DE1768132C - Process for the production of alpha beta olefinically unsaturated alkyl phosphonic acid esters - Google Patents

Description

Ί, / ί-olefinically unsaturated alkyl phosphonic acid esters are increasingly being added to the polymerization of numerous monomers. These phosphonals are used as polymerizing agents, chain firing agents and crosslinking agents are used in areas of application where there is a need for flame resistance of the polymers matters because these phosphonates give the polymers a certain amount Impart flame resistance without adversely affecting other desirable properties. With increasing New methods for the production of the Pho'phonate have become known. The best so far The method for the preparation of these compounds is that from US Patents 2,959,609 and 3,064,030 as well as the German Auslegeschrift 1 006 414 known dehydrohalogenation of a corresponding "" - haloalkylphosphonic acid ester using a stoichiometric amount of an alkali metal salt a lower fatty acid, preferably anhydrous sodium acetate. Applying this Dehydrohalogenating agent leads to yields of about 10 to about 90%. The byproducts Fatty acids cannot be regenerated.

Another known hydrohalogenating agent is the cheaper sodium carbonate. However, this means gives low yields of about 50%, requires higher reaction temperatures and is therefore ineffective and impractical.

The use of the preferred alkali metal salts especially sodium acetate, but it is considerably more expensive than the use of alkali metal carbonates, uiid despite the excellent speed of reaction they lose interest in these funds for reasons

The invention relates to a process for the preparation of ^ -olefinically unsaturated alkylphosphonic acid esters by reacting a _r ; -chlorine (bromine. Iodine) alkylphosphonic acid ester with a de-

hydrohalogenating agents at elevated temperature, characterized in that the dehydrohalogenating agent used is a mixture of (a) alkali metal carbonate " or alkali metal bicarbonate and (b) an organic acid, which is in 0.1 η solution at 25 C

has a pH of about 1 to about 6, in the molar ratio (a): (b) of about 25: 1 to about 2: 1 used, where the component (a) in stoichiometric amount, based on the, »'- haloalkylphosphonic acid ester, or in small excess and

component (b) is used in an amount of OX "to 0.2MoIMoI; -halogena \ ky \ phosphon <; acid ester will.

When using sodium carbonate 4 more catalytic! Amounts of acetic acid according to the invention

Instead of the known use of stoichiometric amounts of sodium acetate, production work is simplified, since less acetic acid (about 5 " of the amount obtained in the known process) has to be washed out of the crude product

at the same time the wastewater problem is made much easier, because the recovery of acetic acid from the wash water is for economic reasons is out of the question.

Preferred embodiments of the invention

use sodium carbonate or bicarbonate and acetic acid as an organic acid catalyst. Benzoic acid or a phenolic acid such as nitrophenol or chlorophenol and a molar ratio of (a): (b) from about 10: 1 to about 4: 1.

Acids which are indefinitely soluble in water can also be used, as can acids which only have a solubility of 0.1 g / 100 ml of water at the reaction temperatures. It can even Acids with even lower solubility can be used, but these are not preferred. Likewise the acid salt should be in the organic phase, i. H. in the haloalkyl-bis-haloalkylphosphonate in be soluble to about the same extent. The wish that the acids should be just as soluble in water like the salts, is based on the fact that these materials become contaminants towards the end of the reaction s and must be removed, preferably by washing with water, for which theirs Water solubility is beneficial.

It is true that any organic acids, regardless of the number of their carbon atoms, can be used as Catalysts are used, however, according to the procedure the use of such organic acids is preferred which have 1 to 12 carbon atoms own. This includes both monobasic and polybasic acids. They include connections, which acidic substituents, rvic carboxylic acid groups, phenolic hydroxyl groups, phosphinic acid groups, Phosphonic acid groups, phosphoric acid groups,

do contain sulfonic acid groups. Most preferred among these acidic catalysts are the organic carboxylic acids and phenolic acids. This preference is based on relatively low cost, easy availability, high solubility and reactivity of these acids. Examples of such organic acids are formic acid, Vinegar, propion, butter, pentane carbon. Hexanecarboxylic, pclargonic, undccanic, methacrylic acid,

