CS232630B1 - A method for separating crystalline salts from a solution of O.O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate - Google Patents

Abstract

The invention solves a method of removing crystalline salts from a solution of 0,0-dimethyl-0-(3-methyl-4-nitrophenyl)-2thiophosphate formed by condensation of 3-methyl-4-nitrophenol and/or its sodium salt with O,O-dimethylchlorothiophosphate in the presence of a hydrogen chloride binding agent. After condensation, the crystalline salts are dissolved in an aqueous solution of sodium 3-methyl-4-nitrophenolate or 3-methyl-4-nitrophenol containing mineral salts at a temperature preferably of 50 to 95°C. The content of organic compounds of phosphorus, sulfur, and/or chlorine and aromatic solvents is reduced in the aqueous solution by distillation, extraction, or adsorption. The invention can be used in the production of O,O-dimethyl-O-(3-methyl-4-nitrophenylthiophosate), which is most often used as an insecticide.

Description

The present invention provides a method for decrypting crystalline salts from a solution of O, O-dimethyl-O- (3-methyl-4-nitrophenyl) -2-thiophosphate formed by condensation of 3-methyl-4-nitrophenol and / or its sodium salt with O, O-dimethylchlorothiophosphate in presence of a hydrogen chloride binding agent.

After completion of the condensation, the crystalline salts are dissolved in an aqueous solution of sodium 3-methyl-4-nitrophenol or 3-methyl-4-nitrophenol containing mineral salts at a temperature of preferably 50 to 95 ° C. The aqueous solution reduces the content of organic phosphorus, sulfur, and / or chlorine compounds and aromatic solvents by distillation, extraction, or adsorption.

The invention can be used in the production of O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate, which is most commonly used as an insecticide.

232830

The invention relates to the separation of crystalline salts from a solution of O, O-dimethyl-O- (3-methyl-4-nitrophenol) thiophosphate formed by condensation of O, O-dimethylchlorothiophosphate with sodium 3-methyl-4-nitrophenolate or 3-methyl-4-nitrophenol and hydrogen chloride binding agent.

O, O-dimethyl-O- (3-methyl-4-nitrophenyl) (thiophosphate is used as an effective insecticide especially in agriculture. It is much less poisoned to warm-blooded animals than O, O-dimethyl-O- (4-nitrophenyl) Most often, O-dimethyl-O- (3-methyl-4-nitrophenylthiophosphate) is prepared by reacting O, O-dimethylchlorothiophosphate with 3-methyl-4-nitrophenol, in the presence of an acid binding agent or in the presence of a medium. e.g., U.S. Pat. No. 670,030 and Germany No. 814,297. French Pat No. 12,266,417 describes the preparation of O, O-dimethyl-O- (3-methyl-4-nitrophenyl) (thiophosphorus). by adding O, O-dimethyl chlorothiophosphate to a mixture of 3-methyl-4-nitrophenol, K 2 CO 3 and a powder medium in toluene, and the use of chlorobenzene as the reaction medium in French Pat No. 1 272 685. Condensation of O, O-dimethyl chlorothiophosphate with 3-methyl-4-nitrophenol in anhydrous acetone, methyl ketone in the presence of Na2CO3 at reflux temperature, U.S. Pat. .

520,393, brit. pat. no. 644 610, French. pat. no. 957 803. The preparation of Ο, --dialkyl - (- 4-nitrophenyl-1-thiophosphate by reaction of O, O-dialkylchlorothiophosphate with sodium 4-nitrophenolate in chlorobenzene, ethanol, or aqueous media is described in Fletcher J. Am. Chem. Soc. 70 3943 ( The preparation of O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate by the reaction of O, O-dimethylchlorothiophosphate with 3-methyl-4-nitrophenol is described in Schultz Berichte der deutschen Chem. Gesellschaft, 40 4322. O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate by reacting O, O-dimethylchlorothiophosphate with an alkali metal 3-methyl-4-nitrophenolate, or 3-methyl-4-nitrophenol in the presence of acid binding agents describes U.S. Pat. No. 89,124.

The insecticidal formulation of O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate and the process for its preparation by reacting O, O-dimethylchlorothiophosphate with 3-methyl-4-nitrophenol or its alkaline salt is described in Japan. U.S. Pat. 28 075 (1959) and no. 30,541 (1959); No. 1,116,790, U.S. Pat

091 565. Purification of organophosphorus pesticides of the general formula

RiO \

P-X-R _3/11

R 2 X X wherein R 1 and R 2 is C 1 -C 4 alkyl, X is O, or S and R 3 is aryl or aryl substituted with alkyl halogens or nitro, the impurities being distilled off with water vapor; pat. no. 129 591.

