IL45509A - 1,2-oxaphospholane-phosphonic acid esters their manufacture and their use as flameproofing agents - Google Patents

Description

Sew 1 2^oxaphosphplan0»ph 8phoiiic acid asters, their, icamifact re and thei uae as flameproofing agents CIBA-GEIGT AG,r C. 43563 The invention provides new 1 ,2-oxaphosphol.?ne-5-phosphonic acid esters, a process for their manufacture t a method of using them as flameproofing agents for thermopla stic polymers, polyurethanes , epoxy resins' ;'·' cellulose and cellulose derivatives and also, as industrial product, the substrates protected by them.

The nev7 compounds have the general formula I H wherein each of R^, R and R^ independently represents an alkyl, alkenyl, haloalkyl, alkoxyalkyl, cycloalkyl or a tetra-hydrofurfuryl radical, each of R^, and Rg independently represents hydrogen or alkyl or a phenyl radical optionally substituted with alkyl, alkoxy or halogen or is a furyl radical and R^ represents alkyl.

A radical represented by R^, or R^ can be a linear or branched alkyl or alkenyl radical, the alkyl radical being unsubstituted or substituted by halogen or alkoxy groups. Examples of such radicals are methyl, ethyl, iso-propyl, n-butyl, 2-ethylhexyl, isooctyl, n-dodecyl, n-octa-decyl, allyl, methallyl, oleyl, 2-chloroethyl, 2-bromoethyl , 45509/2 2 , 3-dibromopropyl , 2-ethoxyethyl , 2-butoxyethyl or 2-methoxy-propyl. Where these same substitutents represent a cycloalkyl radical, such a radical can be, for example, cyclo-pentyl, cyclohexyl or cyclooctyl.

Alkyl radicals represented by R4 , , Rg or R_. can be linear or branched alkyl radicals, e.g. methyl, ethyl, iso-propyl, tert.butyl, n-hexyl, 2-ethylhexyl , n-octyl, isooctyl, n-dodecyl or n-octadecyl. A phenyl radical may be unsubstituted or substituted by halogen, alkyl and/or alkoxy groups.

Preferred compounds are those of the formula I wherein each of R^, R2 and R^ independently represents alkyl with 1 to 18 carbon atoms, haloalkyl or alkoxyalkyl having not more than 18 carbon atoms, alkenyl with 3 to 18 carbon atoms, cycloaklyl with 5 to 8 carbon atoms, or R3 represents a tetrahydrofurfuryl radical, R^ represents hydrogen or methyl, R5 represents hydrogen, alkyl with 1 to 8 carbon atoms, phenyl which may be substituted by halogen, alkyl or alkoxy groups with 1 to 4 carbon atoms, or represents furyl, R represents 6 hydrogen, methyl or phenyl, and R7 represents alkyl with 1 to 8 carbon atoms. By halogen is meant in this context fluorine, chlorine or bromine.

Compounds of the formula I which constitute a special class of these compounds are those wherein each of R^ and R2 independently represents an alkyl, alkenyl or cycloalkyl radical, is the same as either R^ or R2, each of R4, R^ and R^ independently represents hydrogen, alkyl or a phenyl radical and R_ represents alkyl. 45509/2 To this class of compounds belong the compounds of the formula I wherein each of and independently represents alkyl with 1 to 18 carbon atoms, haloalkyl or alkoxy-alkyl having not more than 18 carbon atoms, alkenyl with 3 to 18 carbon atoms, cycloalkyl with 5 to 8 carbon atoms, R3 is the same as either R1 or R2, R4 represents hydrogen or methyl, R^ represents hydrogen, alkyl with 1 to 8 carbon atoms, phenyl which may be substituted by halogen, or represents furyl, Rc represents hydrogen, methyl or phenyl, and b R^ represents alkyl with 1 to 8 carbon atoms. 45509/2 * " ' " Particularly preferred compounds of the formula I are those wherein R^, and are identical and represent linear or branched alkyl radical with 1 to 8 carbon atoms, alkoxyalkyl with 3 to 6 carbon atoms, chloroethyl, bromo- ethyl, alkenyl with 3 or 4 carbon atoms, or cyclohexyl represents hydrogen or methyl, R-. represents hydrogen, methyl j ethyl , phenyl, chlorine and/or bromine substituted phenyl>tolyl, xylyl, anisyl or furyl, Rg represents hydrogen, and R-. represents methyl or ethyl.

