DE2724261A1 - Alkene phosphonic acid di:ester prepn. - from epoxide and phosphorus tri:halide, used as intermediates for flame proofing agents for textiles and polyurethane - Google Patents

Abstract

The new esters are of formula (I): In (I), B is H, opt. substd. alkyl or alkenyl, R is H, opt. substd. alkyl, aryl or halogen; X is halogen, m is 0 or 1; n = 0, 1 or 2; B, R and X may be the same or different; >=1 B is opt. substd. alkenyl and =2 are unsubstd. alkenyl. Used as intermediates for the prepn. of flame-proofing agents (by halogen addition) for textiles made of natural and/or synthetic fibres, e.g. polyamides, cellulose, cellulose triacetate and partic. for polyester and cotton fibres; also for polyurethanes. These flame-proofing agents are wash-resistant.

Description

Phosphonic acid ester

The invention relates to alkene phosphonic acid diesters of the formula I in which B is hydrogen, optionally substituted alkyl or alkenyl, R is hydrogen, optionally substituted alkyl, aryl or halogen, X is halogen, m is 0 or 1 and n is 0, 1 or 2, and in which the substituents B, R and X can be identical or different, and in which at least 1 radical B is optionally substituted alkenyl and at most 2 radicals are unsubstituted alkenyl, and a process for their preparation.

In formula (I), the alkyl radicals contain in particular 1-6, preferably 1-4 carbon atoms, and the alkenyl radicals 2-4 carbon atoms. Preferred substituents are halogen atoms or hydroxyl groups. For example, there can be 1-4 substituents be present in the alkyl radical.

Halogen is understood to mean, in particular, chlorine or bromine.

Aryl stands in particular for phenyl which is substituted by 1-3 further radicals can be. Examples of substituents are halogen or C1-C4-alkyl.

Of the compounds of the formula (I) are those of the formula where n has the meaning given and B1 for hydrogen, C1 4 -alkyl or C2 4-alkenyl optionally substituted by chlorine or bromine, R1 for hydrogen, C1 alkyl, phenyl optionally substituted by chlorine, bromine or C14-alkyl and X1 for chlorine or Stand bromine and in which the substituents B1, R1 and X1 can be identical or different and at least one radical B1 represents the formula and at most 2 radicals B1 represent unsubstituted C2-C4-alkenyl, preferred.

The phosphonic acid esters I are prepared by reacting epoxy compounds of the formula III, optionally mixed with epoxides of the formula IV wherein R is as defined, Y is optionally substituted alkenyl and Z is hydrogen or optionally substituted alkyl, with the proviso that if Y is unsubstituted alkenyl, at least one further epoxide III, in which Y is substituted lkenyl, and / or an epoxide of the formula IV must be present, with phosphorus trihalide, in particular trichloride in a molar ratio of 3: 1 to 5: 1 in the temperature range between -200C and 1800C, preferably 200C to 80 ° C to tris (2-haloalkcnyl) phosphites and their Isomerization at temperatures between 800C and 2000C, preferably 110-1800C.

The reaction of the epoxy compounds or their mixtures takes place smoothly in quantitative yields in the temperature range between -200C to 1000C in a molar ratio of epoxide: phosphorus trihalide 3: 1 to 5: 1 in substance or in Presence of solvents which are inert towards phosphorus halides and epoxy compounds such as halogenated or halogen-free aliphatic and aromatic hydrocarbons, various ethers, carboxylic acid esters, etc. After the exothermic reaction has subsided if the reaction mixture is heated to 60-900C for a certain period of time, then it is still unreacted components react completely. Then excess epoxy is used distilled off. By heating the phosphite intermediate to temperatures between 80 and 2000C, preferably 110-1800C, the unsaturated ones are formed by rearrangement Phosphonates I. If the isomerization temperatures are too high, the formation increasingly wins of phosphorous acid diesters as a side reaction in importance.

The rearrangement reaction can also be carried out in the presence of 0.1 to 7 mol%, preferably 0.5 to 5 mol%, based on phosphite, of a finely divided nickel catalyst, such as nickel halides or carboxylates, nickel tetracarbonyl, II-allyl nickel halides, or carboxylates, Raney nickel or nickel acetylacetonate are carried out, what leads to a lowering of the temperature necessary for the rearrangement reaction.