The preparation of O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate according to US Pat. Nos. 89,124 and 129,591, wherein water is azeotropically distilled off during the reaction, is described in US AO No. 211,804. O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate by reacting 3-methyl-4-nitrophenol with O, O-dimethylchlorothiophosphate in the presence of K 2 CO 3 in methyl ethyl ketone, cooling the reaction mixture and filtering off with suction. Schrader, Die Entwieklung neuer Insectizider Phosphorsaiire Ester, Verlag Chemie GMBH Weinheim p. 293 (1963).

In the above references, little attention is paid to separating the prepared solution of O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate from unreacted or reaction-formed salts.

The above drawbacks are eliminated by the method of separating the crystalline salts from the O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate solution, which comprises adding O, O- to the solution to dissolve the crystalline salts. dimethyl chlorothiophosphate with sodium 3-methyl-4-nitrophenolate aqueous solution of sodium 3-methyl-4-nitrophenolate concentration up to

3.5% by weight, or an aqueous solution of 3-methyl-4-nitrophenol at a concentration of up to 2000 mg / L.

The aqueous solutions contain mineral salts at concentrations up to 30% by weight. The volume ratio of the aqueous solution to the solution of O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate is 0.05: 1 to 5: 1.

The aqueous solution of sodium 3-methyl-4-nitrophenolate or 3-methyl-4-nitrophenol contains mineral salts, aromatic hydrocarbon at a concentration of 0.01 to 1% by weight, organic phosphate, sulfur and / or chlorine compounds.

The sodium 3-methyl-4-nitrophenolate solution is used at a temperature of 5 to 105 ° C, preferably at 50 to 95 ° C.

The aqueous solution is subjected to distillation or adsorption after dissolution of the crystalline salts to reduce the content of organic compounds of phosphorus, sulfur and / or chlorine and aromatic hydrocarbons.

The aqueous solution, after dissolving the crystalline salts to reduce the content of organic phosphorus, sulfur and / or chlorine compounds, is subjected to extraction with organic water-insoluble compounds, preferably aromatic hydrocarbons.

According to the process of the present invention, an O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate aqueous solution containing sodium 3-methyl-4-nitrophenolate can be obtained. dissolved organic compounds of phosphorus, sulfur and / or chlorine, and organic solvents, can be removed, more preferably using closed apparatuses. Multiple repetitions of the process of the present invention can provide solutions of 3-methyl-4-nitrophenolate at a concentration of 30-40%. According to the process of the present invention, a significant amount of waste water is lost in the production of O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate, which is substantially reduced therein. content of phenol derivatives, thereby improving the environment The apparatus for carrying out the invention is undemanding and simple.

Example 1

A three-necked flask equipped with a stirrer, a thermometer and a separatory funnel was charged with 500 ml of toluene, 75 g of 77.1 wt. Sodium 3-methyl-4-nitrophenolate, 10 g K 2 CO 3. The mixture was heated to gentle boiling. 180 ml of 30.5% w / w was added via addition funnel to the reaction mixture. toluene solution of O, O-dimethylchlorothiophosphate. The reaction mixture was kept under gentle boiling for 6 hours. After completion of the reaction, 200 ml of a 15 ° C aqueous solution containing 0.09% by weight of 3-methyl-4-nitrophenol and 5.1% Na 2 SO 4 were added to the reaction mixture. After dissolution of the salts, the aqueous layer was separated from toluene. The aqueous layer contained 12.4 g of sodium 3-methyl-4-nitrophenolate, 0.12 g of toluene and an organic compound of phosphorus, sulfur and chlorine, which was determined to be organic P of 0.13 grams, S was 0.11 g Cl was 0.02 g.

Example 2

The procedure of Example 1 was followed except that, after completion of the reaction, 10 ml of water was added to the reaction mixture and the toluene solution was separated from the crystallized salts which were mostly adhered to the walls of the flask. The aqueous layer from the experiment described in Example 1 was then added to the reaction flask. After dissolving the crystalline salts, the aqueous solution contained 26.3 g of sodium 3-methyl-4-nitrophenolate.

Example 3

The procedure of Example 2 was followed except that the aqueous solution of Example 2 was used except that its temperature was 95 ° C. The crystallized salts dissolved more rapidly than in the previous examples. The aqueous solution after dissolution of the crystalline salts contained 39.2 g of sodium 3-methyl-4-nitrophenolate and an organic compound of phosphorus, sulfur and chlorine expressed as organic P 0.17 g S 0.16 g and Cl 0.01 g. The aqueous solution was extracted with toluene (100 mL) for 2 times. After extraction, the content of organic phosphorus compounds expressed as organic P decreased to 0.04 g.

