CH616430A5 - Process for preparing organic esters of phosphorus - Google Patents

Description

The invention relates to a method for producing organic esters of phosphorus of the formula I specified in claim 1. The method according to the invention is defined in claim 1, while claims 22 and 23 define modifications of this method.

From Bull. Soc. Chim. France 1966 (3), pp. 932-937 it is known that alkyl halides react with tetramethylammonium salts of diesters of phosphoric acid and monoesters of phosphorous acid to triesters of phosphoric acid or diesters of phosphonic acid. The yields in which these two compounds are obtained are usually moderate and occasionally very low. Compared to this prior art, it has now been found that significantly better yields can be obtained if the alkyl halide is replaced by another alkylating agent.

In the process according to the invention, the yield of compounds of the general formula I is usually very high and can even be more than 95%.

The process can be carried out in the absence or, preferably, in the presence of a solvent. Examples of suitable solvents are aliphatic hydrocarbons such as pentanes, hexanes, heptanes, octanes, nonanes, decanes and mixtures thereof, e.g. Petroleum ether; cycloaliphatic hydrocarbons, such as cyclohexane, cycloctane, decalin; aromatic hydrocarbons such as benzene, toluene, xylenes and tetralin; Ketones such as acetone, methyl isobutyl ketone, 2-hexanone and 3-hexanone; Alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; chlorinated hydrocarbons such as chloroform, methylene chloride, 1,2-dichloroethane, chlorobenzene and o-, m- and p-di-chlorobenzene; nitrated hydrocarbons such as nitromethane, nitroethane, 1-nitropropane and nitrobenzene; Nitriles such as acetonitrile; N, N-dimethylformamide, dimethyl sulfoxide and tetramethylene sulfone. Mixtures of two or more of these solvents can be used, e.g. Mixtures of one or more aromatic hydrocarbons and chlorinated hydrocarbons. Very good results have been obtained with aromatic hydrocarbons, N, N-dimethylformamide, chlorinated aliphatic hydrocarbons and ketones.

It is advisable to choose the salts of the acids of the general formula II, the di (cyclo) alkyl sulfates of the general formula III and the solvents in such a way that the process proceeds in a homogeneous medium. This goal can generally be achieved by using quaternary onium salts of nitrogen, phosphorus, arsenic or

616430

4th

Antimony - in which the atoms of these four elements are bonded to four substituted or unsubstituted hydrocarbon groups - or tertiary onium salts of sulfur, selenium or tellurium - in which the atoms of these three elements are bonded to three substituted or unsubstituted hydrocarbon groups. The hydrocarbon groups are preferably unsubstituted. Very high yields of compounds of general formula I were obtained with tetrahydrocarbylammonium salts of the acids of formula II. The hydrocarbon groups can e.g. Alkyl groups (optionally substituted with cycloalkyl and / or aryl groups), cycloalkyl groups (optionally substituted with alkyl and / or aromatic groups) or aromatic groups (optionally substituted with alkyl and / or cycloalkyl groups). Among the tetrahydrocarbylammonium salts, the best ones have proven to be the tetraalkylammonium salts, which lead to excellent yields, in particular if they have at least three alkyl groups with more than one carbon atom per group. Examples of particularly suitable tetraalkylammonium salts are: methyltriethylammonium salts, methyltri-n-propylammonium salts and methylethyl-n-propyl-n-butylammonium salts. Excellent results have been obtained with methyltriethylammonium salts.

Examples of suitable tertiary onium salts are: triethyl-sulfonium salts, di-sec-decylmethylsulfonium salts, n-hexa-decyldimethylsulfonium salts, sec-dodecyl-sec. butylmethylsulfonium salts.

Other examples of salts of acids of general formula II are salts of secondary and tertiary amines, but they generally lead to low yields of esters of general formula I compared to quaternary onium salts. These yields are usually even lower when ammonium salts of acids of general formula II can be used.

