DE1057112B - Process for the preparation of thionophosphonic acid esters - Google Patents

Description

The invention relates to a process for the preparation of thionophosphonic acid esters of the general formula Process for the preparation of thionophosphonic acid esters

R - p:

, OR '

O —Alk —S-R "

in which R stands for an alkyl or phenyl radical which is optionally chlorinated in the p-position, R 'for a is lower alkyl and R "is an alkyl, aralkyl or aryl radical and Alk is an alkylene radical stands, characterized in that corresponding thionophosphonic acid ester halides with appropriately substituted mercaptoalkanols in the presence of acid-binding Funds are implemented.

The reaction is carried out in the presence of acid-binding agents, which have proven themselves above all here tertiary amines to bind the released hydrochloric acid. The use of organic solvents, such as B. benzene, toluene, acetone, chloroform and the like, have been used to carry out the Reaction proven to be beneficial. In order to achieve favorable results, the reaction is first carried out appropriately at low temperatures and then terminates the reaction at room temperature or at slightly elevated temperature.

The new thionophosphonic acid esters are effective Pesticides, some of which are characterized by a remarkably low toxicity. Partially they work against eating insects, which gives them an even wider range of uses given is. The new compounds are used in the way that is better known for phosphoric acid insecticides Kind of usual way, d. H. in connection with common solid or liquid extenders or thinners.

From "Angewandte Chemie", 1957, No. 3, pp. 88/89, it is already known to react dialkylthionophosphoric acid chlorides with alkylthioethanols to form phosphorus compounds which have the group —O — CH ₂ CH ₂ SR on phosphorus. Compared to such known compounds, which instead of a phosphonic acid ester group have an analogous phosphoric acid ester group, the former compounds are distinguished by a better insecticidal activity. These were compared

Applicant:

Paint factories Bayer Aktiengesellschaft, Leverkusen-Bayerwerk

Dr. Hanshelmut Sdilör, Wuppertal-Barmen, Dr. Ernst Schegk, Wuppertal-Elberfeld,

and Dr. Gerhard Sdirader, Wuppertal-Cronenberg, have been named as inventors

C ₂ H ₆ O,

CH _S O

PO CH ₂ CH ₂ SC ₂ H ₅ II

(known connection of the »Systox« type)

in their action against aphids, spider mites and mosquito larvae.

Solutions of these compounds were prepared by mixing the active ingredients in twice the amount Dimethylformamide and the same amount of a commercially available aromatic type emulsifier Polyglycol ethers and further dilution of these mixtures with water to that given below Concentration. The aphid experiments were carried out on French beans, the spider mite experiments on Bush beans and the experiments with mosquito larvae in the aqueous solution itself. The evaluation was at Aphids and spider mites after 8 days, in mosquito larvae after 24 hours. The results are summarized in the following table.

C ₂ H ₅ O,

CH,

; P -O CH ₂ -CH ₂ SC ₂ H ₅ I.

So

(Example 5 of the present application)

Ver
binding I Compound II 100
0 Solution. ° / o mortification 100
0 Aphids 0.01
0.001 100
100 100
0 0.01
0.001 100
100 909 510/487 Spider mites .... 0.005
0.001 100
100 Mosquito larvae ...

Claims (2)