According to a preferred embodiment of the method according to the invention is optionally added to the epoxy compound III presented in a 1 to 10% excess added dropwise in a mixture with IV phosphorus trihalide at such a rate that the reaction mixture boils gently. It is preferable to work in the presence of a the addition-catalyzing compound such as, for example, titanium acid orthoester or aluminum trialkyl. The mixture is then left to stir for 30-60 minutes and then exchanged the reflux condenser against a distillation bridge and heats the reaction mixture slowly to 75-90 ° C, with excess epoxy distilling off. The temperature is now gradually increased to 120 - 1800C. The rearrangement reaction occurs after 1-6 hours completed. After cooling to 80-1000C they may be in the reaction mixture volatile components contained in the vacuum removed.

In the case of reactions with epoxy mixtures, one must ensure that the epoxy compound initially added has completely reacted, as otherwise, especially with epoxy compounds with different reactivities in increased This could lead to the formation of inconsistent products.

According to a further preferred embodiment, the after Epoxy addition present phosphite stage long by a heated to 120 to 180 ° C Dummy film evaporator or a reaction tube sent, with the rearrangement in the phosphonates I and the removal of volatile constituents contained in the mixture occurs simultaneously; the residence time should be between 30 and 300 minutes. A preferred reaction condition for the uncatalyzed isomerization is e.g. 90 - 120 min. dwell time at 180 ° C.

Examples of epoxy compounds III include: 2- (1-chlorovinyl) oxirane, 2-chloro-2-vinyl-oxirane, vinyl-oxirane, 2-methyl-2-vinyl-oxirane and 2- (1-methylvinyl) -oxirane.

As epoxy compounds of type IV, for example, ethylene oxide, Propylene oxide, butylene oxide, epichlorohydrin, epibromohydrin, glycide and styrene oxide be mentioned.

Phosphorus trichloride and phosphorus tribromide are phosphorus halides called.

According to the new process, the phosphonic acid ester I succeeds simple manner in a one-step process without the occurrence of environmentally harmful To make by-products accessible.

The production of previously known alkene phosphonic acid esters took place according to different procedures. Older methods include the Michaelis reaction, i.e. the reaction of haloalkenes with sodium salts of phosphorous acid diesters in the presence of inert solvents (Houben Weyl 12/1, p. 446 ff) and the Arbusow reaction, i.e. the Conversion of haloalkenes with phosphorous acid triesters at higher temperatures with elimination of halogen alkenes (Houben Weyl 12/1, P. 433 ff).

Alkenphosphonate are still through the implementation of phosphorus trichloride with ethylene oxide to tris- (2-chloroethyl) phosphite, its thermal rearrangement 2-chloroethane phosphonic acid di- (2-chloroethyl) ester and its dehydrochlorination accessible in the presence of bases to di- (2-chloroethyl) vinylphosphonate. This compound can be converted into other vinyl phosphonates via intermediate stages. (US-PS 3,255,145, BE-PS 713 066).

The manufacturing methods listed so far are characterized by certain Disadvantages.

For example, when carrying out the Michaelis reaction one has to be in the presence anhydrous solvents work. It also increases the separation of the formed Sodium bromide or chloride as well as evaporation of the inert solvent the number the procedural steps, which complicates the whole method.

In the Arbusow reaction, environmentally harmful by-products occur Halogen alkenes, the elimination of which is expensive and associated with considerable problems is. In the dehydrohalogenation of 2-chloroethane-phosphonic acid di (2-chloroethyl) ester is split off, its neutralization and the subsequent Purification of the product represent additional process steps.

The formula I is idealized. According to IR and NMR spectroscopic investigations, because of the different possibilities for reacting the epoxy group with halogens, this is always an option the structures A and B existing reaction mixture, the composition of which varies greatly depending on the radicals Z and R and is very difficult to determine.

Preferred alkene phosphonic acid esters I are, for example and isomers and isomers and isomers and isomers and isomers and isomers """""""""""""Alkene phosphonic acid esters play a role as comonomers or intermediates in organophosphorus chemistry. They are accessible to the known olefin additions such as halogen additions, Diels-Alder addition, epoxidation or (co) polymerization.