rveloaliphatic carboxylic acids, such as hexahydrobenioic acid, bifunctional acids such as oxalic acid succinic acid. Maleic acid. Phthalic acid. Pyromelitic uipic acid. Hexanedicarboxylic acid. die'aromatic Carboxylic acids such as benzoic, aminobenzoic. Nitro-> beiv.de-. Chlorobenzoic acid and toluic acid. the phenol see acids, like nitrophei.o'l. Chlorophenol PIunol. Salicylic acid, ("resol. Sulfonic acids, such as toluene-sulfonic acid. Octanesulfonic acid. and the phosphorous organic acids, such as the phosphinic acids Phosphonic acids and phosphoric acids, e.g. B. Phenylp!; V -sphonic acid. Phenylphosphinic acid.

As mentioned earlier, certain organic acids, such as the phenols and carboxylic acids, are preferred. Γ-in front of these are those with low or relative iv; -. i; igen molecular weight is most appropriate. /. :;. Benzoin. Hexanydrobenzoic. Heptane carbon. 1 ■ :. ^ lon-. Chloroacetic acid. Acetic acid. Phenol. Pentachlorpi Uli. Dinitrophenol. Furthermore, amine-free S - .. rn preferred because acids contain amine groups ni-.v '. ·. igerc yields.

μ ground the acids according to the invention with the Ai ''. uimetallcarbonat according to the invention ange-WL-iii!, · !. then alkali metal salts of these steels are formed.

/ liter of stoichiometric amount of alkali metal carbonate, limited to ₍ ; -Halog nalkylphosplionsäureester, versii.-ii! one 0.5 mol sodium carbonate.

! las ammonium is generally considered to be an aquatic \: «. Lc: it apart from the alkali metal ions and falls thus under the term used here »alkali

IXis method according to the invention can be based on compounds the formula

R "C

- C

C ₁₁ H _{211 + 1}

O OR

i'i /
P.

'\
OR '

35

in which η and »1 are integers from 0 to 6, preferably 0 to 4, are used. X ^ is chlorine, bromine or iodine, R and R 'contain hydrocarbon groups with 1 to 18 carbon atoms. R "is a hydrocarbon group with 0 to 18 carbon atoms.

Hydrocarbon radicals are understood to mean aliphatic or aromatic groups, which are only contain such sub-mituations as the reactivity or do not change the character of the hydrocarbon groups. Such inert substitutions are z. B. chlorine, fluorine, nitro. Flydroxy-. Mercapto, Sulfone, ethow, methoxy, nitrile, thioether, ether, F.ster-, KcIo-. Sulfone groups.

Examples of aliphatic groups represented by R. R 'and R "are symbolized, are alkyl radicals, such as methyl, ethyl, propyl, butyl ·. Pentyl, llexyl-. Nonyl. Pentenyl-, llexenyl-. Cycloalkyl-. ('yelopropyl-, cyclobutyl-. cyelopentyl-, cyclohexyl- (.0 Cyclohexenyl radical. and examples of aromatic groups are the phenyl. Benzyl. Phcnäthyl-, ToIyI-, Naphthyl resin.

Of particular interest is the production of bis - (, i- < chloroethyl) vinyl phosphonate. hereinafter referred to as (15 for short. CAVP.

The dehydrohalogenation takes place at a temperature between about ¹ ° C and about 130 ° C., especially between about 115 and about 120 ° C. accomplished. The reaction can, however, be carried out at any temperature between room temperature and about 225 ° C, but low temperatures lower the reaction rate and high temperatures increase costs.

The dehydrohalogenation can be carried out in the presence of an inert solvent, although the presence of such a solvent is neither necessary nor particularly expedient is. Examples of inert solvents are acetone, methyl ethyl ketone, dimethyl ether, diethyl ether, acetonitrile, Methanol, benzene. Toluene, chlorobenzene, tetrahydrofuran, carbon tetrachloride, dimethyl sulfoxide, Diethylene glycol dimethyl ether, dimethyl sulfide, nitroalhan. Nitrobenzene. Carbon bisulfide. Glycols. Dioxane. Cyclohexane. Heptane. Petroleum ether.