The salts of the acids of general formula II can be metal salts, e.g. Salts of alkali or alkaline earth metals, i.e. Lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium or barium. Among them, the potassium, rubidium and cesium salts are preferred.

Particularly suitable as starting salts of acids of the general formula II are those in which (a) R1 represents a substituted vinyl group which is represented by the general formula

- 0 - C = C - R6 '4 1 5

R * R (IV)

wherein R4 represents a hydrogen atom, a methyl group or a phenyl group, which optionally carries one or more substituents, while Rn represents a hydrogen, chlorine or bromine atom and R ° represents a chlorine or bromine atom or one of the following groups: an alkyl group with 1 to 5 carbon atoms, an alkoxycarbonyl group with 1 to 10 carbon atoms, a "- (Ci-Cr, alkyl) benzyloxycarbononyl group, a C (0) -0-CH (C1-C5-alkyl) phenyl or a substituted carbamoyl group C (0 ) -NR7R8, wherein R7 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms and R8 represents an alkyl group having 1 to 5 carbon atoms; and in which (b) R2 in formula I represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 10 carbon atoms.

Examples of substituents when R4 represents a phenyl group are fluorine, chlorine and bromine atoms, e.g. are present in 2,4- or 2,5-dichlorophenyl or 2,4,5-trichlorophenyl groups, cyano groups and alkoxy groups, such as 5 methoxy and ethoxy groups. R6 can e.g. an a-methyl-benzyloxycarbonyl group, such as C (0) -0-CH (CH, 3) -CcH5, or a substituted carbamoyl group, such as N-methylcarbamoyl, C (0) -NH (CHl3), or N, N-dimethylcarbamoyl , C (0) -N- (CHa) 2.

10 In a particularly useful class of starting salts, R4 represents a hydrogen atom and R ° represents a chlorine or bromine atom, especially chlorine, while R5 can also be hydrogen. Very good results were obtained when R5 and Re each represent a chlorine atom.

15 In another very suitable class of starting salts of acids of the general formula II, R1 represents a substituted phenyl group of the general formula

20 - 0 - C = C - C (0) - NR7RÖ

CH-, H 3

where R7 and R8 have the above meaning.

25 Examples of such starting salts that have proven particularly useful are those in which R7 represents a hydrogen atom or a methyl group and R8 represents a methyl group.

A particularly suitable class of starting salts 30 of acids of the general formula II includes those in which R4 represents an optionally substituted phenyl group and R6 represents a chlorine or bromine atom or a Cr to C5-alkyl group. Excellent results can be obtained, for example, when R4 represents a halogenated, preferably chlorinated, phenyl group, especially 2,4-dichlorophenyl, 2,5-dichlorophenyl or 2,4,5-trichlorophenyl. One of the substituents Rn and R ° or both preferably represent a chlorine atom. If only one of them represents chlorine, R5 is preferably a hydrogen atom. Another, very well-suited class of initial salts of the acids according to formula II includes those in which R4 (see formula IV) represents a methyl group, R5 represents a hydrogen atom and R ° represents a methoxycarbonyl group.

For the salts of the acids according to formula II, R2 can e.g. 45 represents a methyl, ethyl, ethoxy or preferably a methoxy group.

Examples of suitable dialkyl sulfates according to the general formula III are dimethyl sulfate, diethyl sulfate, dipropyl sulfate, di-3-chloropropyl sulfate, dibutyl sulfate, dipentyl sulfate, 50-dihexyl sulfate, diheptyl sulfate, dioctyl sulfate, dinonylyl sulfate sulfate, dinonylyl sulfate sulfate . Very good results have been obtained with diethyl sulfate.

The process according to the invention proved to be particularly useful for the production of various substituted vinyl esters of acids of phosphorus with improved biocide properties, in particular insecticide, acaricid and / or anthelmintic properties.