Examples of individual compounds of the formula I are the following 1 ,2-oxaphospholane derivatives: 2-oxo-2-methoxy-5-me hyl-5-dimeth lphosphono-l ,2-oxaphos-pholane 2-oxo-2-ethoxy-5-methyl~5-dieth lphosphono-l ,2-oxaphospholane 2-oxo-2-isopropoxy-5-me h l-5-di-isoprop lphosphono-l,2-oxa-phospholane 2-oxo-2-butoxy-5-r.iethy1-5-dibutylphosphono- 1, 2-oxaphospholane · 2-oxo-2-octoxy-5-me hyl~5-dioct lphosphcno-l,2-oxaphos-pholane 2-oxo-2-(2-e hyl-hexyloxy)-5-tnethyl-S-di-(2-ethy lhexyl)-phosphono-1 ,2-oxaphospholane 2-oxo-2-octadecyloxy-5-meth 1-5-di-octadecylphosphono- 1,2- oxaphospholane 2-oxo-2-(2-chloroethyloxy)-5-methyl-5-di-(2-chloroethyl)- phosphono - 1 , 2-oxaphospholane 2Oxo-2-(2-methoxyethyloxy)-5-methyl-5-di-(2-methoxyethyl)- phosphono-l, 2-oxaphospholane 2-oxo-2-benzyloxy-5-methy1-5-di-benzylphosphono-l,2-oxaphospholane 2-oxo-2-methoxy-5-ethy1-5-diraethy lphosphono- 1 , 2-oxaphos- phola e 2-oxo-2-ethoxy-5-ethyl-5-dieth lphosphono- 1 ,2-oxaphospholane 2-oxo-2-methoxy-3,5-dimethyl-5-dimethylphosphono- ,2oxaphos-pholane 2-oxo-2-ethoxy-3,5-dimeth 1-5- die hylphosphono- 1,2-oxaphospholane 2-oxo-2-methoxy-3 ,4-dimethy1-5-dimeth lphosphono- 1,2-oxaphospholane 2-oxo-2-ethoxy-3,4-dimeth 1-5-diethylphosphono-l,2-oxaphospholane 2-oxo-2-methoxy-3 , 3 , 5- trimeth 1-5-dimethylphosphono- 1 , 2-oxa-phospholane 2-o>:o-2-ethoxy-3,3,5-trimethyl-5-diethylphosphono-l,2-oxa- phospholane 2-oxo-2-isopropoxy-3,3,5-trimethyl-5-di-isopropylphospbono- 1 ,2-oxaphospholane 2-oxo-2-butoxy-3 ,3 , 5- trime h 1-5-dibu lphos hono- 1 ,2-oxa- phospholane 2-oxo-2-(2-ethylhexyloxy)-3»3,5-l:rimethyl-5-di.-(2-ethylhexyl) phosphono- 1 ,2-oxaphospholane 2-oxo-2-(2-chloroethoxy)-3 ,3 ,5- rime hy1-5-di- (2-chloroethy1) phosphono- 1,2-oxaphospholane 2-oxo-2-cyclohexyloxy-3 ,3 ,5- trimethy1-5-dicyclohex lphosphono- 1 ,2-oxaphospholane 2 -oxo-2-methoxy-3-phenyl-5-methy1-5-dimethylphosphono- 1,2-oxaphospholane 2-oxo-2-ethoxy-3-phenyl-5-meth 1-5-diethylphosphono- 1,2-oxa-phosp olane 2-oxo-2-methoxy-3- (4-chlorophenyl) -5-me h 1-5-dime h lphosphono- 1 , 2- oxaphospholane 2-oxo-2-methoxy-3- (4-broiftophenyl)- 5-me h 1-5-dime hylphosphono- 1,2-oxaphospholane 2-oxo-2-methoxy-3- (4-methy lbenzyl)-5-methy1-5-dimeth lphosphono- 1,2-oxaphospholane 2-oxo-2-methoxy-3- (4-me hox phen l) -5-methy1-5-dime hylphosphono- 1 ,2-oxaphospholane 2-oxo-2-methoxy-3- (fury1-2) -5-methy1-5-dimethylphosphono- 1 , 2-oxaphospholane 2-oxo-2-methoxy-3--nethyl-5-(4-chlorophenyl)-5-dimethylphos- phono- 1,2-oxaphospbolane 2^-oxo-2-allyloxy-3 ,3 ,5- triiuethy1-5-diall lphosphono- 1 ,2-oxa-phpspholane 2-oxo-2-tetrahydrofurfuryl-3,3 ,5-trimethyl-5-di- (tetrahydro-furfuryl)-phosphono- (1 ,2-oxaphospholane The surprising discovery has been made that it is possible to manufacture the compounds of the formula I, in which is the same as R^ or , by a novel process which comprises reacting an α,β-unsaturated ketone of the formula (ID with at least 2 moles of a phosphite of the formula III 0 OR, ^ E - (in) -0R2 in the presence of a base, with or without the addition of a solvent.

Examples of a , β-unsaturated ketones of the formula II are methyl vinyl ketone, ethyl vinyl ketone, phenyl vinyl ketone, mesityl oxide, methyl isopropenyl ketone, benzalace-tone, benza lacetophenone or 4-chlorobenzalacetone . Such ketones can be manufactured by known methods, for example by condensation of the appropriate methyl ketones with aldehydes or ketones.

The phosphites of the formula III are known compounds of industrial availability. Examples thereof are di-alkyl phosphites, e.g. dimethyl, diethyl or dioctyl phosphite, dicycloalkyl phosphites, e.g. dicyclohexyl phosphite, diaralkyl phosphites, e.g. dibenzyl phosphite, and mixed phosphites, e.g. methyl butyl phosphite, methyl benzyl phosphite or isopropyl cyclohexyl phosphite.

In the reaction there are used 2 moles, preferably 2.5 to 3.5 moles, of a compound of the formula III for each mole of the compound of the formula II.

Examples of bases which catalyse the reaction are principally alkali metals, alkali metal or alkaline earth metal alkoxides, alkali metal amides and hydrides. Particularly effective are the metals sodium and potassium, sodium methoxide, potassium tert. butoxide, lithium amide and calcium hydride; but the two metals are particularly suit-able for the purpose. Normally, catalytic amounts of these bases suffice to initiate the reactio . 'It 'is sometimes advantageous to add further amounts of base during the reaction .

If the process according to the invention is carried out with the addition of a solvent, then suitable solvents are primarily hydrocarbons, e.g. benzene, toluene, xylene, ligroin, hexane or heptane, also alcohols, e.g. methanol, ethanol or isopropanol, or ethers, e.g. diethyl ether, dioxan or tetrahydrofuran .

The reaction can be carried out by dissolving the ketone of the formula II and adding dropwise a portion of the phosphite of the formula III and the base. Upon onset of the reaction, the remainder of the phosphite and, if necessary, further amounts of base; are added by gradual amounts. It is also possible to premix the phosphite with the catalyst and to add the ketone of the formula II dropwise.

In another embodiment, the compounds of the formula II and III and optionally the solvent are first mixed and then the base, which can also be dissolved in the solvent, is added to this mixture and the reaction is brought to comple-tion by heating.

The o aphospholanes of the formula I are isolated by customary methods, for example by distillation. Desirably the base is neutralised before the isolation by an equivalent amount of an acid, for example acetic acid.

