DE1148235B - Process for the preparation of acylation products of phosphorous acid with at least 2 phosphorus atoms in the molecule - Google Patents

Description

GERMAN

PATENT OFFICE

H 43035 IVb / 12 ο

REGISTRATION DATE: JULY 3, 1961

NOTICE THE REGISTRATION AND ISSUE OF EDITORIAL:

May 9, 1963

Various processes are available for the production of acetylation products of phosphorous acid known.

So you can, for example, acetyl chloride and phosphorous acid, if appropriate in the presence of React acetic anhydride.

Another way of working that is often used in practice is to use acetyl chloride instead of acetyl chloride and phosphorous acid to start from such components that form these substances react, d. That is, one can also start from PCI3 and anhydrous acetic acid, with these components used in a ratio of 1: 3 for stoichiometric reasons.

It has now been found that it is possible - without affecting the yield of the acylation products to be prepared of phosphorous acid with at least 2 phosphorus atoms in the molecule is practically reduced - part of the previously used Replace acetic acid with water. In the process according to the invention, 1 mol is used Phosphorus trichloride with a total of at least 2.5 mol, preferably 3 mol of carboxylic acid and water, where the water content can be up to 1.6 mol, at temperatures below 80 ° C, preferably 50 ° C, and then heated the reaction mixture for a while - if necessary under Stirring - to temperatures between 80 and 200 ° C, preferably 100 and 160 ° C. During execution the reaction is expediently phosphorus trichloride while stirring a mixture of acetic acid and water added slowly. The reaction mixture is optionally used refrigerated to avoid overheating. However, you can also proceed in the opposite way. Finally, you can mix phosphorus trichloride with the carboxylic acid and then add water, or the other way around. However, the procedure given first is generally preferable.

As has also been found, the reaction can also be carried out with others in addition to acetic acid Carboxylic acids, especially propionic acid, butyric acid, caproic, caprylic, capric acid, or acids with an even longer carbon residue such as lauric acid. Continue to come too polybasic carboxylic acids, especially dicarboxylic acids, or aromatic carboxylic acids, such as Benzoic acid. In this way not only acetylation products are obtained, but also acylation products of phosphorous acid.

After the reaction is complete, the reaction process for the production of

Acylation products of phosphorous

Acid with at least 2 phosphorus atoms

in the molecule

Applicant:

Henkel & Cie. GmbH.,
Düsseldorf-Holthausen, Henkelstr. 67

Dr. Bruno Blaser, Düsseldorf-Urdenbach,

Dr. Hans-Günther Germscheid,

Hösel near Düsseldorf,
and Dr. Karl-Heinz Worms, Düsseldorf,
have been named as inventors

^a 5 product worked up by separating off excess acylating agents. This can generally be done by distillation, preferably under reduced pressure. In the presence of acetic acid, partial distillation of acetyl chloride already takes place during the previous heating of the reaction mixture to a higher temperature. The reaction product obtained can either be used directly or, if appropriate, after purification, such as, for example, recrystallization or other known processes. Treatment with water under certain conditions, namely at temperatures above 60 ° C., has proven to be particularly useful. However, this cleaning method is not the subject of the present patent application.

It is often useful to convert the acids produced into the corresponding alkali metal salts, which for example by neutralization with alkaline solutions in the presence of water or with alcoholic solutions Alkali solutions can be done.

The acylation products or their alkali salts can be used to prevent calcite precipitation in the Water softening or also to stabilize per compounds are used.

The constitution of the acylation products which can be prepared by the process according to the invention the phosphorous acid is partly not yet

309 579/292

completely clarified. According to previous investigations, it is always in the cases where monocarboxylic acids were converted to compounds of the general formula

ORO

HO

OH

OH OH OH

where R denotes an alkyl radical which has 1 C atom less than that used for the reaction Has carboxylic acid. However, it is certain in all cases that it is always a matter of connections which contain at least 2 phosphorus atoms in the molecule, and it is possible if certain Reaction conditions Products of the same gross composition and the same properties in reproducible way to produce.

The partial use of water instead of the acylating agent according to the invention Otherwise, the process leads to the same products as when using the acylating agent without Addition of water can be obtained.

example 1

1.8 mol of acetic acid and 1.2 moles of water were slowly added with stirring to 1 mole of PCl 3 and the temperature slowly raised to 12O ⁰ C within 2 hours and left for a further hour at this temperature. Steam was then blown into the resulting syrup at 140 ^° C. until the distillate was practically acid-free. After cooling, a crystalline product is obtained. The acid could be recrystallized from a little water.