Examples of particularly useful organic phosphorus esters of the general formula I, as are obtained according to the invention using diethyl sulfate as a compound of the general formula III, are: methyl ethyl [2-chloro-l- (2,4,5 -trichlorphenyl)] - vinyl phosphate; Methyl ethyl- [2-chloro-1 - (2,4-dichlorophenyl)] vinyl phosphate; Me-65 ethyl 2,2-dichlorovinyl phosphate; Methyl ethyl (l-methyl - 2-N-methylcarbamoyl) vinyl phosphate, methyl n-butyl 2,2-dichlorovinyl phosphate and methyl n-butyl- [2-chloro-l- (2,4-dichlorophenyl) ] vinyl phosphate.

5

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Generally speaking, reaction temperatures of 5 to 100 ° C. have proven to be very suitable, the temperature range from 40 to 75 ° C. being generally preferred, since the selectivity of the compound of the formula I is generally the highest here and the reaction of the salts of acids of the general formula II is very high, as is the yield of compounds of the general formula I. The selectivity in mol% for a particular compound is defined here as the number of moles of the salt of the acid according to formula II which special compounds were converted, multiplied by 100 and divided by the total number of moles of this salt converted. The yield of a particular compound is therefore the selectivity for that compound, multiplied by the percentage conversion of this salt of the acid according to Formula II and divided by 100.

In the reaction of the salt of the acid according to formula II and the compound according to formula III, the molar ratio of II: III is not critical and can vary within wide limits. However, it is advisable to keep this molar ratio at a value of less than 1, since at values of more than 1 the conversion of the salt is correspondingly low. It can be said that molar ratios of II: III between 1: 1 and 1: 1.5 are very expedient and in many cases the compounds of formula I are obtained in high yield at molar ratios of 1: 1 and 1: 1.2.

The resulting compound of formula I can be isolated from the reaction mixture in any way. The unreacted salt of the acid of the formula II is expediently extracted with water, the raffinate phase obtained is dried and the solvent and the unreacted compound of the formula III are distilled off. The residue remaining in the distillation usually contains the compound of the formula I in an amount of 90 to 95%. Among the solvents suitable for the process according to the invention, those which are immiscible with water are preferred since they enable the reaction mixture to be extracted with water. Toluene has proven particularly useful as a solvent.

The process according to the invention can be carried out by stirring a warm solution which contains the salt of the acid of the formula II and the compound of the formula III, the stirring time being e.g. 1} ^ to 5 hours. Quaternary ammonium salts of the acids according to Formula II, in turn, are also easily formed, e.g. by reacting a methyl ester of an acid of formula II with a tertiary amine, preferably in the presence of a solvent. One method therefore consists in the reaction of a compound of the general formula

R1 _ p _ o - cn3 (

n o

wherein R1 and R2 have the meaning given above, with a tertiary amine or one of its hydrohalides, the salt of the acid of the formula II formed in the reaction mixture then being reacted with a compound of the general formula III, in which, however, R "does not represent the methyl group .

Alkali or alkaline earth salts of the acids of formula II are also easily formed, e.g. by reacting a compound of formula V with an alkali or earth alkali thiocyanate, it being convenient to work in the presence of a solvent. Another process according to the invention therefore consists in reacting a compound of the general formula V with a thiocyanate of an alkali metal or alkaline earth metal salt, whereupon the alkali metal or alkaline earth metal salt of the acid of formula II formed is immediately mixed with a compound of the general formula in the reaction mixture Formula III implements. An advantage of this latter embodiment is the very high purity, e.g. 98-99%, in which the compounds of formula I are usually obtained.