Example 4

The procedure of Example 3 was followed except that upon dissolution of the crystalline salts, 180 ml of an aqueous solution was obtained which contained 44.1 g of 3-methyl-4-nitrophenolate>

sodium and phosphorus organic compounds expressed as organic P 0.17 g and 0.14 g toluene. The solution was heated to 98-100 ° C. It was kept at this temperature for 3 hours. The aqueous solution contained 0.11 g of organic P and 0.03 g of toluene.

Example 5

The procedure of Example 4 was followed except that after dissolution of the crystalline salts, toluene and organic phosphorus and sulfur compounds were distilled from the aqueous solution by steam. With an unchanged volume of aqueous solution, the amount of condensed water was 130 g. After distilling off the water, the salt solution contained 0.02 g of organic phosphorus.

Example 6

Following the procedure of Example 1, 10 g of activated carbon were added to the solution after dissolution of the salt. After 5 hours, the activated carbon was filtered off. The amount of organic phosphorus was 0.01 g.

Example 7

The procedure of Example 1 was followed except that 200 ml of a 15 ° C aqueous solution containing 420 mg / 3-methyl-4-nitrophenol and 0.3% Na 2 CO 3 was added to the reaction mixture after completion of the reaction. After dissolution of the salts, the aqueous layer contained 12.9 g of sodium 3-methyl-4-nitrophenolate, 0.13 g of toluene, 0.09 g of organic phosphorus, 0.08 g of organic sulfur and 0.01 g of organic chlorine. Repeating the experiment twice gave an aqueous solution of sodium 3-methyl-4-nitrophenolate at a concentration of 29.4% by weight, the inorganic salts being 24.5% by weight. Sodium 3-methyl-4-nitrophenolate precipitated out of solution by cooling.

Example 8

The procedure of Example 1 was followed except that 50 ml of an aqueous emulsion containing 0.5% Na 2 CO 3, 0.2% toluene and 250 mg / L sodium 3-methyl-4-nitrophenolate were used to dissolve the salt. Some of the toluene was in the form of an emulsion. The temperature during the extraction was 95 ° C. After separation, the aqueous layer contained 13.2 g of sodium 3-methyl-4-nitrophenolate.

Example 9

The procedure of Example 1 was followed except that 2000 ml of an aqueous solution containing 50 mg / L of toluene and 710 mg / L of 3-methyl-4-nitrophenol were used to dissolve the salt. The temperature during the extraction was 3 to 5 ° C. After dissolution of the salt the aqueous solution contained

12.1 g of sodium 3-methyl-4-nitrophenolate.

The invention can be used in obtaining 2323230

Sodium 3-methyl-4-nitrophenolate which remains unreacted and is in crystalline form to produce O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate.

Claims (5)

232630 of sodium 3-methyl-4-nitrophenolate, which is unreacted and is in crystalline form, in the production of O, O-dimethyl-O- (3-methyl-4-nitrophenylthiophosphate). A method for separating crystalline salts from a solution of O, O-dimethyl-O- (3-methyl-4-nitrophenylthiophosphate prepared by reacting 0,0-dimethylchlorothiophosphate with sodium 3-methyl-4-nitrophenolate in the presence of a hydrogen chloride reagent, e.g. an aromatic hydrocarbon or hydrocarbon / water environment, wherein the aqueous solution of 3-methyl-4-nitrophenolate sodium is added to the solution to dissolve the crystalline salts after concentration to about 35% by weight; of methyl 4-nitrophenol, concentration of up to 2000 mg / l and mineral salts of up to 30% by weight, wherein the volume ratio of aqueous solution to O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate is 0.05: 1-5: 1. 2. A process as claimed in claim 1, wherein the aqueous solution of 3-methyl-4-nitrophenol sodium or 3-methyl-4-nitrophenol contains mineral salts, aromatic hydrocarbons having a concentration of 0.01. % to 1 wt. organic compounds of phosphorus, sulfur and / or chlorine. 3. Process according to claim 1, characterized in that an aqueous solution of 3-methyl- (4-nitrophenolate sodium at a temperature of 5 to 105 ° C, preferably at 50 to 95 ° C) is used. 4. A method according to clauses 1 and 3, characterized in that the aqueous solution of the dissolved crystalline salts is reduced to the content of organic phosphorus, sulfur and / or chlorine compounds and aromatic hydrocarbons by distillation or adsorption. 5. Process according to claim 1, wherein the aqueous solution of the soluble crystalline salts is subjected to extraction with organic, water-insoluble hydrocarbon-containing hydrocarbon compounds to reduce the content of organic phosphorus, sulfur and / or chlorine compounds. Severografla, n. P., Závod 7, Most Price 2,40 Kčs