CS258839B1 - Sulphone acids' salts mixture for pyrethroid insecticides preparation and method of its preparation - Google Patents

Abstract

A mixture of 3-phenoxybenzylsulfonic salts acids for the preparation of pyrethroid insecticides containing 1 to 99% wt. α-hydroxy-3-phenoxybenzylsulfonic acid acids of formula I and 1 to 99% wt. N- (2-hydroxyethoxy) -3-phenoxybenzylsulfonic acid acids of formula III, wherein M is an alkali metal cation. Way the preparation of this mixture is that it is to the cyclic acetal of 3-phenoxybenzaldehyde of formula II is treated with an alkali metal pyrosulfite metal, possibly prepared in situ, in the presence of at least an equimolar amount water in at least one water miscible an organic solvent, optionally in the presence of a phase transfer catalyst.

Description

The invention relates to a mixture of 3-phenoxybenzylsulfonic acids for the preparation of pyrethroid insecticidal compositions.

It is known that the alpha-hydroxy-3-phenoxybenzylsulfonic acid salts of the formula I in which M is an alkali metal cation are used in the synthesis of pyrethroid insecticidal compositions. Methods for their use are described, for example, in U.S. Pat. in EP 0 025 925 and Brit. 1 567 531

Various methods for preparing salts of formula I are also known. According to one method described in DE 2 951 496, a salt of formula I is prepared from a cyclic acetal of formula II by treatment with an acid sulfuric salt in the presence of water and one water-miscible organic solvent. The disadvantage of this process is the low stability of sodium bisulfite and hence the more difficult availability of pure alpha-hydroxy-3-phenoxybenzylsulfonic acid salt.

The above-mentioned disadvantages are overcome by the composition according to the invention, which contains 1 to 99 wt. % alpha-hydroxy-3-phenoxybenzylsulfonic acid salts of formula I and 1-99 wt. alpha (2-hydroxyethoxy) -3-phenoxybenzylsulfonic acid salts of the general formula III, wherein M is an alkali metal cation. Mixtures of salts of formulas I and III can be advantageously used in the preparation of pyrethroid insecticidal compositions as a synthetic equivalent of the pure salt of formula I. The pure salt of formula III also serves for this purpose equally well.

A mixture of the 3-phenoxybenzylsulfonic acid salts of formulas I and III can be prepared by the process of the invention, which comprises treating the 3-phenoxybenzaldehyde cyclic acetal II with alkali metal pyrosulphite, optionally prepared in situ, in the presence of at least one equivalent of water; at least one water-miscible organic solvent, optionally in the presence of a phase transfer catalyst.

The process according to the invention is generally carried out in a complicated heterogeneous environment.

At the beginning of the reaction, one or two liquid and one solid phase (crystalline anroganic salt) coexist. A new solid phase (a mixture of pigs of formula I and III) is then gradually formed during the reaction. As a result of this heterogeneity, the product composition often varies over a wide range in repeated experiments in terms of the ratio of salts of formulas I and III. When ethylene glycol is used as a solvent, however, the salt of formula III is usually predominant.

The composition of the mixture can be determined, for example, by pyrolytic decomposition. The determination is based on the finding that the salt of formula I by pyrolytic decomposition gives 3-phenoxybenzaldehyde, while the salt of formula III by pyrolysis provides the starting cyclic acetal of formula II. Thus, from the ratio of 3-phenoxybenzaldehyde to cyclic acetal of formula II in the distillate obtained by pyrolysis, the composition of the mixture of salts of formulas I and III can be determined.

The preparation of a mixture of salts according to the invention of the formulas I and III, the method of analysis and the use in the preparation of the pyrethroid insecticidal composition are explained in more detail in the following examples.

He did

Sodium salt of general formula I (M ⁺ - Na ⁺ ) and its pyrolytic decomposition

To a solution of 15.5 g of the cyclic acetal of formula II in 80 ml of ethanol was added a solution of 30 g of sodium sulfite in 80 ml of water. The mixture was heated at reflux for 24 h, after cooling the precipitated crystals were aspirated, washed with ethanol and dried, m.p. from 160 ° C (dec.).

For C 3,6^H, 10^OjSNa (302) calculated C 51.66, H 3.64, S 10.75;

Found: C, 50.37; H, 3.92; S, 10.20.

NMR Spectrum (DMSO-d6):? 6.7-7.6 (m, 9H, arom)} 6.0 (d, 1H, CH; J = 6 Hz); 5.02 (d,

1H, OH, J = 6Hz).

