) and concentrated hydrochloric acid (100 parts by volume). The extract is filtered, the toluene layer is separated, washed with water (4×50 parts) and the crude ethyl-1-cyano-3-(2',2'-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylate is isolated by distilling off the toluene under reduced pressure. The yield, strength and composition of the product obtained is given in the table below together with other reaction details.

1. additioncontaining catalyst (
2. temperature100 parts by volume) is heated to the reflux temperature of the mixture if below 90° C., otherwise at a temperature not
3. customexceeding 90° C.
4. customAfter removal of the solvent
5. distillationby distillation under reduced pressure the residue
6. extractionis extracted with a mixture of toluene (100 parts by volume), water (150 parts) and concentrated hydrochloric acid (100 parts by volume)
7. filtrationThe extract is filtered
8. customthe toluene layer is separated
9. washwashed with water (4×50 parts)