DE1252680B - Process for the preparation of phosphinic acid esters - Google Patents

Description

UNDESREPUBLIC OF GERMANY

j
GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

C07f

German class: 12 ο - 26/01

Number: 1 252 680

File number: M 66152IV b / 12 ο

Filing date: July 28, 1965

Opening day: October 26, 1967

This invention relates to an improved method for synthesizing phosphinic acid esters.

In the prior art it is known that phosphorus oxyhalides with Grignard reagents for Production tertiary phosphine oxides can be implemented. If tertiary phosphine oxides with different If residues are desired, phosphonyl halides can be used because of the substitution of some of the halogen atoms in the oxyhalide through organic radicals does not prevent the reaction from proceeding changes. It was also known that the conversion of phosphorus compounds which halogen atoms, aryloxy or contain alkoxy substituents, with a Grignard reagent the reaction proceeds as if only one substituent, namely halogen, is present, the corresponding tert-phosphine oxides being formed will. It is also known that in the case of the phenyl halophosphates, the reverse of the conventional Order in the addition of the reactants when using Grignard reagents, i.e. the Add the halide to the Grignard reagent, of little concern in terms of interference of the products received.

In contrast, the invention relates to a process for the preparation of phosphinic esters of the general formula

R ¹ Z - P (R ² ) _a

by reacting a phosphoric acid ester chloride of the general formula

Process for the production of
Phosphinic acid esters

(R ¹ Z) _7n PCl ^

Applicant:

Monsanto Company, St. Louis, Mo. (V. St. A.)

Representative:

Dr. W. Berg and Dipl.-Ing. O. Stapf,

Patent Attorneys, Munich 2, Hilblestr. 20th

Named as inventor:

Kurt Alois Nowotny, Rock Hill, Mon. (V. St. A.)

Claimed priority:

V. St. v. America July 29, 1964 (386 077) - -

gives, the reaction mixture is allowed to cool, acidified, then washed neutral and the product in the usual Way isolated.

Examples of R ¹ are tolyl, xylyl, tert-butylphenyl, octylphenyl, dodecylphenyl or propoxyphenyl as well as methyl, ethyl, isopropyl, sec-butyl, tert-butyl, octyl and dodecyl.

a5 In addition to the oxygen-containing ones, sulfur-containing phosphinic acid esters of the general formulas

(1) 35 and

with an organometallic compound of the general formula

R ² MX (11)

where in the formulas R ^{1 is} a phenyl, alkyl, alkoxyphenyl, alkylphenyl or naphthyl radical with in each case 1 to 12 carbon atoms in the alkyl or alkoxy radical, Y and Z are oxygen or sulfur, m and η are 1 or 2, where m and η together is 3, R ^{2 is} an aryl, alkyl or alkaryl radical each having 1 to 12 carbon atoms in the alkyl radical, M is magnesium, aluminum, sodium or lithium and X is bromine or chlorine, which is characterized in that a solution of the organometallic compound II in approximately twice the molar amount per mole of 1 is added dropwise to the solution of the phosphoric acid ester chloride 1 at reflux temperature, while stirring

Ri G - P - (rak S.
Il Ri - O Il
- P - (R ₂ ) ₂ S.
Il Ri - S. Il
- P - (R ₂ ) ₂

produce.

Such phosphinic acid esters have excellent properties as herbicides, insecticides and bio-eids as well as intermediate products therefor and as functional fluids, especially hydraulic fluids, on.

In general, when carrying out the process according to the invention, one proceeds Standard glass reaction vessel equipped with a stirrer, a reflux condenser, raw material inlet, Product outlet, heating means and thermometer charged with a phosphoric acid ester halide, which is used in Solvents that are used to carry out Grignard

709 679/586

Reactions are useful, such as aliphatic or cyclic ethers, or inert hydrocarbons is dissolved. The Grignard compound is added dropwise in a suitable solvent with the stirrer running. If about two times the molar amount of the organometallic compound with respect to the Phosphorsäureesterhalogenid added and the reaction is completed, the mixture is allowed to stand for at least 1 hour at room temperature and then treated with a sufficient amount of 10 ° / ₀ hydrochloric acid (or equivalent amount of another Acid) quenched. The product obtained by quenching is then separated, washed with alkali and then with water until neutral. After evaporation of the solvent, the residue is fractionated under reduced pressure to separate off the desired ester. If the product is water-soluble, quenching and work-up must be carried out in a non-aqueous medium.