The examples serve to explain the invention in more detail. In each example, data is provided on the reaction of a trihydrocarbyl phosphate with an amine or a salt to a dihydrocarbyl phosphate and on the reaction of this dihydrocarbyl phosphate with an alkylating agent to a trihydrocarbyl phosphate which is different from that which served as the starting material. Both reactions were carried out in a stirred reaction mixture. The data given include the reactants and their amounts, the solvent and its amounts and the reaction temperatures and times. In Tables I to V, the part to the left of the dashed vertical dividing line relates to the conversion of the starting material, trihydrocarbyl phosphate, and the part to the right of the dividing line relates to the conversion of the dihydrocarbyl phosphate. Dimethyl-2-chloro-1- (2,4-di-chlorophenyl) vinyl phosphate was used as the starting trihydrocarbyl phosphate, which is referred to below as "Compound I" and has a purity of 99%. After the reaction with the alkylating agent, the solvent was stripped off - unless toluene was used as the solvent - and 70 ml of toluene were added to the distillation residue obtained. The unreacted dihydrocarbyl phosphate was separated from the toluene-containing liquid by extracting three times with 50 ml of water each. The raffinate phase thus formed was separated from the extract phase, dried over sodium sulfate and subjected to distillation under a pressure of 0.0013 bar in order to drive off the toluene. Finally, the content of the product trihydrocarbyl phosphate in the distillation residue was determined. This percentage in% is referred to in tables I to V as “purity”.

example 1

In experiments 1 to 7, 0.100 mol of compound I was reacted with 0.105 mol of triethylamine using various solvents and the temperature being kept at 60.degree. there was obtained methyl-triethylammoniummethyl-2-chloro-l- (2,4-dichlorophenyl) vinyl phosphate, referred to below as “compound II”.

After completion of the reaction in experiments 1, 2, 3, 5 and 7, the solvent was abs under a pressure of 0.02 bar. aborted. In experiment 4, the solvent was left in solution. Experiments 8 to 14 were then carried out, in which the residues formed in experiments 1 to 3 and 5 to 7 and the solution from experiment 4 were mixed with 0.110 mol of diethyl sulfate. 40 ml of N, N-dimethylformamide were added to the distillation residue from experiment 1. The acetone present at the start of Experiment 11 was distilled off when the diethyl sulfate was added. The reaction mixture experienced a significant drop in viscosity during the reaction with diethyl sulfate. Table I shows the other relevant values, the degree of conversion of compound I, the selectivities to methyl ethyl 2-chloro-l- (2,4-dichlorophenyl) vinylphosphate (referred to below as “compound III”) and diethyI-2 -chIor-l- (2,4-dichlorophenyl) vinyl phosphate, referred to below as “Compound IV”.

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

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6

The reaction time specified for the reaction with diethyl sulfate comprises half an hour for the addition of the diethyl sulfate.

TABLE I

Vers. No.

solvent

Amount of solvent

Stirring time (h)

Vers. No.

Temp. (° C)

Response time (h)

Implementation (%)

Selectivity (%) according to compound III IV

Purity of compound III '(%)

1

toluene

40

3rd

8th

65

19th

93.8

94.1

<1.1

92.1

2nd

N, N-dimethylformamide

40

3rd

9

80

2nd

94.7

91.3

6.4

87.9

3rd

1,2-dichloroethane

40

3rd

10th

80

2nd

96.9

94.8

2.1

90.6

4th

acetone

40

3rd

11

80

2.5

83.7

95.7

0.8

80

5

toluene

40

5

12

80

2.5

87.5

94.1

4.9

81.5

6

0

2.5

13

80

1.75

96.5

90.0

7.8

84.7

7

toluene

5

3rd

14

60

2nd

97.0

97.3

2.7

92.4

Example 2

In experiments 1 to 7, the compound I was reacted with triethylamine in the presence of 15% of its weight of toluene. The reaction mixtures formed in experiments 1 to 4 were reacted with diethyl sulfate and the mixture from experiment 5 with di-n-butyl sulfate.

Table II shows the other relevant data; the indicated reaction times include one hour for the addition of triethylamine and diethyl sulfate. The table also shows the degree of conversion for compound I, 35, the selectivities for compounds III and IV and the degree of purity of compound III.

TABLE II

Vers. No.