The yield was 103 g or 92% (based on the phosphorus used).

Example 2

4.0

245 kg of PCI3 were added to a mixture of 190 kg of 90% acetic acid and 26 g of water (molar ratio CH ₃ CO ₂ H: H2O = 1.6: 1.4), with cooling occurring after initial heating to 40 ° C. Subsequently, while stirring and distilling off some acetyl chloride, the temperature of the reaction mixture was increased to 120 ^° C. and kept at this temperature for 1 hour. 150 liters of water were added to the viscous reaction mixture and steam was blown in at 130.degree. The acid, which was still pumpable, was neutralized in a mixing nozzle with 50% sodium hydroxide solution, the reaction product solidifying and being ground on cooling. A 1% solution of this product had a pn value of approximately 7.

The yield was 298 kg or 94% (based on the phosphorus used).

Example 3

1.8 mol of propionic acid are mixed with 1.2 mol of water, 1 mol of PCI3 was added dropwise with water cooling and stirring. With further stirring, the temperature was finally increased up to 13O ⁰ C and held for 1 hour at this temperature. Steam was blown through the viscous product for 1 hour. The concentrated aqueous solution of the acid was then adjusted to pH 7 with 40% strength sodium hydroxide solution and the reaction product was crystallized by adding a little methanol.

The yield was 155 g or 78.5% (based on the phosphorus used).

Example 4

3 moles of caproic acid were mixed with 3 moles of water. 2 mol PCI3 were added dropwise with stirring and water cooling. After the exothermic reaction had subsided, the mixture was ^{heated to 140 °} C. and ^{stirred at 140 °} C. for 3 hours. The reaction product was then treated with steam as in Example 3. The aqueous acid solution was adjusted to pH 7 with 40% sodium hydroxide solution, and the sodium salt crystallized out in beautiful crystals by adding a little methanol.

The yield was 240 g or 66.8% (based on the phosphorus used).

Example 5

2 moles of PCI3 were added dropwise to a mixture of 3 moles of lauric acid and 3 moles of water over the course of half an hour. Then the reaction mixture under stirring was first heated for 1 hour at 70 to 8O ⁰ C and then 3 hours at 140 ° C. The volatile constituents were then distilled off in vacuo (3 mm Hg, 120 ° C.). The residue was dissolved in ethanol and the sodium salt was precipitated with alcoholic NaOH.

The yield was 80.5% (based on the phosphorus used) or 369 g.

Example 6

1.5 mol of benzoic acid were mixed with 1.5 mol of water and 1 mol of PCI3 was added dropwise to this mixture. The mixture was then heated to 130 ° C. for 6 hours and then the reaction product was distilled with steam until the distillate was acid free. The residue was neutralized with 40% NaOH to pH 7 and by adding alcohol brought to crystallization.

The yield was 70% (based on the phosphorus used) or 118 g.

Example 7

1.2 mol of PCl ₃ were added dropwise to 0.5 mole of 8O ⁰ C heated adipic acid and the mixture stirred for 1 hour at this temperature, said two layers formed. Then 2.5 mol of water were added while cooling with ice and sodium chloride. Then the reaction mixture with stirring was heated to 16O ⁰ C for 8 hours. The reaction product was dissolved in water, 20% strength sodium hydroxide solution was added until a pH of 7 was reached, and the end product was precipitated with methanol.

The yield was 57% (based on phosphorus used) or 117 g.

Claims (1)

PATENT CLAIMS: 1. A process for the preparation of acylation products of phosphorous acid with at least 2 phosphorus atoms in the molecule by reacting phosphorus trichloride with carboxylic acids, characterized in that per mole of phosphorus trichloride a total of at least 2.5 moles, 5 6 preferably 3 moles Caroonsäure and water, temperatures between 80 and 200 ⁰ C, preferably where the water content is up to 1.6 moles 100 and 160 ⁰ C, is further heated, can, at temperatures below 80 ⁰ C, before 2. The method according to claim 1, characterized preferably 50 ⁰ C, implemented and the reaction characterized that the starting components mixture then for a while at temperature 5 phosphorus trichloride is added last. © 309 579/292 4.63