CH414624A - Process for the preparation of acylation products of phosphorous acid - Google Patents

Description

  

  
 



  Process for the preparation of acylation products of phosphorous acid
The invention relates to a process for the preparation of acylation products of phosphorous acid with at least 2 phosphorus atoms in the molecule, characterized in that phosphorus trichloride with saturated or unsaturated polycarboxylic acids, unsaturated monocarboxylic acids or saturated monocarboxylic acids with at least 7 carbon atoms in the molecule, or phosphorous acid with halides or Anhydrides of the carboxylic acids mentioned.



   The reaction is expediently carried out at an elevated temperature, preferably between 50 and 2000.degree. It has surprisingly been found that in the reaction only 1 mole of acylating agent always reacts with 2 moles of H3PO3 when the acylating agents are derived from monocarboxylic acids. If the acylating agents are derivatives of dicarboxylic acids, 1 mole of acylating agent reacts with 4 moles of H3PO3. However, it has been found to be expedient to generally work with an excess of acylating agents.



  This can be up to four times the amount theoretically required by the above reaction mechanism. You can of course work with even larger quantities, but this has practically no advantages.



   Suitable acylating agents are halides or anhydrides, especially of dicarboxylic acids, for example malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid or also acrylic acid, fumaric or maleic acid. But it can z. B. also halides of aromatic carboxylic acids, especially benzoic acid or halides or anhydrides z. B. of aliphatic monocarboxylic acids with at least 8 carbon atoms, that is, of compounds such as caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid.



   Finally, it is also within the scope of the invention, instead of phosphorous acid and acid halides or anhydrides, to start from phosphorus trichloride and the acid corresponding as acylating agent, provided this reacts readily with the phosphorus trichloride to form phosphorous acid and acid chloride, which is generally the case. The reaction time, which, as already stated above, is expediently carried out at elevated temperature, depends on the one hand on the temperature used and on the other hand on the reactivity of the acylating agent and is generally from 30 minutes to 24 hours.



   The reaction is conveniently carried out with stirring. The application of pressure is not required. Since the use of excess acylating agents is advantageous in order to achieve a good yield, the excess acylating agent is separated off after the reaction has ended. This can generally be done by distillation, preferably under reduced pressure. The reaction products are generally soluble in water or in alcohol and, if desired, can be converted into the corresponding alkali metal salts.



  This can be done, for example, by neutralization with alkali such as NaOH, KOH, Na2CO3 or ammonia in the presence of water or with alcoholic alkali solutions.



   The constitution of the phosphonic acids which can be prepared by the process according to the invention is still completely clear. It is clear, however, that these are always compounds that contain at least 2 phosphorus atoms in the molecule. In any case, if certain reaction conditions are observed, products of the same overall composition and the same properties can be produced in a reproducible manner.



   The new phosphorus compounds, especially if they contain a longer carbon residue, have surface-active properties and can be used accordingly. The others
Products are particularly suitable as anti-corrosion agents or additives to anti-corrosion agents.



   example 1
0.2 mol of phosphorous acid and 0.3 mol of lauric anhydride were stirred at 1400 ° C. for 24 hours.



  Volatile products were then distilled off at a temperature of 1400 ° C. and a pressure of 1 mm Hg. The residue was dissolved in ethyl alcohol and neutralized with alcoholic sodium hydroxide solution, the salt separating out firmly.



   The yield was 85% based on the phosphorus used. Analysis values C = 35.87%, P =
14.23%.



   Example 2
2 mol of phosphorous acid were mixed with 2.6 mol of maleic anhydride and heated to 1400 ° C. for 11 hours with stirring. After working up as described in Example 1, the yield of the end product was 42%, based on the phosphorus used. The proportion of carbon was 22.6% and of phosphorus 8.81%.



