DE1099535B - Process for the preparation of alkyl or aryl dithiophosphonic acid anhydrides - Google Patents

Description

Dithiophosphonic anhydrides of the general formula

R-P = S

Method of manufacture
of alkyl or aryl dithiophosphonic anhydrides

a complex compound of aluminum chloride, phosphorus trichloride and ethyl chloride, ethyl dithiophosphonic anhydride to win:

Applicant:

Leverkusen-Bayerwerk

C ₂ H ₅ -P-Cl ₄ -Al-Cl ₃ + 2H ₂ S
S.

Il

> C ₂ H ₅ -P = S + 4HCl + AlCl ₃

It is also known that by adding phosphorus pentasulfide alkenyl-dithiophosphonic anhydrides are formed on olefins (see P. Fay and H. P. Lankelma, Journal of the American Chemical Society, Vol. 74, 1952, p. 4933).

In addition, it is described in the literature that when adding phosphorus pentasulfide to aromatic Hydrocarbons, such as benzene, naphthalene, or anisole, aromatic dithiophosphonic anhydrides are formed (See U.S. Patent 2,870,204).

The specified preparation methods for dithiophosphonic anhydrides are all cumbersome and usually run with the formation of undesirable by-products.

It has now been found that aliphatic or aromatic dithiophosphonic anhydrides can be obtained in a surprisingly simple manner can be obtained by using the readily available alkyl or aryl thionophosphonic acid dichlorides Reacts with hydrogen sulfide at a higher temperature. It then arise in quantitative Yield dithiophosphonic anhydrides, e.g. B. according to the equation:

Dr. Reimer Colin, Wuppertal-Vohwinkel,
and Dr. Dr. hc Gerhard Schrader,

Wuppertal-Cronenberg,
have been named as inventors

The alkyl or aryldithiophosphonic anhydrides which are easily accessible industrially by the present process are very reactive compounds that are used as fungicides, but mainly as intermediates used in the manufacture of insecticides or as additives to lubricating oils.

The following examples illustrate the process.

example 1
S.

r> c

χ - ο

Xl

CH ₃ -P ^

+ H ₂ S

CH ₃ -P = S + 2HCl

'Cl

This clearly proceeding conversion of the alkyl or Arylthionophosphonsäuredichloride with hydrogen sulfide could not be foreseen, because the similar The reaction of alkyl or aryl phosphonic acid dichlorides and hydrogen sulfide is different.

Passing in 600 g of boiling methyl-thionophosphonsäuredichlorid with stirring under reflux for as long as anhydrous hydrogen sulphide, is increased until the temperature of the reaction mixture from 141 to 170 ⁰ C. The hydrogen chloride formed during the reaction is diverted. After the reaction mixture has reached a temperature of 170 ⁰ C, it is allowed to cool, whereby the methyl dithiophosphonsäureanhydrid crystallizes, which is filtered off. So much methyl thionophosphonic acid dichloride is added to the filtrate that the mixture is 600 g. Methyl dithiophosphonic anhydride is then prepared again by the method described above.

The filtered methyl dithiophosphonic anhydride is washed with carbon tetrachloride and dried in vacuo. Each obtained approach 120 to 150 g of methyl dithiophosphonsäureanhydrid whose melting point is above 250 ⁰ C.

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I 099

Molecular weight 110.1.

Calculated ... P 28.1%, S 58.2%;
found ... P 28.1%, S 58.5%.

The implementation can also be carried out continuously.

Example 2
S.

- P = S

500 g of ethyl thionophosphonic acid dichloride are under Stir and reflux heated to 150 to 160 ° C and bubbled into the solution of anhydrous hydrogen sulfide. The hydrogen chloride formed during the reaction is removed. After about 7 hours, the reaction product is allowed to cool. The precipitated ethyl dithiophosphonic anhydride is filtered off and washed with carbon tetrachloride. After drying in vacuo, 226 g of ethyl dithiophosphonic anhydride are obtained. Since 129 g of ethyl thionophosphonic acid dichloride were recovered in this approach, is the yield of ethyl dithiophosphonic anhydride 80% of theory, m.p. = 120 to 130 ° C.

Molecular weight 124.2.

Calculated ...
found ...

P 24.9 »/ ο, S 51.6%;
P 24.9%, S 51.2%.

Example 3
S.

isoC, H ₇ - P = S

35

P = S

543 g of cyclohexyl-thionophosphonic acid dichloride are passed at 155 ° C. with stirring 6 hours of anhydrous hydrogen sulfide. After the

ίο solution crystallizes the formed cyclohexyl-dithiophosphonic anhydride. The crystals obtained are washed with carbon tetrachloride and dried at 80 ^° C. in a vacuum. 96 g of the dithiophosphonic anhydride are obtained. Since 393 g of the starting compound were not reacted in the experiment, the yield of dithio compound is
Melting point 140-155 ° C.

Molecular weight 178.2.

Calculated ... P 17.3%, S 35.9%;
found ... P 17.0%, S 34.4 ° / ₀ .

78% of theory.

246 g of isopropyl thionophosphonsäuredichlorid are heated with stirring and refluxing to 160 ⁰ C, and the solution is passed about 8 hours, anhydrous hydrogen sulfide. Upon cooling, the mixture isopropyl dithiophosphonsäureanhydrid crystallizes out, which was filtered off, washed with carbon tetrachloride and dried in vacuo at 8O ⁰ C. 82 g of isopropyl-dithiophosphonic anhydride with a melting point of 145 ° to 158 ° C. are obtained. Since 139 g of the starting compound have been recovered, the anhydride yield is 90% of theory.

Molecular weight 138.2.

Calculated ... P 22.4%, S 46.4%;

found ... P 22.1%, S 45.1%. Hydrogen sulfide is introduced into 153 g of phenylthionophosphonic acid dichloride at 170 ° C. for 4 hours. When the solution cools, the phenyl-dithiophosphonic anhydride formed crystallizes out, which is filtered off with suction and washed with carbon tetrachloride. This gives 83 g of yellow crystalline phenyl-dithiophosphon anhydride melting point of 165 to 18O ⁰ C. The yield is 92% of the theoretically possible amount.

Molecular weight 172.2.

Calculated ... P 17.9%, S 37.2%;
found ... P 18.0%, S 37.4%.

When the filtrate is worked up, 41.5 g of unreacted starting compound are obtained back.

Claims (1)

PATENT CLAIM: Process for the preparation of alkyl or aryldithiophosphonic anhydrides, characterized in that alkyl or aryl thionophosphonic acid dichlorides are reacted with hydrogen sulfide at a higher temperature. © 109 510/452 2.61