Amount in moles of compound I

Triethylamine

Temp. (° C)

Response time (h)

Vers. No.

Diethyl sulfate mol

Temp. (° C)

reaction time

(H)

Implementation (%)

Selectivity (%) according to compound III IV

Purity of connection

III (% by weight)

1

0.667

0.700

70

2nd

8th

0.733

50

4th

98.4

95.3

2.0

92.8

2nd

0.0905

0.095

70

2nd

9

0.095

50

4.5

97.1

96.3

3.7

93.9

3rd

0.100

0.105

60

2nd

10th

0.110

90

1.75

92.4

85.7

10.3

80.0

4th

0.100

0.105

90

1

11

0.110

60

2nd

99.3

95.3

1.5

94.5

Di-n-butyl

sulfate

5

0.0700

0.0735

50

5.5

12

0.0735

50

5

94

95

3rd

79.5

Mol

In experiments 1 to 10, 0.100 mol of the compound was reacted with various bases in the presence of 15% of its weight of toluene. Since the tetramethylammonium methyl 2-chloro-l- (2,4-di-chlorophenyl) vinyl phosphate formed in experiment 2 is only slightly soluble in the reaction mixture, 15 ml of N, N-dimethylformamide were added in order to redissolve the precipitated phosphate and that To make the mixture more mixable. In experiment 8, a precipitate precipitated out, so that the reaction mixture hardly

60 was still to stir. 5 ml of toluene and 25 ml of N, N-dimethylformamide were therefore added. Experiments 9 and 10 were started in the presence of 40 ml of N, N-dimethylformamide or 70 ml of toluene. The precipitates 65 present at the end of experiments 18 to 20 were filtered off before the solvent was driven off. The other relevant data are shown in Table III. The reaction times are half an hour for the addition of the base and the diethyl sulfate. Out

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Table III also shows the degree of conversion of compound I, the selectivity towards compounds III and IV and the degree of purity of compound III.

TABLE III

Vers. No.

base

Reac

Molation temp. Base time (° C) (H)

M „1 Reak- TIm SdSität Purity

Diägyl Temp. Tions- ^ bindu ^ g

(h) (%) (%) 111

1

2nd

3rd

4th

5

Triethylamine 0.105 0.105

Trimethylamine

Tri-n-propyl amine

Dimethyl aniline

Triethanolamine

0.105 0.105 0.105

3rd

5

6 5

90 70 70 70-90 70

11 0.110 60

99.3 95.2 1.5 94.5

12 0.110 50 4 100 86.0 0.2 93.9

13 0.105 50 4 87.1 96.7 3.3 83.4

14 0.105 70 4 50.7 94.4 2.2 48.1

15 0.105 50

89.2 52.8 0 75.9

Example 4

30th

In experiments 1 to 3, 0.1 mol of compound I was reacted with various salts in the presence of 20 ml of N, N-dimethylformamide. Table IV shows the other relevant data and reaction conditions. The time to react with diethyl sulfate is 20 minutes to add the sulfate. Table IV also shows the degree of conversion for compound I, the selectivity towards compounds III and IV and the degree of purity of compound III.

TABLE IV

Vers. No.

salt

Reac

Mol temp. Salt (° C) time

(H)

Mol

Convert selectivity (%) return

Vers. Alkylation temp.

No. medium middle (° c) z? It Z /%? Connection ^ bin-

Mean * ^ XI (%);, 7U1U ^ dung (h) 111 1V III (%)

KSCN

0.105 90

11 diethyl 0.105 60 5% 99.8 83.5 sulfate

94.9

KSCN

Triethylamine hydrochloride

0.105 60 0.105 70

12 16

0.105 60 5% 99.3 89.7 0.7

0.105 70 5 ^ 99

76

0.8

98.5 97.4

Example 5

In experiments 1 to 5, various dimethylphosphates were reacted with 0.105 mol of triethylamine, in experiments 1 to 3 in the presence of 15 ml and in experiment 5 by 5 ml of toluene and in experiment 4 in the presence of 20 ml of N, N- Dimethylformamide, while in experiment 6 0.0735 mol triethylamine and 5 ml toluene were used. The reaction mixtures formed in experiments 1, 2, 4 and 5 were reacted with 0.105 mol of di-