The reaction of dialkyl phosphites wi h cx.p-un-saturated ketones has already been thoroughly investigated by various experts. It has hitherto been considered the rule that in the reaction only 1 mole of phosphite is added to the double bond forming the γ-ketophosphonates (see Houben-Weyl, Methoden der Organischen Chemie, vol. 12/1, pages 465-467, G. Thieme Verlag, Stuttgart, 1963). If diphosphonates were also obtained, these occurred in moderate yield in addition to the monophosphonates (A.N. Pudovik, Zhurnal Obshch. Khim. 22 (1952), 1371, ref. Chem. Abstr. 47 (1953), 4837). It was therefore surprising that in the process described herein 2 moles of phosphite are added easily. It was furthermore surprising that the γ-phosphono-o-hydroxyphosphonates evidently formed as intermediate cyclise under the reaction conditions rapidly and virtually completely to give the 1,2-oxaphospho-lane-5-phosphonates .

It has furthermore been found that oxaphospholane derivatives of the formula I can also be manufactured from the known γ-ketophosphonates by addition of dialkyl phosphites. This is an indication that the reaction discussed above probably proceeds via the stage of the γ-ketophosphonates . It is therefore possible to carry out the reaction in two partial steps, the first being the known addition of 1 mole of phosphite to a , β-unsaturated ketones to form the γ-ketophosphonates and the second being the reaction with a second mole of phosphite to form the oxaphospholanes . This second step is*^ just as surprising and novel as the single step main process.

The invention therefore also provides a process for the manufacture of compounds of the formula I, which comprises reacting a compound of the formula IV with at least one mole of a phosphite of the formula III in the presence of a base, with or without the addition of a solvent. In the formula IV, the subs ituents to have the same meanings assigned to them as in respect of the compounds of the formula I. The catalysts and solvents suitable for use in this process are the same as those for the single step main process described hereinbefore, and the reaction and isolation of the products are carried out in the same way.

This modification is principally of importance for the manufacture of those compounds of the formula I in which is different from R^ and R^- The compounds of the formula I are outstanding flameproofing agents for thermoplastic polymers, polyurethanes epoxy resins, cellulose and also for cellulose derivatives. It has long been known to use phosphorus-containing compounds as flameproofing agents for polymers, but it is normally neces sary to use the phosphorus compounds in high concentrations, which results as a rule in a deterioration of the physical Q™ and technological properties of the polymers.

The surprising discovery has now been made that the new 1,2-oxaphospholanes of the formula I impart an adequate flame resistance to the polymers even in relatively low concentrations. Moreover, on account of their considerable heat stability they have only a minute influence on the physi cal properties of the substrates. Further they are also usable in reactive systems, such as in polyurethane foams or in epoxy resins which, both in their manufacture and use, are highly sensitive towards additives.

Examples of thermoplastic polymers which can be flame-protected with the compounds of the formula I are: 1. Polymers which are derived from simply or doubly unsaturated hydrocarbons, such as polyolefins, e.g. polyethylene, polypropylene, polyisobutylene , polymethylbutene-l, polyme-thylpentene- 1 , polybutene- 1 , pol isoprene , polybutadiene , polystyrene, polyisobutylene , copolymers of the monomers based on the cited homopolymers , such as ethylene-propylene comonomers, propylene-butene- 1 copolymers, prop lene-isobu-t lene copolymers, styrene-butadiene copolymers, and terpoly-mers of ethylene and propylene with a diene, e.g. hexadiene, dicyclopentadiene or ethylidene riorbo nene; mixtures of the above mentioned homopolymers, e.g. mixtures of polyprop lene and polyeth lene, polypropylene and polybutene-1, polypropy- lene and polyisobutylene . 2. Halogen- containing vinyl polymers, e.g. polyvinyl polyvinylidene chloride, polyvinyl fluoride, but also poly-chloroprene and chlorinated rubbers. · ·"· 3. Polymers which are derived from , β-unsaturated acids and derivatives thereof, e.g. polyacrylates and polymethacrylates , polyacrylamides and polyacrylonitrile and copolymers thereof with other vinyl compounds, such as aery lonitrile/butadiene/ styrene, acrylonitrile/styrene and aerylonitrile/styrene/acry1-ic ester copolymers. 4. Polymers which are derived from unsaturated alcohols and amines and their acyl derivatives or acetals, such as polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate, polyvinyl butyral, and copolymers thereof with other vinyl compounds, e.g. ethylene/ vinyl acetate copolymers. 5. Polyacetals, e.g. polyoxymethylene and polyoxyethylene , and also those polyoxymethylenes that contain ethylene oxide as comonomer. 6. Polyphenylene oxides. 7. Polycarbonates. 8. Polysulphones . 9. Polyamides and copolyamides which are derived from diamines and dicarboxylic acids and/or aminocarboxy lie acids or from the corresponding lactams, e.g. polyamide 6, polyamide 6/6, polyamide 6/10, polyamide 11, polyamide 12. 10. Polyesters which are derived from dicarboxylic acids and dialcohols aiid/or the corresponoing lactones, e.g. poly^ ethylene glycol terephthalate, polybutylene terephthalate , poly-l,4-dimethylol-cyclohexane terephthalate.

The flameproofing of cellulose and cellulose derivatives is possible in those cases where the polymer is processed from solution or from the melt, so that the flameproof-ing agent can be added to this solution or melt. The cellulose xanthogenate solutions which are known as viscose solutions and which are used for the manufacture of fibres and sheets of regenerated cellulose are one example. Solutions of cellulose acetate in organic solvents are another example.

Polyurethanes which can be given a flameproof finish with the compounds of the formula I can be both linear and branched polyurethanes such as are used for the manufacture of films, fibres, brushes, coatings, elastic materials and rigid and soft foam plastics. The flameproofing of polyure-thane foam plastics is of particular importance since such foams, like all materials having a large surface area, burn more easily than compact materials.

It is common knowledge that such polyurethane foams or coating compositions are manufactured from polyhydroxy compounds, e.g. polyesters or polyethers which contain hydroxy groups on the one hand and polyisocyanates , e.g. toluylene diisocyanate , on the other. The introduction of flameproofing agents of the formula I can be accomplished by adding them to the starting components mentioned hereinbefore, i.e. simultaneously with the manufacture of the polyurethanes , since the oxaphospholane derivatives scarcely influence the pot life and curing time. Non-inflammable polyurethane foam plastics or coatings with excellent mechanical properties and very good resistance to ageing are thereby obtained.