The invention is illustrated by the following examples.

example 1

A reaction vessel, as described above, is charged with 420 g (2.0 mol) of phosphoric acid phenyl ester dichloride in 500 g of ether. With the agitator running, a solution of 645.4 g (4.0 mol) of n-butyl magnesium bromide is slowly added dropwise over a period of one hour. An exothermic reaction is observed and the reaction mixture is cooled to room temperature. The reaction mixture is then acidified with 10 ° / ₀ aqueous sulfuric acid and separated the forming ether layer. The ether layer is then subsequently and finally washed with 10 ° / ₀ aqueous sulfuric acid at 10 ° / _o aqueous sodium hydroxide solution repeatedly with water until a neutral reaction of the washing waters. After evaporation of the ether, the residue is fractionated under reduced pressure and 306 g of phenyl di-n-butylphosphinate are obtained in a yield of approximately 60 ⁿ / ₀ . The compound had a solution point of -62.2 ° C, a boiling point of 57.6 ° C / 0.4 torr.

The repetition of the same procedure with 467.6 g n-Butylmagne ^ siumchlorid and 422 g Phosphorsäurephenylesterdichlorid, each in ether yielded 443 g of di-n-butylphosphinsäurephenylester in a yield of about 87 ° / _0th

Example 2

In the same way as in Example 1, 289.7 g of n-hexyl magnesium chloride in ether are added dropwise to 211.0 g of phenyl ester dichloride in ether. The reaction product is cooled, washed and then fractionated and gives 275 g of phenyl din-hexylphosphinate in a yield of approximately 90 ° / ₀ . The compound had a solution point of -28.9 ° C and a boiling point of 68.5 / 0.2 Torr.

Example 3

ίο In the same way as in Example 1, 785.5 g n-Pentyl magnesium chloride in ether to form 633 g of phosphoric acid phenyl ester dichloride added dropwise in ether. The reaction product is cooled, washed and then fractionated to give 665 g Phenyl di-n-pentylphosphinate in one yield of about 89%. The compound had a solution point of 23.3 ° C and a boiling point of 72.2 ° C / 0.5 torr.

Example 4

211 g of phosphoric acid phenyl ester dichloride in 500 ml of ethyl ether are introduced into the reaction vessel described above. With stirring, 274 g of phenylmagnesium chloride, dissolved in tetrahydrofuran, are added dropwise over the course of 2 hours. After standing for 8 hours, the reaction mixture is _{quenched with 10 ° / 0} hydrochloric acid. An additional 1000 ml of ethyl ether are added to separate the reaction mixture into two layers. The aqueous layer is discarded and the ethereal layer is washed first with 10 ° / ₀ NaOH, then with water until neutral. The ether is then evaporated and the residue consisting of 95 ° / _o sodium recrystallized ethanol. Diphenylphosphinic acid phenyl ester with a melting point of 134 to 137 ° C. is obtained.

Example 5

211 g of phosphoric acid phenyl ester dichloride and 300 ml of a ^{solvent consisting essentially of η-hexane with a boiling range of 60 to 68 °} C. are introduced into the reaction vessel described above. 128 g of n-butyllithium are dissolved in 428 g of n-heptane with stirring and added dropwise at room temperature over a period of 2 hours. The reaction mass is then washed, dried and fractionally distilled. The product obtained shows a specific gravity _n ² j = 1.4918, compared to the specific gravity of pure phenyl di-n-butylphosphinate, n ² S = 1.4983.