Pyrolytic decomposition: From 500 mg of the crystalline salt of formula I (M ⁺ = Na ⁺ ) placed in a flask, 350 mg of a liquid distillate consisting exclusively of 3-phenoxybenzaldehyde according to gas chromatography was obtained by heating in an oil pump vacuum at 100 to 180 ° C. .

Example 2

Sodium salt of formula III (M ⁺ = Na ⁺ ) and its pyrolytic decomposition

To 25 ml of dry ethylene glycol was added 0.18 ml of water, 3.82 g of sodium pyrosulfite, 4.82 g of the cyclic acetal of formula II and 0.2 g of tetraethylammonium bromide. The reaction mixture was heated at 60 ° C for 30 h, then cooled, allowed to stand for 12 h, the precipitated crystals were aspirated, washed with methanol and benzene, dried in a water pump vacuum. Yield 4.18 g of sodium salt of formula III, m.p. 125-140 ° C (dec.).

For C ₁₅ H ₁₅ O _g (SNA 346) calculated 52.02% C, 4.34% H, 9.25% Si Found 51.86% C, 4.12% H, 9.67% S.

NMR Spectrum (DMSO-d6): 6.85-7.6 (m, 9H, arom), 5.70 (s, 1H, CH), 4.41 (m, 1H, OH),

3.95 (m, 2H, O-CH2 ₎ ; 3.42 (m, 2H, -CH3OH).

Pyrolytic decomposition: From 350 mg of the sodium salt of formula III placed in a flask flask, heating under oil pump vacuum at 100-180 ° C yielded 230 mg of distillate, which according to gas chromatography is a uniform product, identical by elemental analysis, retention time and NMR cyclic acetal spectra of formula II.

Example 3

Mixture of salts of formulas I and III (M ⁺ = Na ⁺ )

To a solution of 15.5 g of the cyclic acetal of formula II in 150 ml of 50% aqueous methanol was added 24.46 g of sodium pyrosulfite. The mixture was heated at reflux for 24 h, after cooling, the precipitated crystals were aspirated, washed with methanol and benzene and dried. Yield 17 g; m.p. 160-180 ° C (dec.).

Pyrolysis: Under pyrolysis conditions of Example 1, 500 mg of a crystalline mixture of salts of formulas I and III yielded 350 mg of a liquid consisting of 10% cyclic acetal of formula II and 90% of 3-phenoxybenzaldehyde (glc).

Example

To a solution of 15.5 g of the cyclic acetal of formula II in 77 ml of methanol was added a solution of 24.46 g of sodium pyrosulfite in 77 ml of water. The mixture was stirred at room temperature for 2 h, whereupon crystalline product began to precipitate out of solution. The heterogeneous mixture was then heated to boiling for 24 hours, after cooling the crystals were aspirated, washed with methanol and benzene and dried. Yield 17 g; m.p. 140 DEG-160 DEG C. (dec.).

Pyrolysis: Under pyrolysis conditions of Example 1, 500 mg of crystalline salt yielded 350 mg of distillate consisting of 80% cyclic acetal of formula II and 20% 3-phenoxybenzaldehyde according to gas chromatography.

? example5

Use of a mixture of salts of formula I and III (M ⁺ «Na ⁺⁾ in the synthesis of pyrethroid insecticidal .icidu (alpha-cyano-3-phenoxybenzyl 3-) 2,2-dichlorovinyl) -2-dimethylcyclopropanecarboxylate _of 2)

0.18 g of a mixture of salts of formula I and III (about 1: 1) were stirred for 25 minutes with 98 mg of potassium cyanide and 67 mg of benzyltriethylammonium chloride in a two-phase system consisting of 0.5 ml of water and 1 ml of toluene. To the stirred mixture was then added 0.105 g of 3- (2,2-dichloro-vinyl) -2,2-dimethyl-cyclopropanecarboxylic acid chloride and the progress of the reaction was monitored by lyn chromatography. After 1 h the reaction was complete, the ester formed was isolated in 80% yield.

Claims (2)

A mixture of 3-phenoxybenzylsulfonic acid salts for the preparation of pyrethroid insecticidal compositions, characterized in that it consists of from 1 to 99% by weight of the composition. % alpha-hydroxy-3-phenoxybenzyl sulfonic acid of formula I, wherein M ⁺ is an alkali cation, and 1 to 99 wt. salts of alpha- (2-hydroxy-ethoxy) -3-phenoxybenzylsulfonic acid of the general formula III, where M ⁺ has the same meaning as in the formula I. 2. A process for the preparation of a salt mixture according to claim 1, characterized in that the cyclic acetal-phenoxybenzaldehyde of the formula II is treated with alkali metal pyrosulphite, optionally prepared by sewing, in the presence of at least equimolar amount of water in at least one water-miscible organic solvent. transmission.