   Example 3
A mixture of 1 mole of phosphorous acid and
1.5 mol of caprylic acid chloride was slowly heated to 1400 ° C. with stirring and left at this temperature for 5 hours, with strong evolution of HCl. All volatile constituents were then distilled off at a pressure of 2 mm Hg and a temperature of up to 1800 C. The residue was dissolved in alcohol and neutralized with alcoholic sodium hydroxide solution and the salt which precipitated out was filtered off with suction and dried. The yield was 82.5%, based on the phosphorus used. Analysis values: C = 32.25%, P = 17.09%.



   Example 4
6 mol of caprylic acid were added ver with 2 mol of PC13 and stirred at 500 ° C. for 11/2 hours. The temperature was then increased to 1400 ° C. and left at 1400 ° C. for 5 hours. Volatile constituents were then distilled off at 2 mm Hg pressure and a temperature of up to 1800 C. The residue was dissolved in alcohol, neutralized with alcoholic sodium hydroxide solution and the salt which precipitated was filtered off with suction and dried. The yield was 78%, based on the phosphorus used. Analysis values: C = 29.40,
P = 17.07X.



   Example5
A mixture of 1 mole of phosphorous acid and
1.5 mol of stearic acid chloride was slowly heated to 1600 ° C. with stirring and left at this temperature for 24 hours. Then were at 2 mm Hg pressure and a temperature of about
1800 C the volatile constituents distilled off. The residue was dissolved in alcohol and neutralized with alcoholic sodium hydroxide solution.



   The yield of the end product was 60%, based on the phosphorus used.



   Example 6
0.52 mol of glutaric acid dichloride and 2 mol of phosphorous acid were stirred at 14,000 for 24 hours.



  The reaction product was then dissolved in water and adjusted to pH 11 with sodium hydroxide solution.



  The salt was precipitated with alcohol and the syrup which had precipitated was converted into solid form by adding methanol, filtered off with suction and dried. The yield was 78%, based on the phosphorus analysis values used: 0 = 11.52%, P = 14.82%.



   Example 7
The table below shows the preparation of a number of other acylation products of phosphorous acid, specifying the molar ratios of the starting products, the heating time, the temperature and the yield (based on the phosphorus used) and the analytical composition of the products. The reaction products with lauric acid, acrylic acid and benzoyl chloride were worked up as in Example 3, the other reaction products as described in Example 6, worked up.



     ... molar ratio heating time temperature yield C or P acid derivative HsPOs: acid derivative hours bC% proportion in the end product lauric acid chloride 1: 1.4 2 150 88 38.51 13.11 malonic acid dichloride 1: 1 2 130 81 12.35 18.06 Adipic acid chloride 4: 1 20 140 59.5 9.81 16.64 Acrylic acid chloride 1: 2 4 100 60 26.45 13.03 Fumaric acid dichloride 2: 1 5 120 70 11.52 14.64 Benzoyl chloride 1: 1.5 6 130 49 16.68 14.71

 

Claims (1)

PATENT CLAIM Process for the preparation of acylation products of phosphorous acid with at least 2 phosphorus atoms in the molecule, characterized in that phosphorus trichloride is reacted with saturated or unsaturated polycarboxylic acids, unsaturated monocarboxylic acids or saturated monocarboxylic acids with at least 7 carbon atoms in the molecule or phosphorous acid with halides or anhydrides of the carboxylic acids mentioned. SUBCLAIMS 1. The method according to claim, characterized in that halides or anhydrides of dicarboxylic acids are used as acylating agents. 2. The method according to claim, characterized in that halides or anhydrides of aromatic carboxylic acids are used as acylating agents. 3. The method according to claim, characterized in that halides or anhydrides of aliphatic monocarboxylic acids having at least 8 carbon atoms are used as acylating agents. 4. The method according to claim and dependent claims 1 to 3, characterized in that the reaction is carried out at temperatures between 50 and 2000C. 5; Process according to dependent claim 1, characterized in that 0.25 to 1 mole of acylating agent is used per mole of H3PO3. 6. The method according to dependent claims 2 and 3, characterized in that 1 to 2 moles of acylating agent are used per mole of H3PO8.