The same applies to the flameproofing of epoxy resins. These resins are usually manufactured by mixing an epoxide component with a hardener component, whereupon a poly-addition reaction takes place between the two components. The flameproofing agents of the formula I can be mixed both with the epoxide and with the hardener component since they are compatible with both and such mixtures are storable. But it is also possible to add the flameproofing agent only during the manufacture of the resin as third component so long as the resin is still liquid and not yet formed.

Epoxy resins are used frequently in those cases where a high thermal stability of a resin under load is required. Many organic flameproofing agents, for example phosphorus esters or chloroparaffins , effect a perceptible reduction in the thermomechanical stability of epoxy resins. However, such small amounts of the compounds of the formula I are required for an effective flameproofing of epoxy resins that the thermomechanical stability of these latter is not noticeably impaired.

The compounds of the formula I are normally added to the cited substrates in an amount of 2 to 30% by weight, preferably 2 to I07o by weight, based on the substrate. The addition can be carried out before or during the manufacture' of the substrate by polymerisation; but frequently the com-pounds are added to the finished polymers before or during their processing.

In addition to the flameproofing agents of the formula I, it is also possible to add to the polymeric substrates other flameproofing agents, e.g. organic halogen compounds, antimony oxide or other phosphorus compounds. It is furthermore possible to add other customary and known additives, e.g. antioxidants, heat stabilisers, UV absorbers fluorescent brighteners, antistatic agents, lubricants, soft eners, emulsifiers , pigments, carbon black, asbestos, kaolin talcum, glass fibres or other fillers and reinforcing agents The manufacture and utility of the oxaphospholanes of the formula I are illustrated in more detail in the following Examples.

Example 1 Preparation of 2-Oxo-2-ethoxy-3 ,3 , 5- rimethy1-5-dieth lphc^ phono- 1 ,2-oxaphospholane 10 ml of diethyl phosphite are added to a solution of 98.1 g (1 mole) of mesityl oxide in 300 ml of benzene and the mixture is then heated to 80°C. About 200 mg of metallic sodium are added to the almost boiling solution, whereupon an exothermic reaction commences. The reaction is brought to completion over the course of 10 minutes by gradual addition of altogether 345.0 g (2.5 moles) of■ diethyl phosphite and 4.2 g of sodium. The reaction mixture is stirred for further 10 minutes, neutralised with 11 g of glacial acetic and evaporated in vacuum. The residue is distilled in a high vacuum. The main fraction distills as an almost colourless oil at 136°-139°C and 0.035 mm Hg. After analysis, nuclear magnetic resonance and mass spectrum this fraction is 2-oxo-2-ethoxy-3 ,3 ,5- trimethyl-5-diethylphosphono-l,2-oxaphospholane of the empirical formula C-^H^O^ (M = 328.29).

Analysis : calc: C 43.90 H 7.99 P 18.92 found: 44.30 8.00 18.0 The yield is 45.370 of theory.

The same reaction is carried out with 392 g (4 moles) of mesityl oxide and 1660 g (12 moles) of diethyl phosphite in 12.00 ml of benzene and in the presence of 9.5 g of sodium.

Upon completion of the reaction (40 minutes) , the reaction mixture- is neutralised with 24.8 g of glacial acetic acid'"^ and distilled to yield 995.7 g of 2-oxo-2-ethoxy~3 ,3 , 5- tri- o ( ,.. meth l-5~dieth}7lphosphone-l,2-oxaphosph'olane which melts at 136°-140°C at 0.02-0.04 Torr. This corresponds to a yield of 75.9% of theory.

Example 2 Preparation of 2-0xo-2~methoxy-3 ,3 , 5- trimethy1-5-dimethy1- o phosphon^- 1 , 2-oxaphospholane A solution of 30.0 g of sodium methoxide in 90 ml of methanol is added dropwise to a mixture of 220 g of dimethyl phosphite and 98 g of mesityl oxide over the course of 2 hours in such a way that the reaction temperature does not exceed 6 °C.

The clear solution is subsequently heated for 2 hours to 70°C. The reaction mixture is concentrated in vacuo and the residue is taken up in 200 ml of toluene. The solution is filtered and the filtrate distilled. The 2^oxo-2-methoxy-3 ,3 ,5- trimethyl-5-dimethylphosphon^-l,2-oxaphospholane distills at 158°-160°C in the form of a colourless, viscous oil.

Analysis, 'calc. for (M = 286.20) calc: C 37.80 H 7.05 P 21.65 found: C 37.79 H 7.04 P 21.32 Example 3 Flameproofing of a polyurethane foam A soft polyurethane foam is manufactured b mixing the following materials: 100 g of a polyhydroxy compound on a polyether basis with a molecular weight of about 3000 and a OH number of 56 1 g of a siloxane-ox alkylene copolymer 0.1 g of tin (II) octoate 3.5 g of water 48.2 g of toluylene diisocyanate (80:20 mixture of the 2,4-and the 2,5-isomers) x g of 2-oxo-2-ethoxy-3 ,3 ,5- trime hy1-5-diethylphosphono- 1 , 2-oxaphospholane (compound of Example 1).

The foam so manufactured is tested for its flamma-bility by the ASTMD 1692 test method. For this purpose, test specimens each measuring 150 mm x 50 mm x 13 mm are fixed with thefl.50 mm x 4-3^ mm surface in the horizontal position.

Marks are made at 25 mm and 100 mm. The bottom end of the specimen is then ignited with a gas burner. The ignition time is 60 seconds. The foam is termed flameproof if the burned zone is not longer than 25 mm. If the specimen burns beyond the 25. mm mark and the burned zone is smaller than 125 mm, then the foam is termed self-extinguishing. The length of the burned zone is indicated in mm. If the specimen burns bejond the 125 mm, the foam is termed combustible.

Amount of x g of flameproofing agent/100 g polyol a) foaming behaviour - creaming time in seconds - rise time in seconds - time in minutes until foam is no longer tacky b) flammability (ASTM D 1692) burned zone in mm rate of combustion in mm/sec.