Atmospheric pressure can be used in the dehydrohalogenation, although if desired can also be used under niospheric pressure and above atmospheric pressure. In the example Table 1 lists sodium bicarbonate and acetic acid used in an experiment at reduced pressure. On another attempt using the pressure of sodium carbonate and acetic acid was 1 atm. and the yield was in both Cases about 90 ". ·.

The dehydrohalogenation system used in accordance with the invention can also consist of a small amount of an alkali metal salt of an organic acid Place of the free acid. However, it is preferred to use the free acidic catalyst use, which is added to a certain amount of an alkali metal carbonate and thereby the Forms acid salt in situ. The component (a) of the dehydrohalogenating agent becomes stoichiometric Amount, if desired in a small excess, applied. In this case the excess is about 2 to 10 percent by weight, based on the chloroethylphosphonate.

Mixtures of such acids can also be used as acidic catalysts, as can mixtures the carbonates.

The materials used can be analytically re'ner. technically pure and raw quality.

Although it is not advisable to use aqueous solvents or water-based solvents, however, the reaction conditions need not be anhydrous. That in the reactants or Water contained in dehydrohalogenation agents does not adversely affect the yield if it does not is present in excessive quantities. Amounts of water from about 1 to about 20%. based on the Weight of the materials, have no adverse effect, however, this water must be removed in the end will. It is therefore advisable to adjust the amount of water to keep at a minimahvcrt.

A serious problem due to foaming can arise during the implementation of the reaction of the present invention, and for this reason it is desirable to add one of the known antifoam agents. Positive pressures can also be used to prevent foaming : .u . Since the foam is created by the CO released during the reaction, its formation can be completely avoided, but can be controlled by the methods mentioned above.

If a l.ösunusmillcl is used, i1.> ^V

Product can be purified and recovered by filtration and distillation. Will the implementation in In the absence of a solvent, the product can be recovered directly and washed be cleaned with water. Washing is the easiest way to clean the product however, results in little product loss, generally less than about 2%.

In the following examples and throughout the description, all parts and percentages relate on weight, unless otherwise stated.

example 1

Manufacture of bis (2-chloroethyl vinyl phosphonate (CAVP)

120 ^c C

CH, = CHP (OCh ₂ CH ₂ CD ₂

CICH ₁ CH ₁ P (OCh ₁ CH ₁ CI), Several reactions were performed using various dehydrohalogenating agents and systems. The temperature was kept at 120 ° C. in each case. The reaction time

ίο is given in Table 1. Equivalent amounts of Chlorethyl bis-I-chToräthylphosphonat, in the following referred to as CAP for short, and equivalent amounts of dehydrohalogenation catalyst have been added to the Given reaction vessel and this heated to 120 "C

and there during the implementation period The product mixture was ■ alysed. The venu-p deten means and systems, the refraction conditions, and the percentage yield are in the TabclL-! reproduced.

table

comparison 1. comparison Ί comparison 3. comparison 4th comparison 5. invention 6th invention 7th comparison 8th. comparison 9. comparison 10. comparison 11th

Dehydrohalogenating agents

Calcium oxide (30 g)

sodium
(55 g)

sodium
(85 g)

sodium
(85 g) + 5 mole percent water (1 g)

sodium
(55 g) *) 5 mol percent water (1 g)

sodium
(35 g) *) 5 mol percent acetic acid
(3 g)

sodium
(55 g) *) 5 mole percent acetic acid
(3 g)

5 mole percent acetic acid (3 g)

5 mole percent

Sodium acetate (4.5 g)

Acetic acid (60g)

Sodium acetate (82 g)

temperature

120 120

120 120

120 120

120

120 120 1.10

120 response

length of time
Sid.

total quantity

itochiom.
stoichiom.

stoichiom.
stoichiom.

stoichiom.
stoichiom.

stoichiom.

5% stoichiom.
5% stoichiom.
stoichiom.
stoichiom.

pressure

Atmosphere Atmosphere

Atmosphere 30 mm Hg

30 mm Hg 30 mm Hg

Atmosphere

Atmosphere Atmosphere

Approximate yield

20% traces

sense

40%

Traces 90%

90%

Ester the

Acetic acid 92%

Theoretically estimated on the basis of examples I to 7 and lü to

The yields in Table 1 were obtained by gas chromatographic analysis or by means of the Distillate calculated.

