SU325850A1 - Method of producing cyclohexyl esters of di-alkylthio-phosphoric acids - Google Patents

Description

The invention relates to the preparation of the esters of Thiophosphoric acid, namely not described, in the literature of the cyclohexyl esters of dialkylthiophosphoric acids of the general formula

(R0bp-o:

chk

where R is alkyl,

R is hydrogen or alkyl.

These compounds have a strong acaricidal effect with relatively low toxicity for warm-blooded animals, as well as insecticidal and bactericidal activity.

The proposed method is based on the well-known esterification reaction of phosphorus acid chlorides with debris. The introduction of dichlorothiophosphoric acid chlorides and cyclohexanols into this reaction allows one to obtain new compounds that, by their acarcidal activity, are significantly superior to the known phosphorus esters.

The method is that dialkyl thiophosphoric acid chlorides are reacted with cyclohexanols in the presence of a hydrogen chloride acceptor, for example, a tertiary amine. The process is preferably carried out in an inert organic solvent, for example tetrahydrofuran.

The reaction goes well with the comedian temperature. The desired products are obtained in high yield and are isolated from the reaction mixture by well-known applications. As acaricides, they can be used without additional purification. The starting materials are readily available substances.

When M er. In a flask with a stirrer, a thermometer, a reflux condenser and a dropping funnel, 10 g (0.1 g-mol) of cyclohexanol, 10.1 g (0.1 g-mol) of trinethylamine, 100 ml of tetragidrofuran are added, and

acid chloride O, O-dnmetiltiofophornuyu acid. The reaction mixture is stirred at room temperature for 8-10 hours. The triethylamine hydrochloride is then filtered off, the tetrahydrofuran is distilled off, and the unreacted starting materials are removed in vacuo.

Cyclohexyl ester of dimethylthiophosphoric acid is obtained with a yield of 98%;

Lo 1.5050; dl ° 1.1470; MRn is calculated 56.48;

found 57.28.

Found,%: P 13.01. Calculated,%: P 13.83.

If the product is distilled in a vacuum, it is isomerized into OS-dimethyl-cyclohexylthiophosphate, which by acaricidal activity is inferior to the cyclohexyl effect of dimethylthiophosphoric acid. . The acaricidal effect of the drug was studied on ticks with Hyalom1ma apatolicum using the topical method, while its acute toxicity was detected during oral administration to white mice. The results indicate that this drug is 4-8 times more effective than chlorophos, although its toxicity to warm-blooded animals is less than that of chlorophos 10 (LDB 800-1200 mg / kg). The subject matter of the invention 1. A method for producing cyclohexyl esters of dialkylthiophosphoric acids of general formula 4 (RO) 2P-0 and p S where R is apkyl, R is hydrogen or alkyl, from which it is dialkylthiophosphoric acids subjected to interaction with cyclohexanol1 in the presence of an acceptor of hydrogen chloride with the following selection of the target product by known methods. 2. ipoosoo on and. 1, characterized in that the process is carried out in an inert organic solvent, for example tetrahydrofuran.