The following phosphinic acid esters can be prepared in the same way:

G rignard reagent Halide product Solution
Point boiling point ⁰ C ° C / Torr neo-pentyl magnesium chloride Phosphoric acid phenyl Dineopentylphosphine -45.6 67 / 0.8 ester dichloride acid phenyl ester n-propyl magnesium chloride the same Di-n-propylphosphine -65.0 63 to 64.2 / 2.0 acid phenyl ester sec-butyl magnesium chloride the same Di-sec-butylphosphine -42.80 50.5 / 0.1 acid phenyl ester n-butyl magnesium chloride Phosphoric acid-p-meth- Di-n-butylphosphinic acid - 73.4 / 0.3 oxyphenyl ester dichloride p-methoxyphenyl ester

Example 6

227 g (~ 1 mol) of thiophosphoric acid-s-phenyl ester dichloride and 500 g of ethyl ether were introduced into a reaction vessel. To this, 233.8 g (~ 2 mol) of n-butyl magnesium chloride in a 3 molar solution in ethyl ether were added dropwise over the course of 2 hours. The reaction was allowed to complete at room temperature with stirring over an additional hour. The reaction mass was then quenched with 800 ml of 10 ° / _o hydrochloric acid, discarded the aqueous layer and the organic layer ml HCl, water, washed twice with aqueous 10 ° / _o sodium hydroxide solution and water were successively until the wash water to neutrality with 500 ( approximately four times). 175 g of di-butylthiophosphinsäure-s-phenyl ester were obtained, which corresponds to a 65 ° / _o solution of the theoretical yield. The compound has a solution point of -40 ° C and a boiling point of 53.5 ° C / 0.25 Torr, ao

Example 7

227 g (~ 1 mol) of thiophosphoric acid - o - phenyl ester dichloride and 500 g of ethyl ether were placed in a reaction vessel. To this, 233.8 g (~ 2 mol) of n-butyl magnesium chloride in the form of a 3 molar solution in ethyl ether were added dropwise over the course of 2 hours. The reaction was allowed to complete at room temperature with stirring over an additional hour. The reaction mass was then quenched with 800 ml of 10 ° / ₀ hydrochloric acid, discarded the aqueous layer and the organic layer washed successively with 500 ml of 2 ° / _o HCl, water, twice with aqueous 10 ° / ₀ sodium hydroxide solution and finally with water washed until the wash waters were neutral (approximately four times). 159 g Di-n-butylthiophosphinsäureo-phenyl ester were obtained, which corresponds to a 59 ° / _o solution of the theoretical yield.

Example 8

243.1 g (~ 1 mol) of dithiophosphoric acid s-phenyl ester dichloride and 500 g of ethyl ether were placed in a reaction vessel. To this, 233.8 g (~ 2 mol) of n-butyl magnesium chloride in the form of a 3 molar solution in ethyl ether were added dropwise over the course of 2 hours. The reaction was allowed to complete over an additional hour at room temperature with stirring. The reaction mass was then quenched with 800 ml of 10 ° / ₀ hydrochloric acid, discarded the aqueous layer and the organic layer washed successively with 500 ml portions of 2 ° / ₀ HCl, water, twice with aqueous 10 ° / ₀ sodium hydroxide solution and finally with water washed until the wash waters were neutral (approximately four times). 178 g Di-n-butyldithiophosphinsäure-s-phenyl ester were obtained, which approximately corresponds to a theoretical yield of 62 ° / _0th

Claims (1)

Claim: Process for the preparation of phosphinic acid esters of the general formula R ¹ Z - P (R ² ) ₂ by reacting a phosphoric acid ester chloride of the general formula (R ¹ Z) _7n PCl _n with an organometallic compound of the general formula R ² MX (II) where in the formulas R ^{1 is} a phenyl, alkyl, alkoxyphenyl, alkylphenyl or naphthyl radical with in each case 1 to 12 carbon atoms in the alkyl or alkoxy radical, Y and Z are oxygen or sulfur, m and η are 1 or 2, where m and η together is 3, R ^{2 is} an aryl, alkyl or alkaryl radical each having 1 to 12 carbon atoms in the alkyl radical, M is magnesium, aluminum, sodium or lithium and X is bromine or chlorine, characterized in that under Stirring in the solution of the phosphoric ester chloride I, a solution of the organometallic compound II is added dropwise in about twice the molar amount per mole of I at reflux temperature, the reaction mixture is allowed to cool, acidified, then washed until neutral and the product is isolated in the usual way. Considered publications:
Reports of the German Chemical Society, (1915), pp. 316 to 318.