Example 2

The CAP used had the following characteristics determined by distillation:

76% CAP (KP _n ^ 154 to 164 C),
17% residue ',

7% low boiling fraction, less than
P (OCH ₂ CH ₂ CI) ,.

I% In a 1-1 three-necked flask made of hard-to-melt Glass moving with a paddle stirrer (600 rpm). Nitrogen inlet and outlet tube and thermometer

bo was equipped. 287.8 g of crude CA P from 76% Content (0.812MoI CAP on the basis of 100%) given. 6.4 g (0.1 mol) of acetic acid were added (10 mole percent of crude CAP) and 56.7 grams of anhydrous sodium carbonate (0.535 moles). This is the thcc retic amount for 287.8 g of 100% CAP.

The mixture was kept under a nitrogen stream IMD stirred while it was heated for 30 to 45 minutes at 120 Q. There was strong CO ₂ em-

Winding observed when the temperature was 95 to 100 C. had achieved: this can lead to excessive foaming if the heating rate is in this critical Phase is not carefully regulated. The reaction was slightly exothermic at this stage. The The mixture was held at 120 ° C. for 1 to 1.5 hours.

It was then cooled to 20-25 ° C and 290 ml of water was added. The mixture was stirred for 15 to 20 minutes to dissolve solid sodium chloride formed during the reaction. The reaction mixture was then placed in a separatory funnel and allowed to stand for ₁ to 1 hour to separate the two layers.

The lower, milky product layer was drained into a flask; she weighed 242 g. The water layer was extracted with 50 ml of benzene. The benzene (top layer) was used to remove the solvent evaporated. It contained 6.5 grams of organic material which was combined with the product layer. The product layer contained about 20 grams of water. This layer was mixed with 240 ml of water, which was mixed with 6 g Sodium bicarbonate had been brought to a pH of 7 to 8. extracted. The organic Layer was placed in a distillation flask. The water layer was then mixed with 50 ml of benzene extracted. The benzene layer contained 10 g of organic material. The lkn / .ol layer can be directly connected to the Product can be combined or evaporated separately, and the organic residue can be added to the product are given.

The product was tested under I to iOTorr at! 0Q C evaporated to remove the water. The remaining product weighed 214 g. This product was distilled at 0.2 to 0.5 mm Hg without a column. About 30 g of undistillable residue remained in the distillation flask.

Yield of CAVP: 1X3.8 g (0.78SMoI = 97% Yield).

Physical characteristics: Kp. ,,., 113 to 130 C.

η ■ = 1.4755.
Acidity: 0.4 mm 0.1 η NaC) H, 10 g.

Elementary analysis:

Found ... P 13.0. Cl 30.3%. Bromine number 685:
theoretically .. P 13.3, Π 30.4%. Bromine Number 682.

Gas chromatic analysis:

99 + weight percent ("AVP;

0 weight percent CAP.

Reproducibility of this procedure using three different samples from C AP:

96.5% yield
97.0% yield
97.2% yield

Average: 96.9 + 0.6%;

pH of the first wash water.
Moles of NaCl in the first wash water.
Moles of NaCl in the second wash water
Total number of moles of NaCl formed
Amount of converted to NaCl
Na ₂ CO ₃ 94%

2.0
0.975
0.020
0.995

Example 3
Procedural changes

Some of the reaction variables (time, temperature, amount of Na ₂ CO ₃ and acid catalyst) were examined.

A detailed study of the response variables was carried out in order to 1. determine the optimal conditions and 2. determine the rate of change in reaction rate as the sodium carbonate is consumed and only sodium acetate remains to effect hydrochlorination.

1. Response rate

The rate of COj release was at Reaction temperatures of 95 to 100 C and 120 C investigated. The reaction mixture contained KX) g of crude

is CAP (76% content). 19.66g Na ₂ CO, (theory) and 2.2 g acetic acid. Both reactions were started at room temperature. The CO ₂ was collected over 0.5 nH ₂ SO _4, and no corrections were made for the solubility of CO ₂ in 0.5nH ₂ SO ₄ and or deviations from standard conditions. The results are summarized in Table 2:

Table 2

If ^l > 5 to KK) (. »Ei no (. /.CIt aufycfaniicncs C <). ImIl 2 (XX) 10 350 28 (X) MXl 4200 30th 950 40 1450 43 (X) 50 2000 60 2400 70 80 3000 90 100 3500 110 120 3800 130 3850 " 40 50 3850

It has been observed that the rate of CO ₂ evolution between 80 to 90 and 120.degree. C. becomes quite high. As expected, the speed appears to double with a 1OX temperature increase. _{The difference in the amount of CO 2} captured at 12 (and 95 to 100 ° C) is due to the fact that CO _{3 was} slowly absorbed in the 0.5 nH ₂ SO ₄ , so that longer contact times reduce the volume observed, although the amount actually released is identical is.