These figures show that a storage resistant flameproofing is obtained with 2-oxo-3 ,3 ,5- trime hyl~5-diethylphosphone-l,2- , oxaphospholane even if only 4 g of this compound per 100 g of polyol is used. ' ' ' ■ Example 4 2-0x0-2-ethoxy-3 ,3 ,5- trimethy1-5-dieth lphosphono- 1,2-oxaphospholane 98 g of mesityl oxide (1.0 mole) and 415 g of diethyl phosphite (3.0 moles) are dissolved in 300 ml of benzene and 200 ml of this solution are heated to the boil. A catalytic amount of sodium is added whereupon a vigorous exothermic reaction commences and the mixture boils by itself after removal of the heating bath. After the sodium has dissolved the reaction comes practically to a stop and is initiated a fresh by addition of a further amount of sodium. In this manner sodium is added until the main reaction is over. Then about one third of the remaining solution is passed in and this is reacted as previously by adding sodium. The remaining two thirds of the solution are reacted in the same way. Altogether 3.0 g of sodium are used over the course of 25 minutes. The reaction mixture is allowed to continue to react for 15 minutes at boiling temperature, then it is neutralised with 8 g of glacial acetic acid and diluted with 350 ml of benzene. After the reaction solution has cooled, it is washed- with two portions of water of 75 and 20 ml respectively. The combined aqueou^; phases are extracted with 50 ml of benzene twice to give a solution in benzene which is combined with the chief portion, dried with and concentrated in a rotary evaporator.

Distillation yields 118.5 g of first runnings of b.p. 46°-68°C/8 mm Hg, which largely consists of diethyl phosphite, and 280.8 g (85.670 of theory) of the oxaphospholane which boils at 122°-132°C at 0.008 mm HG. Gas chromatography shows the product to be about 95% pure. 8.2 g remain as distillation residue.

Example 5 2-0x0-2- isopropoxy-3 ,3 ,5- trimethy1-5-diisopropylphosphono-l ,2-oxaphospholane As described in Example 4, a mixture of 19.6 g of mesityl oxide (0.20 mole), 99.6 g of diisopropyl phosphite (0.60 mole) and 100 ml of benzene is reacted with 2.1 g of sodium as catalyst over the course of 10 minutes. The reaction is vigorously exothermic. After a subsequent reaction of 15 minutes at boiling temperature the reaction mixture is neutralised with 5.5 g of glacial acetic acid and diluted with 150 ml of benzene. After the reaction solution has cooled it is extracted with 20 ml of benzene twice and the extract is com-v V bined with the chief portion, dried over and concen- trated in a rotary evaporator. The distillation yields 27.5 of first runnings with a boiling point of 68°-75°C/10 mm Hg and consisting of virtually pure diisopropyl phosphite as well as 58.0 g (78.3%) of the oxaphospholane which boils at 120%).02 mm Hg to 125°C/0.05 mm Hg; 5.3 g remain as reside Analysis, for C-^H^O^ (M = 370.37) calc: C 48.64 H 8.71 P 16.73 found: C 48.77 H 8.92 P 16.37 The mass spectrum shows the molecular peak at m/e 370.

Example 6 2-0xo-2-ethoxy-4 ,5-dimethy1-5-diethyIphosphono- 1 ,2-oxaphos-pholane In analogous manner to Example 4, a mixture of 25 g of freshly distilled methyl isopropenyl ketone (0.30 mole), 124 g of diethyl phosphite (0.90 mole) and 75 ml of benzene are reacted with 2.5 g of sodium over the course of 10 minutes. The reaction is vigorously exothermic. After a subsequent reaction of 10 minutes at boiling temperature, the reaction mixture is neutralised with glacial acetic acid and diluted with 300 ml of benzene. After the reaction solution has cooled, it is extracted with 60 ml of 1^0. Thy aqueous phase is extracted twice with 60 and 30 ml of benzene respectively and the ex tract is combined with the chief portion^ dried over N 2S0^ and concentrated in a rotary evaporator. The distillation yields 49.2 g (52.2% of theory) of the oxaphospholane of b. p. 128°-132°C/0.002 mm Hg.

Analysis, for (M = 314.26) calc: C 42.04 H 7.70 P 19.71 found: C 41.78 H 7.69 P 19.39 The mass spectrum shows the molecular peak at m/e 314.

Example 7 2-Oxa-2-butoxy-3 ,3 ,5- trimeth 1- 5-dibuty lphosphono- 1 ,2- oxaphospholane A reaction solution is prepared from 194 g (1 mole) of freshly distilled dibutyl phosphite and 32.4 g (0.33 mole) of mesityl oxide in 200 ml of absolute benzene. 30 ml of this mixture are put into the reaction flask and treated with about 50 mg of sodium. An exothermic reaction commences and the temperature rises to 70°C. After the reaction has subsided, the reaction mixture is brought to reflux temperature by addition of reaction solution in small amounts and of 1.5 g of sodium. Stirring is continued for 1 hour at 70°C and the reaction mixture is subsequently neutralised with glacial acetic acid.

Distillation yields the product with a boiling point of 158°-162°C/0.01 mm.

Example 8 2-Oxa-2-cyclohexoxy-3 ,3,5- rimeth 1-dicyclohexylphosphono-1 ,2-oxaphospholane 88 g (0.35 mole) of freshly distilled dicyclohexyl phosphite are dissolved in 150 ml of absolute benzene and the solution is warmed to 50°C. After addition of 2 g of sodium, 15 g (0.14 mole) of freshly distilled mesityl oxide are added drop-wise. The exothermic reaction causes the temperature of the mixture to rise to 70°C. After termination of the reaction, the reaction mixture is stirred for further 2 hours and then neutralised with glacial acetic acid. The filtered solution is distilled and the product with a boiling point of 150°-153°C/0.01 mm Hg is obtained.