The new phosphonic acid esters I are particularly valuable intermediates for flame retardants. These flame retardants are made from the phosphonic acid esters by halogen addition. This gives compounds of the formula I in which at least 1 radical B is>, β-dihaloalkyl. The flame retardants impart textile materials made of synthetic and / or natural fibers, e.g. polyamide, cellulose, cellulose triacetate and in particular polyester and cotton fibers are excellent against washing permanent flame protection. They are also used for the flame retardant finishing of polyurethanes usable.

The following examples serve to illustrate the invention, the indicated parts mean parts by weight.

The progress of the thermal rearrangement is easy in terms of IR spectroscopy to be followed by the increase in intensity of the P = 0 band at approx. 1250-1280 cm 1. the Thin-layer chromatographic separation of phosphites and corresponding phosphonates succeeds on silica gel plates using acetone / benzene mixtures as a flow agent.

Example 1 To 138 parts of phosphorus trichloride in 200 parts of chloroform 92.5 parts of epichlorohydrin and then 150 parts of vinyloxirane are added dropwise.

It is stirred for one hour at room temperature and the solvent distilled off.

365 parts of a mixture of mainly 20 is obtained nD = 1.5021 CH Cl P%%%% Calc .: 35.7 4.6 38.4 8.4 Found: 36.5 5.5 37.6 9.8 100 parts of this phosphite become added dropwise to a flask preheated to 160 ° C. and stirred for 4 hours at the same temperature.

98 parts of a phosphonate mixture are obtained, consisting mainly of the phosphonate of the structure consists; nD20 = 1.503.

Analysis: P Cl Calc .: 8.4 38.4 Found: 8.5 36.8 Example 2: 138 parts 190 parts of epichlorohydrin are slowly added to phosphorus trichloride at 20.degree. After 1 hour, 77 parts of vinyloxirane are added dropwise at 20-40 ° C. and left for 5 hours React at 20-300C. If the mixture does not react neutrally, add one add a small excess of epichlorohydrin. After neutralization has taken place, one draws the excess in a vacuum. The raw phosphite has the refractive index n20 = 1.507.

D The crude product is placed in a reaction vessel preheated to 1600C added dropwise and stirred at 1600C for a further 3 hours. The last ones are easy on the thin-film machine volatile components deducted.

A phosphonate mixture is obtained, consisting mainly of: nD20 = 1.5055 Example 3: 70 parts of vinyloxirane and then 116 parts of propylene oxide are added dropwise to 137.5 parts of phosphorus trichloride at 0 to 10 ° C. The mixture is warmed to 20-30 ° C., stirred for a further 4 hours at 20-40 ° C. and, if necessary, neutralized with a little propyleneoxyl. Volatile constituents are stripped off in vacuo, resulting in 310 parts of a phosphite mixture, which makes up approx. from the connection 2C D 20 consists; nD20 = 1.4819 Analysis: P Cl%% Calc .: 9.6 32,) Found: 9.6 32.1 The phosphite is added dropwise to a flask preheated to 160 ° C. and stirred at 160 ° C. for three hours. It is degassed in vacuo and a phosphonate mixture with the main components is obtained approx. 40 mol% 20 nD = 1.483 analysis: 19 P Cl%% calc .: 9.6 32.9 found: 10.3 29.5 Example 4: To 137.5 parts of phosphorus trichloride at 10-200C 56 Parts of propylene oxide and 147 parts of vinyloxirane were added dropwise. After stirring for four hours at room temperature, the mixture is concentrated in vacuo.

325 parts of a predominantly out 20 existing phosphite mixtures are obtained. nD = 1.4905 The isomerization (120 min / 1800C) likewise gives 315 parts of the phosphonate.