60 ethyl sulfate, the reaction mixture from experiment 6 with 0.073 mol of diethyl sulfate and that from experiment 3 with 0.105 mol of hexyl bromide. Table V shows the other relevant data and reaction conditions; the reaction time is half an hour for the addition of 65 triethylamine and diethyl sulfate. Table V also shows the degree of conversion of the starting dimethyl phosphate and the yield and the degree of purity of the corresponding methyl ethyl phosphate.

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8th

TABLE V

Vers. No.

Starting dimethyl phosphate

Mol

Starting phosphate

Temp. (° C)

Response time (h)

Vers. No.

Temp. (° C)

Response time (h)

Methyl ethyl phosphate (obtained)

Yield Purity (%) (%)

1

Dimethyl-1- (2,4,5-trichlorophenyl) -2-chlorovinylphosphate

0.100

70

6

50

4M

> 90

> 90

2nd

Dimethyl 2,2-dichloro vinyl phosphate

0.100

50

4th

7

50

4K

90

90

3rd

»

0.100

50

5

8th*)

50 and then 80

5 and then%

5

35

4th

Dimethyl- [1-methyl - 2- (N -methylcarbamoyl) vinyl phosphate

0.110

50

4K

9

50

6

> 85

> 40

5

Dimethyl-1-methyl-

-2-methoxycarbonyl-

vinyl phosphate

0.100

50

5K

10th

50

SM

> 85

90

6

Dimethyl 2,2-dichloro vinyl phosphate

0.070

50

5 H

11

50

sy2

86

74.6

*) not according to the invention

Claims (20)