Example 9 2-Oxo-2-ethoxy-3 ,3,5- rimeth 1-5-die hy Iphosphono- 1 ,2-oxa- ^ phospholane 690 g of diethyl phosphite and 50 g of a sodium methoxide solution (17 g of sodium dissolved in 83 g of ethanol) are mixed in a sulphurating flask. With stirring, 245.5 g of mesityl oxide are dropped into this solution over the course of 40 minutes. During the dropwise addition an exothermic reaction takes place, the reaction temperature rising from 20°C to 101°C when up to half the amount of mesityl oxide has been added. The temperature then falls to 75 °C when the second half of the mesityl oxide is added. The colourless, clear solution is stirred for 50 minutes and the temperature in the reaction mixture falls to 39°C. Then a further 25 g of sodium methoxide solution are added all at once, whereupon the temperature of the reaction mixture rises from 39° to 84°C. The reaction mixture is stirred for 30 minutes and then 25 g of sodium methoxide solution are added. The resultant reaction mixture is stirred for 3 hours at room temperature and subsequently neutralised with 15 g of glacial acetic acid. Distillation of this reaction mixture yields at 162°-167°C/0.5 mm 626 g of 2-oxo-2-ethoxy-3 ,3 ,5- trimethy1-5-di-ethylphosphono- 1 ,2-oxaphospholane as a colourless liquid. Chromatographic, analysis shows a purity of 99.1%.

Example 10 2-0xo-2-e hoxy-5-methy1-5-diethy lphospho.no- 1 ,2-oxaphosphol-T 276 g (2 moles) of freshly distilled' diethyl phosphite are treated with a solution of 3.5 g of sodium methoxide in 20 ml of absolute ethanol and 70 g (1 mole) of freshly distilled methyl vinyl ketone are added dropwise thereto. The exothermic reaction causes the temperature of the mixture to rise to about 70 °C. After the whole amount of methyl vinyl ketone has been dropped in, stirring is continued for 2 1/2 hours and the reaction mixture is neutralised with glacial acetic acid.

After a first runnings which consists largely of diethyl phosphite and methyl vinyl ketone, the distillation at 0.01 mm yields the product with a boiling point of 120°-133°C.

Example 11 2-0xo-2-ethoxy-5-eth 1-dieth lphosphono- 1 ,2-oxaphospholane 138 g (1 mole) of freshly distilled diethyl phosphite are treated with a solutio of 1.75 g (0.075 mole) of sodium in 10 ml of absolute ethanol and 42 g (0.5 mole) of ethyl vinyl ketone are added dropwise thereto. The exothermic reaction causes the temperature of the mixture to rise to 70°C. After the whole amount of ethyl vinyl ketone has been dropped in, the reaction is brought to completion by adding once more 1 g (0.04 mole) of sodium in 10 ml of absolute alcohol when again a rise in temperature to 60°C is observed. Stirring is con- ; tinued for 2 hours and the reaction mixture is then neutra-lised with glacial acetic acid. After a first runnings which consists largely of diethyl phosphite and ethyl vinyl ketone, the distillation at 0.1 mm yields the product having a boiling point of 132°-138°C.

Example 12 2-0xo-2-ethoxy-3-phen 1-5-meth 1-5-diethylphosphono- 1 ,2-oxaphospholane 276 g (2 moles) of freshly distilled diethyl phosphite are treated with a solution of 3.5 g (0.15 mole) of sodium in 20 ml of absolute ethanol. At 40°C, 146 g (1 mole) of benzal acetone are dissolved in 50 ml of absolute ethanol and this solution is added dropwise to the first solution. The exothermic reaction causes the temperature of the mixture to rise to 90°C over the course of 1 hours. After completion of the addition of benzalacetone , the reaction mixture is stirr for 3 hours and neutralised with glacial acetic acid. The product is isolated in the subsequent distillation at 187°-210°C/0.01 mm.

Example 13 2-Oxo-2-ethoxy-3 ,3 , 5- trimethy1-5-die hyIphosphono- 1 ,2-oxa-\ ? phospholane 10 ml of a mixture of 70.8 g of 4-methyl-4- (diethylphosphono) pentanone-2 (prepared from mesityl oxide and diethyl phosphite) and 82.8 g of diethyl phosphite are dissolved in 100 m of toluene and the solution is heated to 80°C. A catalytic amount of sodium is added and a vigorous exothermic reaction commences. The reaction temperature is held between 80 °C and 90°C by alternately adding the previously prepared mixture and small pieces of sodium. Altogether 1.65 g of sodium are used as catalyst. The reaction takes 20 minutes. The reaction mixture is subsequently stirred at 80°C-90°C for 30 minutes with heating, then cooled and neutralised with 4.5 g of glacial acetic acid. This reaction mixture is distilled to yield 2-oxo-2-ethoxy-3 ,3 ,5-trimethyl-5-diethylphosphono-l,2-oxaphospholane with a boiling point of 156 °C- 161°C/1.1 mm. This substance is identical with the oxaphospholane manufactured according to Example 4.

Example 14 2-Oxo-2-ethoxy-3 ,3 ,5- trimethy1-5-dime th lphosphono- 1 ,2-oxaphospholane By carrying out the same procedure as described in Example 13, 2-e.thoxy-3 ,3 ,5- trime hy1-5-dimethyIphosphono- 1 , 2-oxaphosphi?-/ lane with a boiling point of 146°-148°C/0.5 mm is obtained from 70.8 g of 4-methy1-4- (diethyIphosphono) -pentanone-2- and 66.0 g of dimethyl phosphite with 1.65 g of sodium as catalyst.

Example 15 2-Oxo-2-ethoxy-3 ,3 ,5- trimethy1-5-di- (isopropy l)-phosphono- 1 ,2-oxaphospholane By carrying out the same procedure as described in Example 13 , 2-ethoxy-3 ,3 , 5- trimethy1-5-di- (isopropyl)-phosphono- 1,2-oxaphospholane with a boiling point of 180°-185°C/2 mm is obtained from 70.8 g of 4-methy1-4- (diethy Iphosphono) -pentanone-2 and 99.6 g of diisopropyl phosphite with 4.6 g of sodium as catalyst.