20 nD = 1.4990 Example 5 185 parts of epichlorohydrin are added dropwise to 271 parts of phosphorus tribromide and, after stirring for two hours at 50 ° C., 77 parts of vinyloxirane are added dropwise and the mixture is stirred at 50 ° C. for one hour. After a short treatment in vacuo, 520 parts (98.8% of theory) of a phosphite mixture nD20 = 1.5450 which predominantly consist of exists, but also contains certain proportions of the corresponding phosphonate (P = 0 band is at 1.332 cm. After stirring for four hours at 110 ° C., the isomerization is complete. 20 1.548.

nD = 1.548.

Example 6 92.5 parts of epichlorohydrin are added to 271 parts of phosphorus tribromide and after stirring for one hour at 40 ° C., 150 parts of vinyloxirane were added dropwise. Afterward the mixture is stirred for 4 hours at 50 ° C. and placed under vacuum.

487 parts (96.7% of theory) of the asymmetric phosphite, 20 with Portions of the phosphonate are obtained. nD = 1.5442.

The phosphonate mixture of the idealized formula is obtained by stirring for three hours at 1100C n20 = 1.5507 D Example 7: 137.5 parts of phosphorus trichloride are placed in the reaction vessel at about 30.degree. A mixture of 70 parts of vinyloxirane, 116 parts of propylene oxide and 3 parts of tetraethyl titanate is added dropwise. The exothermic reaction is controlled by cooling and throttling the feed rate, the temperature in the reaction mixture should be 30-400C. After the exothermic reaction has subsided, stirring is continued until the mixture reacts neutrally. The resulting phosphite is pumped into a vertically mounted reaction tube. It first passes through a pre-reaction zone heated to 1600C and then enters a second reaction area at 1800C. The residence time here should be 90 to 120 minutes. The overflow is fed into a thin-film evaporator operated at 100 to 1200C at approx. 10 mbar. The bottom discharge is identical to the product from Example 3.

Any residual acidity that may be present can be remedied by subsequent neutralization be buffered with propylene oxide before the thin layers.

Use Example 370 parts of the phosphonate obtained according to Example 1 dissolved in 1000 parts of chloroform with 320 parts of bromine in 1000 parts of chloroform implemented and stirred. After evaporating the solvent, 675 parts are obtained of the mixed halogen-containing phosphonate. Polyester fabric containing 5% by weight of this Product has been equipped according to conventional methods, has an excellent Flame retardant.

Claims (5)

Claims phosphonic acid esters of the general formula in which B is hydrogen, optionally substituted alkyl or alkenyl, R is hydrogen, optionally substituted alkyl, aryl or halogen, X is halogen, m is 0 or 1 and n is 0, 1 or 2, and in which the substituents B, R and X can be identical or different, and in which at least 1 radical B stands for optionally substituted alkenyl and at most 2 radicals for unsubstituted alkenyl. 2. Phosphonic acid esters of the general formula in which n has the meaning given and B1 is hydrogen, C1 1-4 -alkyl or C2-4-alkenyl optionally substituted by chlorine or bromine, R1 is hydrogen, C1-4-alkyl, phenyl optionally substituted by chlorine, bromine or C1-4-alkyl and X1 represents chlorine or bromine and in which the substituents B1, R1 and X1 can be identical or different and at least one radical B1 represents the formula and at most 2 radicals B1 stand for unsubstituted C2-C4-alkenyl. 3. Process for the preparation of phosphonic acid esters of claim 1, characterized in that epoxides of the general formula are used optionally in a mixture with epoxides of the general formula wherein R is hydrogen, optionally substituted alkyl, aryl or halogen, Y is optionally substituted alkenyl and Z is hydrogen, optionally substituted alkyl or alkyl, with the proviso that if Y is unsubstituted alkenyl, at least one further epoxide , where Y is substituted alkenyl, and / or an epoxide of the formula must be present, reacts with phosphorus trihalides to form phosphites and these isomerized to the compounds according to claim 1. 4. The method according to claim 3, characterized in that the Reaction of the epoxides with the phosphorus trihalide in the presence of a catalyst, in particular titanium acid orthoester or aluminum trialkyl carries out. 5. The method according to claim 3, 'characterized in that the Reaction of the epoxides with the phosphorus trihalide in a molar ratio of 3: 1 to 5: 1 im Temperature range between -200C and 180 ° C and the isomerization in the temperature range between 80 0C and 2000C.