2. Influence of different amounts of acetic acid

The influence of different amounts of acetic acid on the CAVP yield with pure CAP and the theoretical amount of Na ₂ CO ₃ in 3 hours of reaction time at 120 ° C. is shown in Table 3 again.

309 608 /:

Tubelle 3

Influence of acetic acid on the CAVP yield (using theoretical amounts of Na ₂ CO,

at 120 C and 3 hours)

acetic acid

(Mo! Mol
CAP)

0.05
0.2

Weight

uushcutu

Ig-KH) ι:

CAPl

82.4
85.2

gas chrome .Analysis (" _n CAVP) 1% CAI ¹ I. 9! 7th 8S 5

yield
!"/or
Theory)

87
87

The gas chromatographic analysis is based on a single gas chromatographic experiment international standard. The results are based on a comparison sample that is assumed to be 98% pure will. A reproducibility test on a sample gave 89, 88, 92 and 92 percent by weight CAVP (average: 90 t 4 percent by weight).

The results in Table 3 show no significant effect on the yield when 0.05 or 0.2 mole percent acetic acid can be used under the specified conditions. The results prove that acetic acid acts as a catalyst! '-.

3. Influence of different amounts of Na ₂ CO,

The influence of different Na ₂ CO, amounts on the CAVP yield when using crude CAP (76% content) and 10 mol percent acetic acid at different reaction times at 120 ° C. is shown in Table 4.

Table 4

Influence of the _{amount of Na 2} CO _r on the CAVP yield (with 10 mol percent acetic acid at 120 C.

and raw CAP)

15th 0.5 Acetic acid Gcwiclits-
yield gaschron . analysis Style. 1 (Mole mole (g / 100g % C'AV P % Return 1.5 CAI ¹ I. CAP) was standing 20 2 0.05 82.4 98 none 0.1 82.2 99 0.6 ') 0.1 81.8 89 9 0.1 78.2 98 2 ¹ )

The influence of the reaction time on the CAVP yield when using a 10% excess of Na ₂ CO and pure CAP at 120 C is shown in Table 5:

Table 5

Influence of the reaction time on the CAVP yield at 10% Na ₂ CO., At 120 "C

Yield% of theory

93 94 84 87

Ί - still residue. The gas chromatographic Analysis for% CAVP is based on the ratio of CAVP: CAP.

The results of Table 3 show that a 10% excess of Na ₂ CO, with pure CAP and 120 C in 1.5 to 2 hours, is harmful to the CAVP yield. The increase in backlog reflects this phenomenon. The detrimental effect of excess sodium carbonate with long reaction times at 2 ° C. is also expressed in the fact that more than the theoretical amount of NaCl is formed. This shows the amount as a function of the Na ₂ CO ₃ and the time

Table 6. Table 6

NaCl formed in the CAP conversion (pure CAF at 120 "C)

Moles of Na ₂ CO ₁ , Weight
exploitation gas chrome. yield Hours. 1% of Hours. 269 g analysis Theory) 45 raw CAP Ig HXIg 99 ³ CAP) 1% CAVP) (Comparison) 0.5 2 0.475 75.1 93 *) 99 1 89 ⁵ ° 2 0.5 0.5 76.4 86 97 0.5 1 0.5 75.7 78 97 1.5 2 0.5 75.7 86 96 0.5 0.5 0.525 73.9 85 94 55 1.5 1 0.525 77.1 82 89
t, T> 0.5 0.55 71.7 86 99 a ^]
77 of ra 1 0.55 71.8 84. 2 0.55 70.0 39

Na ₂ Cf) ₃ ol / mole CA.
acetic acid P. NaCl PH value
Laundry 0.5 0, 0.97 2.0 0.525 0. 0.99 3.6 0.525 0. 0.99 3.5 0.525 0, 0.04 1.6 0.55 0, 1.02 8.3 0.55 0, 1.03 7.0 0.55 0.97 9.9 0.55 0.99 9.5 0.05 0.05

*) This sample contained 0.9% CAP. which in all others Samples were missing.

