DE830509C - Process for the preparation of neutral esters of thiophosphoric acid - Google Patents

Description

It has been found that neutral esters of thiophosphoric acid are obtained when compounds the general formula:

Cl- alkyl - S-R

with alkali dialkyl thiophosphates. In the formula given, R stands for an alkyl, aryl or aralkyl radical. The alkali dialkyl thiophosphates used for the reaction react in the present Case in the tautomeric form 2 given below:

Alkyl O
»5 alkyl Cr

Alkyl CK
Alkyl O

.0

^ S —Na

(T. W. Mastin, G. R. Norman and E. A. Weilmuenster, Journal of the American Chemical Society, vol. 67 [1945], pp. 1662 to 1664) so that in this reaction, thiophosphoric acid esters are formed.

The reaction of the chlorides characterized above by the general formula with the alkali as salts of dialkylthiophosphoric acid can in the presence of inert solvents, eg. B. benzene, Toluene, chlorobenzene, can be made; also are for the implementation as a solvent but also very good ketones, ζ. Methyl ethyl ketone, methyl propyl ketone and others are suitable.

The new compounds obtainable by the process are characterized by and excellent contact insecticidal effects chemotherapeutic effects on the living plant.

example 1

7 g of finely powdered sodium are suspended in 100 ecm of toluene. Add 43 g at 40 ⁰

Diethyl phosphite. The temperature of 40 ⁰ is held for _{2 hours.} The sodium has then dissolved. Is then added with stirring to the reaction product, 10 g sulfur at 6o ° and heated for 1 hour at 105 ^0th To the now present in suspension Natriumdiäthylthiophosphat allowed at 55 ⁰ 34 g Chlormethyläthylsulfid (Reports of the German Chemical Society, Vol. 69, [1936], p 1612) interact. The temperature of the reaction mixture is kept at 55 ° for 1 hour, then 8 ecm of water is added to dissolve the resulting sailze, the toluene layer is lifted and it is fractionated. 40 g of the new ester are obtained. Yield corresponding to 60% of theory. The new thioester is insoluble in water and boiling under a pressure of 1.5 mm Hg at 129-130 ^0th

Example 2

As in Example 1, the finely divided sodium diethyl thiophosphate is prepared from the same amounts by weight. 52 g of chloromethyl-4-methylphenyl sulfide are added to this suspension (reports from the German Chemical Society, vol. 69 [1936], p. 1612). The reaction mixture is heated to 105 ° for 4 hours; the resulting salts are then brought into a filterable form with 10 ecm of water, the toluene layer is separated off and fractionated. 60 g of the new thioester with a boiling point of 0.5 178 ^{0 are obtained,} corresponding to a yield of 65%. The new substance is a water-insoluble, colorless oil.

Example 3

As in Example 1, the sodium diethyl thiophosphate is prepared from the same amounts. To the salt is added with stirring at 70 ⁰ 37 g / J-Chloräthyläthylsulfid (Liebigs Annalen der Chemie, Vol. 240 [1887], p 310). Heating the reaction mixture then for 2 hours at 150 ⁰ and removed as in the previous examples, the salts with water. When the toluene layer is fractionated, 54 g of the new thioester are obtained, corresponding to a yield of 70%.

The new ester is a water-insoluble, colorless oil that boils ^{at 132 to 133 0 under a pressure of 1 mm.}

Similarly, e.g. B. the following connection can be established:

QH ₅ O.

C ₂ H ₅ O '

.0

S-

C- * ΓΙ 2

O · 0 ΓΙ ο

Kp ₂ 134 °

Example 4

7 g of sodium powder are suspended in 100 ecm of toluene. To this are added 42 g of diisopropyl phosphite at 50 ^° and heated until the sodium has dissolved. Then one adds 9 grams of sulfur and heated for 1 hour at 90 to 95 ^0th It is then cooled to ⁰ and 50 can at this temperature for 37 S ß-Chloräthyläthylsulfid added dropwise. The reaction product is then held still with stirring for 4 hours at 90 to 95 ^0th The resulting salts are then converted into a filterable form by adding 5 ecm of water. After the salts have been filtered off with suction, the toluene solution is freed from the solvent. The remaining crude product is kept under a pressure of 2 mm at an internal temperature of 120 ° for 10 minutes in order to remove the residues of the volatile solvents. The new ester is obtained in this way as a brown-yellow, water-insoluble oil (60 g). At a pressure of 2 mm Hg, the EsteT can only be distilled with severe decomposition.

Claims (1)

Claim-. Process for the production of neutral esters of thiophosphoric acid, characterized in that that Alkalidialkylthiophosphate with compounds of the general formula Cl-alkyl —S — R, in which R is an alkyl, aryl or aralkyl radical, are reacted.