US2890237A - O-lower alkyl-o-(phenyl-mercapto-alkyl)-o-(beta, beta-dichlorovinyl)-phosphates - Google Patents

Description

hired State LOWER ALKYL O (PHENYL-MERCAPTQ-AL KYL)-0-(fl,fl-DICHLOROVlNYI)-PHOSPHATES Karl Zeile and Richard Sehring, Ingelheim, Germany, assignors to C. H. Boehringer Sohn, Ingelheim, Germany, a partnership No Drawing. Application May 1, 1958 Serial No. 732,147

Claims priority, application Germany November 22, 1956 6 Claims. (Cl. 260-461) This is a continuation-in-part of application Serial No. 698,067, filed November 22, 1957.

This invention relates to organic phosphoric acid esters, and more particularly to compounds having the general structural formula wherein R, n, R, and R have the meaning indicated in connection with Formula I and R is lower alkyl, to a condensation reaction with chloral (trichloroacetaldehyde).

The following examples illustrate methods of preparing various representative compounds of the broad class disclosed herein.

Example I.O-mezhyl-O-(p-chlorophenyl-mercaptoethyl) -O- (flfi-dichlorovinyl) phosphate 56 gm. (0.2 mol) 0,0-dimeth.yl-O-(p-chlorophenylmercaptoethyl)ephosphite were dissolved in 200 ml. toluene, and then 29.4 gm. (0.2 mol) chloral were added dropwise to the solution at C. The resulting mixinc ture was heated for 1 hour at 50 C. to make the reaction go to completion. Thereafter, the toluene solvent was distilled off, leaving behind a colorless, non-distillable oil. The yield was 72 gm., which corresponds to 95.5% of the theoretical yield.

Example II.-O-ethyl-O-(p-chlorophenyl-mercaptoethyl) -O-(l l -dichlorovinyl) -ph0sphate 61.6 gm. (0.2 mol) 0,0-diethyl-O-(p-chlorophenylmercaptoethyl)-phosphite were dissolved in 200 ml. toluene, and then 29.4 gm. (0.2 mol) chloral were added dropwise to the solution at 20 C. The resulting ture was heated for 1 hour at 50 C. to make the reaction go to completion. Thereafter, the toluene solvent was distilled ofi, leaving behind a colorless, non-distillable oil. The yield was 75.0 gm., which corresponds to 96% of the theoretical yield.

Example I II .O-methy'l-O- phenyl-mereaptoethyl 0- (,ILfi-dichlorovz'nyl) -ph0sphate 49.2 gm. (0.2 mol) 0,0-dimethyl-O-(pheny1-mercaptoethyD-phosphite were dissolved in 200 ml. benzene, and then 29.5 gm. (0.2 mol) chloral were added dropwise to the solution at 20 C. The resulting mixture was heated for 1 hour at 50 C. to make the reaction go to completion. Thereafter, the benzene solvent was distilled off, leaving behind a colorless, non-distillable oil. The yield was 67 gm., which corresponds to 97.5% of the theoretical yield.

Example I V.-O-methyl-0- p-tolyl-mercaptoethyl O- ([3,5-dichlorovinyl) -phosphate 52 gm. (0.2 mol) 0,0-dimethyl-O-(p-tolyl-mercapto ethyl)-phosphite were dissolved in 200 ml. ether, and 29.5 gm. (0.2 mol) chloral were added dropwise to the solution at 20 C. The resulting reaction mixture was then refluxed for 1 /2 hours to make the reaction go to completion. Thereafter, the ether was distilled oil, leaving behind a colorless non-distillable oil. The yield was 68 gm., which corresponds to of the theoretical yield.

We have found that the phosphoric acid esters according to the present invention having the structural Formula I above are powerful insecticides and acaricides. Moreover, they remain fully effective for extended periods of time and, as compared to phosphoric acid .esters of similar structure, exhibit an extremely low toxicity toward warm-blooded animals.

The following table shows the effectiveness and toxicity of some phosphoric acid esters according to the present invention in comparison to a known compound of similar structure. The LD -values in this table were determined by peroral administration of the respective compounds to white mice.