The results of Table 4 show no advantage when using an excess of Na ₂ CO ₃ (more than 0.5 mol / 269 g CAP). If less than the theoretical amount of Na ₂ CO _{3 was used} , unreacted CAP remained in the product.

Yield '(% of theory)

94 81 85 81 82 84 93 86

') The yield is based on the gas chromatographic Weil of the raw product. This series of gaschromatographisct Analysis values had a wide scatter and could lead to ρ percentual CAVP yield values which were only 6% Table 6 shows that when more than 97% of the theoretical amount of NaCl is formed, the yield of CAVP is reduced will.

4. Influence of temperature

No significant difference in the CAVP yield could be found in reactions at 100 and 120 ⁰ C using the th

retic amount of Na ₂ CO. At 13ci 140 C there appeared to be an increase in the amount of residue formed, as Table 7 shows.

Table 7

Influence of the temperature ai.i the yield of CAVP (when using the theoretical amount of Na ₂ CO, 0.1 mol percent acetic acid, pure CAP)

Bulge

("n the theory)

*) Based on the (icwichlsausbeulL · der KX) C i Slundcn -Rcaktion. from which this sample was drawn after 1 hour.

¹ I Ciaschromatographisehe Analssc. based on the ratio of liis-, i: C'AP. What if the percentage residue is low.

5. Influence of Other Acid Catalysts The following other acids were also used examined and their usability determined:

V ¹ IlIp. Sill. (iettichiv
aushcuU " gasehrom \ nal \ se Residue (g UKI μ I (I CAl ¹ I. "" CAVI ¹ "" CAP 100 1 (84.5) *) 91..V) S. KM) 3 84.5 93 6th none 120 I. 82 9.V) 4th I. 140 1 S3 96 3.4

Acid catalyst

Heptane carboxylic acid

Benzoic acid

Pentachlorophenol.

results

97%
86%
88%

The acidic catalysts were in the 0.1 mole percent range under similar conditions as the

ίο acetic acid used.

Although it is not intended to theory the mechanism of implementation, the following may like Theory for the relationship of the invention be useful. It is believed that the alkali carbonate neutralizes the acidic catalyst present in the system with the formation of the corresponding alkali metal salt, and that these salts enter the surface of the organic phosphonate phase during the dehydrohalogenation takes place. The alkali metal halide formed during the neutralization precipitates. and the sour The catalyst is being regenerated. This process repeats itself until the end of the reaction, i. H. until that final phosphonate has formed and the alkali carbonate is used up. The acidic catalyst can be recovered unchanged, although expediently such a small amount of acid, as used here, conveniently washed out with the phosphate by washing with water can be.

Claims (4)

Patent claims: 1. Process for the preparation of α, / f-olefinic unsaturated alkylphosphonic acid esters by reacting a / i-chlorine (bromine, iodine) alkylphosphonic acid ester with a dehydrohalogenating agent at an elevated temperature, thereby characterized in that a mixture of (a) alkali metal carbonate is used as the dehydrohalogenating agent or alkali metal bicarbonate and (b) an organic acid, which is in 0.1 η solution 25 ° C has a pH of about 1 to about 6, in the molar ratio (a): (b) of about 25: 1 to about 2 ·. 1 used, the component (a) in a stoichiometric amount, based on the, / - Halogenalkylphosphonsäureester. or in a small excess and component (b) in an amount of 0.01 to 0.2 mol mol of .'-Haloalkylphosphonic acid ester can be used. 2. The method according to claim 1, characterized in that that sodium carbonate is used as the alkali metal carbonate. 3. The method according to claim 1, characterized in that that a molar ratio of (a): (b) of from about 10: 1 to about 4: 1 is used. 4. The method according to claim 1, characterized in that that acetic acid or pentachlorophenol is used as component (b).