JPS5921857B2 - 3 (2 2-dichlorovinyl) -2 2- dimethylcyclopropane carbonate ester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improved process for producing certain cyclopropane carboxylic acid esters useful as insecticides or insecticide intermediates.

In particular, the present invention provides 3(2.2-dichlorovinyl)-2.
The present invention relates to a method for producing esters of 2-dimethyl-cyclopropanecarboxylic acid. 3(2,2-dichlorovinyl)-
゛2.Processes for producing 2-dimethyl-cyclopropanecarboxylic acid and certain esters thereof are described by Farkes
[Coll, C2ech, Ch
em, Comm.

24, pp. 2230-2236, (1959)]. That is, ethyl ester can be produced by the reaction of ethyl diazoacetate and 1,1-dichloro-4-methyl-1,3-pentadiene. However, the method described in the above literature is a laboratory method for producing small quantities of the compound, and therefore, due to the inherent risks when using ethyl diazoacetate, the above method is not necessary for large-scale production. It is unsuitable for immediate scale-up. The present inventor has recently developed a method for producing 3(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid esters that is free from the potential dangers that exist when using diazoacetic acid esters.

According to the invention, therefore, (a) an ester of glycine in the form of a water-soluble acid addition salt and an alkali metal nitrite are combined in a first reaction vessel with 1,1-dichloro-4-methyl-1, The reaction is carried out in an aqueous medium in interfacial contact with a solvent having a boiling point lower than that of 3-pentadiene and which is immiscible with the aqueous medium but which preferentially dissolves the formed diazoacetic acid ester, and the formed diazoacetate is Transfer the acetate ester into the above solvent; (
b) an excess of 1,1-dichloro-4-methyl-1,3 maintained at a high enough temperature to readily distill off said solvent;
- a second reaction vessel containing pentadiene, wherein the diazoacetate is reacted with 1,1-dichloro-4-methyl-1,3-pentadiene and 3(2,2-dichlorovinyl)-2,2; - Containing the diazoacetic ester produced in step (a) in a second reaction vessel that also contains a catalyst that promotes the liberation of nitrogen from the initial reaction product of the reaction producing the ester of dimethylcyclopropanecarboxylic acid. and then (c) from the second reaction vessel a stream of 1,1-dichloro-4-methyl-1
・3-pentadiene and 3(2,2-dichlorovinyl)-
3(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid ester, characterized in that: removing a mixture of 2,2-dimethylcyclopropanecarboxylic acid with an ester and distilling the pentadiene from this mixture; A manufacturing method is provided.

In the method a) of the method of the present invention, the diazoacetate produced in the aqueous phase is freely soluble in the organic solvent but hardly soluble in the aqueous phase; The ester automatically migrates from the aqueous phase to the solvent phase at the interface between the two phases.

Therefore, no special means are required to transfer the dia-A sulfate to the solvent phase. The method of the present invention includes returning the solvent distilled from the second reaction vessel to the first reaction vessel and transferring the diene compound distilled from the reaction mixture taken out from the second reaction vessel to the second reaction vessel. Preferably, the operation is carried out continuously, in such a way that it is returned to the container.

The advantages of this method are: (a) the diazoacetate is produced, transported and decomposed in a closed reaction system, reducing the risk of contact with the diazoacetate by personnel operating the equipment; and (5) the amount of diazoacetate present in the reaction system is always small, thus reducing the risk of explosion due to premature and sudden decomposition of the diazoacetate. Solvents suitable for use in the process of the invention include saturated chlorinated hydrocarbon solvents such as dichloroethylene, dichloromethane, carbon tetrachloride, and the like.

The heating temperature of the contents of the second reaction vessel is suitably 60 to 150°C, preferably 100 to 130°C. Suitable catalysts for use in the second reaction vessel include copper-bronze; palladium salts, such as chloride or acetate; or rhodium salts, although other transition metals or salts may also be used.