The present invention is illustrated by the following examples:. y example 1 - CH ₂ -CH ₂ - SC ₂ H ₆ To 53 g / 3-thioethylethanol (V ₂ MoI) dissolved in 40 ecm anhydrous pyridine and 50 ecm chloroform, 103 g of methylthionophosphonic acid methyl ester chloride (boiling point 98 to 99 ° C) are added with stirring at 5 to 15 ° C ). The mixture is stirred for a further 2 hours at room temperature and the batch is then poured onto 100 g of ice to which 2 ecm of concentrated hydrochloric acid have been added. It is diluted with 200 ecm of benzene, washed twice with 100 ecm of water each time, separated off and the resulting solution is dried with it. Sodium sulfate. 116 g of the new ester are obtained as a pale yellow, water-insoluble oil. Yield 84 ° / ₀ of theory. Oral toxicity rat 150 mg / kg. 0.1 "solutions have a systemic effect on aphids. Example 2 0-CH ₂ -CH ₂ -SC ₂ H ₆ OC ₂ H ₅ 49 g / 5-thioethylethanol are dissolved in 37 g of anhydrous pyridine and 50 ecm of chloroform. While stirring, 102 g of phenylthionophosphonic _{acid ethyl ester chloride (boiling point 1>} 5,104 to 106 ° C.) are added dropwise at 5 to 15 ° C. and the mixture is stirred for a further 2 to 4 hours at room temperature. Then, as indicated in Example 1, work up. 116 g of the new ester are obtained as a colorless, water-insoluble oil. Yield 86% of theory. Oral toxicity rat 500 mg / kg. 0.17 solutions have a 100% systemic effect on aphids. Example 3 Cl- i , 0CH ₂ CH ₂ SC ₂ H ₅ OCH = To 20 g (0.2 mol) / 5-thioethylethanol, 20 ecm benzene, 1 cc of water, 33 g potassium carbonate and ¹ J ₂ g of copper powder is allowed to at room temperature, 51 cc (0.2 mol) of p-Chlorphenylthionophosphonsäureäthylesterchlorid (Kp. _3130-132 ° C) in 30 minutes dropwise. One stirs 2 days at 20 to 30 ° C, add 50 ecm of water and a little kieselguhr, suction, wash with dilute ammonia water and then with water, separate, dry and distill off the solvent in vacuo. The residue is kept at a bath temperature of 60 ° C. under a pressure of 1 mm. Yield 35 g = 54 ° / _c of theory. Oral toxicity rat 100 mg / kg. O, l% igc solutions killing aphids 100 ° / ₀ ig from. Example 4 0-CH ₂ -CH ₂ -SC ₂ H ₅ OCH, 48 g of ρ - chlorophenyl - thionophosphonic acid - methyl ester chloride (b.p. ₂ 125 to 128 ° C. ). The mixture is stirred for 2 days at room temperature and then worked up as indicated in the previous example. Yield 33g = 53 ° / ₀ "Theory. Oral toxicity rat 25mg / kg. 0.1% solutions kill aphids and caterpillars 100%. 0.01 "/" weight solutions act ig abtötend on spider mites 100 ° / _0th Example 5 c, H _s s-Ch ₂ -CH, o - p: , OC ₂ H, CH, 22 g (0.2 mol) of ß-thioethylethanol are dissolved together with 16 g (0.2 mol) of pyridine in 200 ecm of benzene and 34 g (slightly more than 0.2 mol) of methylthionophosphonic acid are added to this solution at 0 to 20 ° C -O-ethyl ester chloride was added dropwise. After brief heating to 60 ° C. and prolonged standing at room temperature, the pyridinium chloride is filtered off with suction, shaken with ice water to which a few drops of concentrated hydrochloric acid have been added, the benzene layer is separated off, dried over sodium sulfate and the solvent is removed in vacuo. 45 g of the new ester are obtained as a colorless liquid. In a high vacuum, the substance boils under a pressure of 0.01 mm at 63 ° C. Density: α * $ = 1.114. Refraction: n'g = 1.5040. Toxicity rat per os dl ₅₀ 25 mg / kg. O, l ° / _O by weight solutions kill the aphids to ^100% -Spinnmilben be reliably killed even with concentrations which comprise 0.01 ° / ₀ of the ester. In addition, the preparation shows a pronounced systemic effect. P A T K N T A N S P K U C H: Process for the preparation of thionophosphonic acid esters of the general formula , OR ' R —P: - Alk —S-R " in which R represents an alkyl radical or, if appropriate, phenyl radical chlorinated in the p-position, R 'represents a is lower alkyl and R "is an alkyl, aralkyl or aryl radical and Alk is an alkylene radical stands, characterized in that corresponding thionophosphonic acid ester halides with corresponding substituted mercaptoalkanols are reacted in the presence of acid-binding agents. ' Considered publications:
"Angewandte Chemie", 1957, pp. 88/89. 510 / Φ87 5.5 »