Example 16 2-Oxo-2-methoxy-3 ,3 ,5- trimethy1-5-diethyIphosphono- 1,2-oxa-phospholane By carrying out the same procedure as described in Example 13 , 2-oxo-2-me hox3'-3 ,3,5- trimethy 1-5-diethyIphosphono- 1,2- oxaphospholane with a boiling point of 144°-146°C/0.6 mm is obtained from 83.2 g of 4-methyl-A- (dim thylphosphono)-pen-tanone-2 and 110.4 g of diethyl phosphite with 1.15 g of so-dium as catalyst. The P 31■ spectrum shows' for the phosphorus atom in the 5-ring a shift of -48 ppm compared with H^PO^ as standard.

Example 17 2-Oxo-2-ethoxy-3 ,3 ,5- trime h l-5-di- (isooc yl) -phosphono- 1,2-oxaphospholane By carrying out the same procedure as described in Example 13, 2-oxo-2-ethoxy-3 ,3 ,5- trimethy1-5-di- (isoocty1) -phosphono- 1 ,2-oxaphospholane is obtained as a viscous, colourless oil from 47.2 g of 4-meth l-4- (diethylphosphono)-pentanone-2 and 84.6 g of di-isooctyl phosphite with 1.15 g of sodium as ca~ 31 talyst. The P spectrum of this oil shows for the phosphorus atom in the ring a shift of -49 ppm compared with H^ O^ as standard.

Example 18 2-Oxo-2-ethoxy-3 ,3 ,5- trimethy1-5-di-n-octylphosphono-1, 2-oxa-phospholane By carrying out the same procedure as described in Example 13 , 2-oxo-2-ethoxy-3 ,3 ,5-trime hyl-5-di-n-octylphosphono~12 , -oxaphospholane is obtained as a viscose, pale yellow oil from 47.2 g of 4-methy1-4- (diethylphosphono) -pehtanone-2 and 84.6 g of di-n-octylphosphite with 1.15 g of sodium as cata-lyst. The P31 spectrum of this oil shows for the phosphorus atom in the ring a shif of -49 ppm compared with HLPO, .

Example 19 2-Oxo-2-ethoxy-3 ,3 , 5- rimethy1-5-di- (2-chloroethyl) -phosphono-1 ,2-oxaphospholane By carrying out the same procedure as described in Example 13, 2-oxo-2-ethoxy-3 ,3 ,5- trimethy1-5-di- (2-chioroethy1) -phosphono-1 ,2-oxaphospholane is obtained from 47.2 g of 4-methy1-4- (diethylphosphono)-pentanone-2 and 45.2 g of bis (2-chloroeth l) - 31 phosphite. In the P spectrum, this compound shows for the phosphorus atom in the ring a shift of -50.2 ppm compared with H P0, as standard.

Example 20 2-Oxo-2-propyloxy-3 ,3 ,5- trimethy1-5-dipropylphosphono-l ,2-oxaphospholane 11.8 g of mesityl oxide and 9.8 g of dipropyl phosphite are heated in 40 ml of betizene to 80°C. At this temperature, Vy 0.1 g of sodium is added, whereupon an exothermic reaction commences. The reaction temperature is held at 80°-90°C with external heating by alternately adding 40.0 g of dipropyl phosphite and 0.4 g of sodium. After all the sodium has been added, stirring is continued for 30 minutes, the reaction mixture is cooled and neutralised with 1.4 g of glacial acetic acid. The reaction mixture is concentrated in a rotary evaporator and then distilled in a high vacuum to yield 2-oxo-2-ethoxy-3 ,3 , 5- trimethy1-5-dipropyIphosphono- 1 ,2-oxaphos-pholane in the form of a colourless oil with a boiling point 31 of 153°-154°C/0.1 mm. The P spectrum shows for the phosphorus atom in the ring a shift of -67.2 ppm compared with triphenylphosphate as standard.

Example 21 2-0x0-2- (2-methoxyethoxy)-3 ,3 ,5- rimethy1-5-di- (2-methoxyethy1) -phosphono- 1 ,2-oxaphospholane 15.7 g of mesityl oxide and 9.2 g of di- (2-me hoxyethy1) -phosphite are heated to 80°C in 50 ml of benzene. At this temperature, 0.1 g of sodium is added whereupon an exothermic reaction commences. The reaction temperature is held between 80°- 90°C without external heating by alternately adding 70.0 g of di- (2-methoxyeth l) -phosphite . and 0.6 g of sodium. After all the sodium has been added, he reaction mixture is stirred for 30 minutes at 80°C, cooled and 'neutralised with 1.75 g of glacial acetic acid. The reaction mixture is concentrated in a rotary evaporator and the residue is distilled in a high vaccum to yield 2-oxo-2- (2-methoxyethoxy) -3 ,3 , 5- trimethy1-5-di- (2-methoxyethyl)-phosphono-l,2-oxaphospholane in the form of a colourless oil with a boiling point of 193°- 196°C/0.07 mm.

The P31 spectrum shows for the phosphorus atom in the ring a shift of -67.2 ppm compared with triphenylphosphate as standard.

Example 22 2-0xo-2-allyloxy-3 ,3 ,5- trimethy1-5-diallylphosphono-l ,2-oxaphospholane 11.5 g of mesityl oxide and 7.4 g of dially phosphite are heated to 80°C in 40 ml of benzene. At this temperature, 0.1 g of sodium is added. An exothermic reaction starts and the reaction temperature is held at 80°-90°C without external heating by alternately adding 40.0 g of dially phosphite and 0.4 g of sodium. After all the sodium has been added, the reaction mixture is stirred for 30 minutes at 80°C, then cooled and neutralised with 1.3 g of glacial acetic acid. The reaction mixture is concentrated in a rotary evaporator to yield as residue 2-oxo- 2-allyloxy-3 , 3 , 5- trimethyl- 5-dially 1phospho o-'^ 1 , 2-oxaphospholane in the form of a pale yellow oil. The P 1 spectrum shows for the phosphorus atom in the ring a shift of - 68 . 5 ppm compared with triphenylphosphate as standard.