TABLE Cone, Percent Phosphoric Acid Ester LD percent Test Animal of Test Compound mgm. by Animals Weight Killed (l) CH:O O

0.05 Cockroaches 95 P 50 0.01 Flies 100 0.02 Red spiders 30 (EH O CH=O Cl, 0- ca s O 0. 100 A a is i3)..." OHSO O p 0. 05 Cockroaches 100' P 600 0. 01 Flies 100 0. 02 Bed spiders 98 TQHO O CH=C 01,

The acaricidal properties of the compounds according to the present invention and their prolonged effective duration in comparison to known compounds of similar structure can best be illustrated by the following comparative test:

Bean plants were sprayed with a spray containing 0.05% by weight of compound 2 in the above table, i.e. O ethyl O (p chlorophenyl mercaptoethyl) O- (p,fl-dichlorovinyl)-phosphate, and eight days later red spiders were released on the sprayed plants. 8590% of thered spider's died within a short period of time. The same results were obtained when a spray containing compound 3 in the above table was used to spray the bean plants.

In contrast thereto, when bean plants were sprayed with a spray containing 0.05% by weight 0,0-dimethyl- 1,2-dicarboxyethyl-dithiophosphate and red spiders were released on the sprayed plants eight days later, only of the red spiders died within a comparable period of time.

For insecticidal and acaricidal use, the organic phosphoric acid esters according to the present invention are advantageously admixed with inert carriers. The following examples illustrate various forms of insecticidal and acaricidal compositions which may be compounded with the aid of the phosphoric acid esters herein disclosed.

Example V.Dusting powder Two parts by weight phosphoric acid ester having Formula I above are admixed with 98 parts by weight kaolin, and the mixture is milled until homogeneous.

Example VI.-Suspension Ten parts by weight phosphoric acid ester having Formula I above are admixed with ten parts by weight naphthalene sodium sulfonate and 80 parts by weight kaolin. The mixture is milled until homogeneous and, prior to use, diluted with 50 to 200 liters water, depending upon the strength desired.

Example VII.Em:ulsi0n Fifty parts by weight phosphoric acid ester having Formula I above are dissolved in parts by weight ricinoleic acid butyl ester sulfonate, and the solution is admixed with 15 parts by weight xylene. The resulting solution is emulsified in a suitable quantity of water and is then diluted with 250 to 1000 liters of water just prior to use.

Example VIIL-Spray Five parts by weight phosphoric acid ester having Formula I above are dissolved in 95 parts by Weight petroleum ether.

Example IX .Aeros0l Five parts by weight phosphoric acid ester having Formula I above are dissolved in 95 parts by weight difiuorodichloromethane, and the solution is put into an aerosol dispenser.

While we have disclosed certain specific embodiments of our invention, it is understood that we do not wish to limit ourselves to these embodiments, and it will be readily apparent to others skilled in the art that the active insecticidal and acaricidal agents disclosed herein may also be employed in conjunction with known pesticidal agents.

Moreover, various other changes and modifications may be made without departing from the spirit of the invention or the scope of the appended claims.

We claim:

1. Organic phosphoric acid esters having the general R structural formula v O-(pp-diohlorovinyl)-phosphate.

4. 0 methyl O (phenyl mcrcaptoethyl) O (f3, ,B-dichlorovinyl)-phosphate.

5. O methyl O (p tolyl mercaptoethyl) 0-- (;8,fl-dichlorovinyl)-phosphate.

6. An insecticidal and acaricidal composition comprising at least 0.01% by weight of an organic phosphoric acid ester having the structural formula (R) wherein R is selected from the group consisting of hydrogen and halogen, n is an integer from 1 to 5, inclusive, R is alkylene with l to 6 carbon atoms, and R is lower alkyl, as the active insecticidal and acaricidal ingredient.

No references cited.

Claims (1)

1. ORGANIC PHOSPHORIC ACID ESTERS HAVING THE GENERAL STRUCTURAL FORMULA