SU258306A1 - METHOD OF OBTAINING BIS-p-BROMETHYLPHOSPHINE ACID OR ITS DERIVATIVES - Google Patents

Description

The invention relates to the preparation of phosphinic acid and its derivatives.

A known method for producing trivalent phosphorus acid esters by reacting three-halide phosphorus with ethylene oxide, and a method for producing pyvalent phosphorus acid esters from trivalent phosphorus acid esters using Arbuz's rearrangement.

A method is proposed for the preparation of bis-p-bromoethylphosphinic acid or its derivatives with the general formula (BrHCH2SP2) 2P (0) X, where X is OH, C1, substituted or unsubstituted alkyl.

The method is that p-bromo ethyl ebl bromophosphine is reacted with ethylene oxide. The p-bromoethylphosphinic acid di-bromoethyl ester thus obtained is isomerized by boiling to p-bromoethyl bis-p-bromo-ethylphosphinic acid ester, which is then converted by known methods IB trans-bromo-ethylphosphinic acid or its derivatives. For example, when passing hydrogen ether and hydrogen bromide through this ester, bis-bromoethylphosphinic acid is obtained, when it is treated with phosphorus chloride, bis-p-bromoethylphosphinic acid chloride, and the corresponding ester is obtained from the latter by the addition of alcohol.

New compounds are heat resistant and are of interest as flame retardant additives. In addition, they can be used as starting materials in the synthesis of monomers for the production of organophosphorus polymers, etc.

Example 1. To a solution of 172 g of p-bromo ethyldibromophosphine in 500 cm 3 of toluene, gaseous ethylene oxide is passed under stirring, maintaining the temperature at 5 ° C until the end of heating. The solution is transferred and boiled under reflux for 1 hour, and then the solvent is distilled off, finally under vacuum. The residue gives bis-p-bromoethylphosphinic acid p-bromoethyl ester, which gradually turns into a colorless crystalline mass. The yield of the product is 207 g (94%), it is suitable for many purposes and can be cleaned of a small amount of polycondensation products by film distillation. The yield of the purified substance thus 169 g (99%), so pl. 35-36 ° C.

C, 18.66;

P 8.13; Br 62.50;

%:

Found 5 N 3.20.

CaH12VgzO2R.

P 8.00; Br 61.96; C, 18.62;

Calculated,%: H 3.12. ethylene oxide is passed. Upon termination of the heat, the solvent and excess ethylene oxide are removed in vacuo. In the residue, 119 g (100%) of p-bromoethylphosphinic acid di- | 3-bromoethyl ester is obtained, which is a colorless mobile liquid with df 1.8943, n2 ° 1.5535, and MRo is found. 65.27, cal. 65.33. Found,%: P 8.20; W 61,54. CoHiaBrsOsP. Calculated,%; P 8.00; Br 61.96. When heated to 110 ° C, a backward reaction starts, leading mainly to oligomeric products. Isomerization in a toluene solution is carried out similarly to that described in Example 1. p-Bromoethylphosphinic acid di-p-bromoethyl ester attaches sulfur, and p-Bromo-ethylphosphinic-nyl ester readily forms with chloral. Found,%: P 7.96; C, 18.80; H 2.55. SvnaVgaSYOZR. Calculated,%: R 7.94; C, 18.48; H 2.07. Example 3. A double molar excess of hydrogen bromide is passed through 38.6 g of p-bromoethyl ester of bis-p-bromoethylphosphonic acid with stirring and heating to 100 ° C, the dibromoethane is distilled off and the crystalline residue is recrystallized from benzene to give 23.4 g ( 83.5%) bis-p-bromoethylphosphinic acid (colorless plates with mp 85-86 ° C). Found,%: P 11.08; W 56.30; C 17.00; H 3.20; 5KV. weight 282.6 g. CiHeBrsOaP. Calculated,%: R 11.06; Br 57.09; C 17.52; H 3.24; eq. weight 279.9 g. Example 4. To a suspension of 27.99 g of bis-p-bromoethylphosphinic acid in 150 ml of benzene, a solution of 20.82 g of phosphorus chloride in 150 ml of benzene is added dropwise with stirring, maintaining the temperature of 20-25 ° C by cooling. Then the solvent and phosphorus oxychloride are distilled off in vacuum. This gives 27.1 g (91%) of bis-bromoethylphosphinic acid chloride (colorless needles with mp 73-75 ° C from benzene). Found,%: P 10.10; C 15.98; H 2.55. CiHsBrsClOP. H 2.70. : R 10.38; C 16.10; Calculated is g p-bromK solution of 38.68 Example 5. ETHYL Bis-p-bromoethylphosphinic acid ester in 100 ml of benzene is added dropwise with stirring a solution of 20.82 g of phosphorus chloride in 150 ml of benzene, keeping the temperature at 20-25 ° C with cooling. Next, the solvent, phosphorus oxychloride and 1,2-chlorobromoethane are otgol in vacuum. This gives 27.91 g (92%) of bis-pbro-methyl ethylphosphinic acid chloride (colorless acicular crystals with mp 73-75 ° C from benzene). Example 6. To a solution of 29.83 g of bis-p-bromoethylphosphinic acid chloride in 200 ml of benzene, a mixture of 4.6 g of ethanol with 10.1 g of triethylamine is added dropwise while stirring, while keeping the temperature at 20-25 ° C by cooling. The hydrochloric triethylamine is then filtered off and the solvent is distilled off in vacuo from the filtrate. Obtain 29.4 g (96%) of ethyl ester of bis-p-bromoethylphosphonic acid (colorless needles with mp. 76-77 ° C from the ether). Found,%: P 9.98; C 23.11; H 4.16; Br 51.50. SbNiVgggOGR. Calculated,%: R 10.02; C 23.32; H 4.58; Br 51.40. Example 7. A mixture of 10.2 g of bis-p-bromoethylphosphinic acid and 30 ml of triethylorthoformate is heated under stirring to 120 ° C for 2 hours, then the excess of triethyl orthoformate is distilled off in vacuo to give 10.3 g (90.4%) of ethyl ether Bis-p-bromoethylphosphinic acid with properties identical to those described in Example 6. Subject of the invention. A method for the preparation of bis-p-bromoethylphosphinic acid or its derivatives of the general formula (Br 2 CH 2 CH 2) 2 P (0) X, where X is OH, C 1, substituted or unsubstituted alkyl, characterized in that p-bromo ethyldibromophosphine is subjected to interaction with oxides Strongly ethylene followed by refluxing the resulting di-p-p-bromoethyl ether brometilfosfinistoy noluchenny acid and wherein the p-bromoethyl ether of bis-p-brometilfosfiovoy acid was converted to the bis-p-brometilfosfinovuyu acid or its derivatives by known methods.