Alkali metal nitrite salts which can be used in the present invention are, for example, potassium or sodium salts, and the reaction with the glycine ester is preferably carried out in the presence of an acid catalyst, for example sulfuric acid.

The method of the present invention uses various 3(2,2-dichlorovinyl)-
It can be used to make esters of 2,2-dimethylcyclopropanecarboxylic acid, and depending on the specific glycine ester used, specific carboxylic esters are obtained.

For example, the method of the invention may be used to produce simple alkyl esters useful as intermediates for making pesticides or to produce the pesticide itself. In the latter case, the glycine ester must correspond to the desired insecticidal ester. Examples of glycine esters of this type are 3-phenoxybenzyl alcohol and 5-benzyl-3
-Furyl ester with methanol. In order to make the present invention more clear, examples of the present invention will be shown below with reference to process diagrams of the present invention.

EXAMPLE This example describes the production of 3(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid ethyl ester.

Water (25 m
Glycine ethyl diester hydrochloride (27.97) in 0
A solution of sodium nitrite (15.2y) in water (20ml) was added to reactor 1 from A at a flow rate such that there was no excess of glycine ethyl ester hydrochloride relative to the sodium nitrite. was likewise added to reactor I from B at a flow rate such that sodium nitrite was not in excess relative to the hydrochloride.

These two aqueous solutions were mixed with each other to form an upper layer Q that was in interfacial contact with a lower layer R of 1.2 dichloroethane which had been previously charged into the reactor 1 from C. At this time, the temperature of the reactor was maintained at 5° C., and the aqueous solution was added in about 20 minutes. During this time, ethyl diazoacetate was formed in the upper aqueous layer, which was gently stirred, for example with a paddle stirrer, and transferred into solution in the lower solvent layer. After the reaction was completed, the aqueous solution used could be withdrawn from reactor 1 via D. Solvent (contains ethyl diazoacetate)
is continuously removed from reactor 1 via E and about 11
Excess 1,1-dichloro4-methyl-1,3-pentadiene (90.67) (previously charged from J) and copper bronze catalyst (4.07) charged from P kept at 5°C was charged into a reactor containing .

Under these conditions, the 1,2-dichloroethane solvent is immediately volatilized and its vapor passes through F to condenser 1.
The condensed solvent was returned to reactor 1 via G. Diazoacetic acid ethyl ester and the diene react to form an intermediate believed to be pyrazoline, which decomposes to liberate nitrogen and the desired 3(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarbonate. The ethyl ester of the acid was formed. The nitrogen evolved during this reaction was passed from the reactor via F into condenser 11 and exhausted via H. The mixture of reaction products and excess diene was transferred via K to the evaporator, where the distilled diene was passed via L to the condenser and then refluxed via M to the reactor. The crude product was removed from the evaporator via N. This crude product can be purified by distillation if necessary or used as an intermediate without purification.

[Brief explanation of the drawing]

The drawings are process diagrams showing the method of the present invention.

Claims (1)

[Claims] 1 (a) In a first reaction vessel, an ester of glycine in the form of a water-soluble acid addition salt and an alkali metal nitrite were mixed in a 1.1
- an aqueous medium that is brought into interfacial contact with a solvent that has a boiling point lower than the boiling point of dichloro-4-methyl-1,3-pentadiene and is immiscible with the aqueous medium but preferentially dissolves the formed diazoacetate; (b) an excess of 1,1-dichloro-4-methyl maintained at a high enough temperature to readily distill the solvent; -1
- A second reaction vessel containing 3-pentadiene, and diazoacetate and 1,1-dichloro-4-
Reacting with methyl-1,3-pentadiene gives 3(2,2
-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid.
a stream of solvent containing the diazoacetate produced in step (a) is continuously introduced into the reaction vessel;
) from the second reaction vessel a mixture of 1,1-dichloro-4-methyl-1,3-pentadiene and an ester of 3(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid; and distilling the pentadiene from this mixture;
A method for producing (dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid ester.