61643 « ,1 R! R '- p - OH ii 0 (II) 1 R1 _ p "0 - CH- 0 (V) 60 wherein R1 and R2 have the above meaning, reacted with a thiocyanate of an alkali or alkaline earth metal, the alkali or alkaline earth metal salt thus formed salt of the acid of formula II 65 ,1 ir - P H 0 0 - R 45 (I) in which R1 is an optionally substituted hydrocarbyloxy group, R2 is an alkyl or alkoxy group or hydrogen and R3 is an alkyl, with the exception of methyl, or cycloalkyl group, characterized in that a compound of the general formula 2nd 50 55 R 2nd 2. The method according to claim 1, characterized in that a tetra-hydrocarbylammonium salt is used as the salt of the acid according to formula II. 2nd PATENT CLAIMS 1. Process for the preparation of organic esters of phosphorus of the formula R R t P h 0 - 0 - R- (I) wherein R1 is an optionally substituted hydrocarbyloxy group, Ra is an alkyl group or alkoxy group or hydrogen and R3 is an alkyl or cycloalkyl group, characterized in that a salt of an acid of the general formula R R i P - OH h 0 a substituted carbamoyl group, C (0) N-R7R8, where R7 is a hydrogen atom or an alkyl group having 1-5 C atoms and Rs is an alkyl group having 1-5 C atoms, and (b) R2 is an alkyl group with 1-5 C atoms or an alkoxy group with 1-10 C atoms. 3 II 3 R - 0 - S - 0 - R. 3rd 616 430 in which R1 is an optionally substituted hydrocarbyloxy group, R2 is an alkyl or alkoxy group or hydrogen and R3 is an alkyl, with the exception of methyl, or cycloalkyl group, characterized in that a compound of the general formula 5 R2 R - F - 0 - GH- 0 (V) wherein R1 and R2 are as defined above, reacted with a tertiary amine or its hydrohalide, the quaternary ammonium salt of the acid of the formula II formed R2 R1 - P Oll II 0 (II) left in the reaction mixture and there with a compound of general formula III 0 , il r 3 - 0 - S - 0 - R 0 25th 30th (HI) 35 is implemented, but R3 in formula III does not represent the methyl group. 23. Process for the preparation of organic esters 40 of the phosphorus of the formula R 3. The method according to claim 2, characterized in that a tetrahydrocarbylammonium salt is used as a tetraalkylammonium salt. 4th R6 R (IV) means in which R4 is a hydrogen atom, a methyl group or an optionally mono- or polysubstituted vinyl group, R5 is a hydrogen, chlorine or bromine atom and R ° is a chlorine or bromine atom or an alkyl group having 1 to 5 carbon atoms, an alkoxycarbonyl group with 1 to 10 carbon atoms, an a- (C1-C5-alkyl) benzyloxycar bonyl group, C (0) -0 - CH (C1-C5-alkyl) -phenyl, or in which R7 and Rs have the above meaning , represents. 4. The method according to claim 3, characterized in that one uses a tetraalkylammonium salt which has at least three alkyl groups with more than one carbon atom per group. 5. The method according to claim 4, characterized in that a methyltri-ethylammonium salt is used as the tetraalkylammonium salt. 6. The method according to claim 1, characterized in that a potassium, rubidium or cesium salt is used as the salt of the acid according to formula II. 7. The method according to claim 1, characterized in that a salt of an acid according to formula II is used, wherein in this general formula II (a) R1 is a substituted vinyl group of the general formula 0 - C » R ' 8. The method according to claim 7, characterized in that in the substituted vinyl group according to the general formula IV R4 is a hydrogen atom and R ° is a chlorine or bromine atom. io 9. The method according to claim 8, characterized in that each represents a chlorine atom in the substituted vinyl group according to formula IV Ra and Re. 10th left in the reaction mixture and then with a compound of the formula 0 10. The method according to claim 7, characterized in that in formula II R1 is a substituted vinyl group of the 15 general formula -0 ~ Ç = CH-C-NR7R8 CH0 0 20th (II) with a dialkyl or dicycloalkyl sulfate of the formula Rv - 0 - - 0 - R- (III) 0 implements. 11. The method according to claim 10, characterized in that R7 for a hydrogen atom or a methyl group 25 pe and R8 represent a methyl group. 12. The method according to claim 7, characterized in that R4 stands for an optionally substituted phenyl group and R6 for a chlorine or bromine atom or a Cj-Cr, -alkyl group. 30th 13. The method according to claim 12, characterized in that R4 stands for a halogenated phenyl group. 14. The method according to claim 13, characterized in that the halogenated phenyl group represented by R4 is a 2,4- or 2,5-dichlorophenyl or a 2,4,5-tri-chlorophenyl group. 15 II 0 (III) implements. 15. The method according to any one of claims 12 to 14, characterized in that R5 is a hydrogen or a chlorine atom and Rc is a chlorine atom. 16. The method according to claim 7, characterized in that R4 is a methyl group, R5 is a hydrogen atom and RG is a methoxycarbonyl group. 17. The method according to claim 7, characterized in that R2 represents a methoxy group. 18. The method according to claim 1, characterized in that diethyl sulfate is used as the dialkyl sulfate of the general formula III. 19. The method according to claim 1, characterized in that it is carried out at a temperature of 25-100 ° C, preferably from 40 to 75 ° C. 20. The method according to claim 1, characterized in that the salt of the acid of formula II and the compound of formula III are used at the beginning in a quantity ratio which corresponds to a molar ratio II: III between 1: 1 and 1: 1.5. 21. The method according to claim 1, characterized in that it is carried out in the presence of a water-immiscible solvent, preferably toluene. 22. Process for the preparation of organic esters of the phosphorus of the formula ~ II 35 40 45 50 55 K1 - 65 I. P II 0 - 0 - R 20th