1,1-dichloro-4-methylpenta-1,3-diene

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 30.6 g (0.2 mole) of 1,1-dichloro-4-methyl-1,3-pentadiene in 400 ml methylene chloride were added 0.35 mole of technical perchloroacetic acid containing 1.0 g sodium acetate at a temperature of 10°-20° C. over a period of 20 minutes. After stirring for 15 hours, the reaction mixture was poured into 500 ml of water. The phases were separated and the aqueous phase extracted twice with 150 ml of methylene chloride. The organic phases were combined and washed with 10% aqueous sodium carbonate (2×100 ml) and saturated aqueous sodium chloride (1×100 ml), dried over Na2SO4 and the solvent evaporated. The product was distilled to give 34 g of 1,1-dichloro-3,4-epoxy-4-methyl-1-pentene (82% yield). The phases were separated the aqueous phase extracted twice with 150 ml of methylene chloride washed with 10% aqueous sodium carbonate (2×100 ml) and saturated aqueous sodium chloride (1×100 ml) dried over Na2SO4 the solvent evaporated The product was distilled

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 30.6 g (0.2 mole) of 1,1-dichloro-4-methyl-1,3-pentadiene in 400 ml methylene chloride were added 0.35 mole of technical perchloroacetic acid containing 1.0 g sodium acetate at a temperature of 10°-20° C. over a period of 20 minutes. After stirring for 15 hours, the reaction mixture was poured into 500 ml of water. The phases were separated and the aqueous phase extracted twice with 150 ml of methylene chloride. The organic phases were combined and washed with 10% aqueous sodium carbonate (2×100 ml) and saturated aqueous sodium chloride (1×100 ml), dried over Na2SO4 and the solvent evaporated. The product was distilled to give 34 g of 1,1-dichloro-3,4-epoxy-4-methyl-1-pentene (82% yield). The phases were separated the aqueous phase extracted twice with 150 ml of methylene chloride washed with 10% aqueous sodium carbonate (2×100 ml) and saturated aqueous sodium chloride (1×100 ml) dried over Na2SO4 the solvent evaporated The product was distilled

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of ethyl cyanoacetate (12.44 parts), 1,1,3,4-tetrachloro-4-methylpent-1-ene (11.1 parts), 1,1-dichloro-4-methylpenta-1,3-diene (7.55 parts), cupric acetate H2O (2.0 parts) and in two cases lithium halide, in acetonitrile (100 parts by volume) is heated to reflux and held at 75°-80° C. for 6 hours. After cooling to room temperature the suspension is filtered and the residue is washed twice with acetonitrile (20 parts by volume). The combined filtrate and washes are distilled under reduced pressure to remove acetonitrile and the residue is extracted with a mixture of toluene (100 parts by volume), water (150 parts by volume) and concentrated hydrochloric acid (100 parts by volume). After filtering from extraneous matter the filtrates are separated and the toluene layer is washed twice with hydrochloric acid (50 parts by volume) diluted with water (50 parts) and finally four times with water (50 parts). The toluene is removed by distillation under reduced pressure to yield crude ethyl 1-cyano-3-(2',2'-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylate. Details are given in the following table: to reflux is filtered the residue is washed twice with acetonitrile (20 parts by volume) The combined filtrate and washes are distilled under reduced pressure to remove acetonitrile the residue is extracted with a mixture of toluene (100 parts by volume), water (150 parts by volume) and concentrated hydrochloric acid (100 parts by volume) After filtering from extraneous matter the filtrates are separated the toluene layer is washed twice with hydrochloric acid (50 parts by volume) diluted with water (50 parts) and finally four times with water (50 parts) The toluene is removed by distillation under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of ethyl cyanoacetate (24.88 parts), 1,1-dichloro-4-methylpenta-1,3-diene (30.2 parts) cupric chloride (2.68 parts), calcium carbonate (40 parts), calcium chloride and potassium bromide as indicated in the table below, is heated in water in the presence of a phase transfer catalyst (either cetyl trimethyl ammonium bromide (CTMAB) or methyl triethyl ammonium chloride (MTEAC)]]. Sodium hypochlorite solution, bromine or chlorine are then added at a uniform rate to the mixture at an elevated temperature. Heating is continued for a further period. After cooling the reaction mixture, the suspension is diluted with butyl acetate (100 parts by volume). Concentrated hydrochloric acid (50 parts by volume) diluted with water (100 parts) is slowly added, the mixture is stirred for about 30 minutes and then filtered to remove extraneous matter. The butyl acetate layer is separated and washed with water (4×50 parts). The butyl acetate is removed by distillation under reduced pressure to yield crude ethyl 1-cyano-3-(2',2'-dichlorovinyl)-2,2-dimethylcyclopropane -1-carboxylate. Details of the reaction conditions are given in the table below, together with the yield, strength and composition of the product. Heating is continued for a further period After cooling the reaction mixture is slowly added filtered to remove extraneous matter The butyl acetate layer is separated washed with water (4×50 parts) The butyl acetate is removed by distillation under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of ethyl cyanoacetate (12.44 parts), 1,1-dichloro-4-methylpenta-1,3diene (15.1 parts), lithium chloride monohydrate (6.26 parts), cupric acetate monohydrate, and in one case potassium acetate, as indicated in the table below, in acetonitrile (100 parts by volume), is heated and chlorine is added at a uniform rate, heating being continued for a further period. After cooling the reaction mixture the acetonitrile is removed by distillation under reduced pressure and the ethyl 1-cyano-3-(2',2'-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylate is isolated as described for Examples 41 to 48. The yield, strength and composition of the product, together with other preparative details, are given in the table below. is heated heating being continued for a further period is removed by distillation under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 1,1-dichloro-4-methylpenta-1,3-diene (30.2 parts), ethyl bromocyanoacetate (38.4 parts), calcium carbonate (20 parts), cuprous chloride (0.2 part) and calcium chloride (22.2 parts) in ethanol (100 parts by volume) is heated to reflux temperature and held at 78°-84° C. for 6 hours. The ethanol is distilled off under reduced pressure and the residue is stirred with a mixture of toluene (100 parts by volume), water (150 parts) and concentrated hydrochloric acid (100 parts by volume). The mixture is filtered from extraneous matter, the residue is washed with toluene and the filtrate and washings are combined. The toluene layer is separated and washed with water. The crude ethyl 1-cyano-3-(2',2'-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylate is isolated by removal of the toluene under reduced pressure. The product has a strength of 74.6% and a cis-cyano/trans-cyano ratio of 86.1:13.9. The yield is 68.7%. is heated to reflux temperature The ethanol is distilled off under reduced pressure The mixture is filtered from extraneous matter the residue is washed with toluene The toluene layer is separated washed with water