Example 23 2-Oxo-2-ethoxy-3- (4-methoxypheny 1) - 5-methy 1-5-diethylphos-phono- 1 , 2-oxaphospholane A mixture is prepared of 69 .0 g of diethyl phosphite and 5 g of a 177o sodium ethoxide solution in ethanol. To this reaction mixture are added in small amounts 44 g of p-methoxy-benzalacetone , whereupon the temperature rises from 25 °C to 89°C . The reaction mixture is stirred for 50 minutes and then a further 2 . 5 g of the 177» sodium ethoxide solution are added. After a further 30 minutes 3 . 5 g of diethyl phosphite and 2 . 5 g of sodium ethoxide solution are added to give a pale yellow, clear solution which is concentrated ■ in a rotary evaporator. 31 The P spectrum for the phosphorus atom in the ring of the 2-oxo-2-ethoxy shows a shift of -58 ppm compared with triphenyIphosphate .

Example 24 2-Qxo-2-ethoxy-3- (4-methy Ipheny 1) -5-methy1-5-diethy Iphosphoir.o-1 ,2-oxaphospholane By carrying out the same procedure as described in Example 23 , 2-oxo-2-ethoxy-3- (4-methy Ipheny l)-5-methy 1-5-diethy Ipho-phono- 1 ,2-oxaphospholane is obtained from 30.2 g of 4-methy 1-benzalacetone and 54.7 g of diethyl phosphite with 7.8 g of 31 a 17% sodium ethoxide solution in ethanol, The P spectrum of the product shows a shift of -58 ppm for the phosphorus atom in the ring.

Example 25 2-0xo-2-e hoxy-3- (4-chlorophen 1)- 5-me hy 1-5-diethyIphos-phono- 1 , 2-oxaphospholane By carrying ou the same procedure as described in Example 23 , 2-oxo-2-ethoxy-3- (4-chloropheny1) -4-methy 1-5-diethyIphos-phono-l,2-oxaphospholane is obtained from 45.2 g of 4-chloro-benzalacetone and 72.5 g of diethyl phosphate with 10 g of a 31 17% sodium ethoxide solution in ethanol. The P spectrum of the product shows a shift of -57.5 ppm for the phosphorus atom in the ring compared with triphen Iphosphate .

Example 26 2-Oxo-e.thoxy-3- fury1-5-methyl-diethyIphosphono- 1 ,2-oxaphos- '■ pholane By otherwise carrying out the same procedure as described in Example 23, 2-oxoethoxy-3-fury1-5-methy1-diethyIphosphono- 1 ,2-oxaphospholane is obtained from 34.0 g of furfurylidene acetone and 72.5 g of diethyl phosphite with 10 g of a 17% sodium ethoxide solution in ethanol. The P 31 spectrum of the product shows a shift of -55.3 ppm for the phosphorus atom in the ring compared with triphenylphosphate .

Example 27 Flameproofing of polyethylene terephthalate 15 parts of a commercially available polyethylene terephthalate are dissolved in 85 parts of hexafluoroisopropanol . This solution is mixed with the corresponding amount of flame-proofing agent and stirred until it is homogeneous. Using a film drawing rod, half of the solution is applied to a glass plate to a thickness of 0.5 mm. A glass cloth is then pressed on the film and is coated by the second half of the solution in a thickness of 1 mm. Drying in vacuo at 120°C over 16 hours is subsequently effected. The dried film is drawn from the glass plate and the flammability is determined by the LOI method described by CP. Fenimore and J.F. Martin in "Combustions and Flame" 10, No. 2, 135-139 (June 1966). ^ . In this test, the film is ignited' in an atmosphere of nitrogen and oxygen of different volume composition and the volume ratio is ascertained at which it is still just possible to maintain combustion of the test specimens. The LOI value is the minimum oxygen concentra ion in a nitrogen-oxygen mixture at the specimen just still burns. The higher the LOI value the lower the flammability of the sheeting, i.e. the more effective the addition of flameproofing agent. * based on polyethylene terephthalate Example 28 Lameproofing of a polyamide parts of a commercially available nylon 6 are dissolved in 85 parts of trifluoroethanol .. This solution is mixed with the corresponding amount of flair.eproofing agent and homogeneously stirred. Films are prepared in a manner analogous to that described in Example 27 for polyethylene terephtha late and the LOI values are determined. The following Table shows how the LOI value is increased by addition of the flameproof-ing agents according to the invention as compared with nylon 6 without flameproofing agent. * based on nylon 6 Example 29 Flameproofing of polyacrylonitrile 201 parts of commercially available polyacrylonitrile are dissolved in 80 parts of dimethyl formamide. This solution is mixed with the corresponding' amount of flameproofing agent and stirred to homogeneity. Sheetings are prepared in a mirft-ner analogous to that described in Example 27 for polyethy- lene terephthalate and the LOI values are determined. The following Table shows how the LOI vlaue is increased by addition of the flameproofing agents according to the invention as compared with polyacrylonitrile without flameproofing agent.

Example 30 2-0x0-2- tetrahydrofuryloxy-3 ,3 , 5- rime h 1- 5-di- (tetrahydro-furfur l)-phosphono- 1 , 2-oxaphospholane As described in Example 1 , a mixture of 37 . 6 g of di-tetrahy-drofurfuryl phosphite and 4. 9 g of mesityl oxide in 80 ml of benzene is reacted by heating in the presence of 1.3 g of sodium over the course of 1 hour. The reaction is vigorously exothermic. The sodium is neutralised by addition of 3.4 g of glacial acetic acid, then inorganic 'salt is extracted from the mixture with 2 times 20 ml of water. The benzene is removed in a rotary evaporator leaving as residue 32.6 g of crude product which still contains di- tetrahydrofurfury1 phosphite. Distillation of 4.3 g of the crude product in a bulb tube oven in a high vacuum yields the reaction product at an oven temperature betweeti 185 °C and 230°C and a pressure of 0.01 mm Hg.

Yield: 2.07 Analysis: C21H3gP209 (M = 496.48) calc: C 50.8 H 7.7 P 12.5 found: C 49.5 H 7.7 P 12.6 Although the mass spectrum does not show the molecular peak at m/e 496 it does show instead the M+H peak at m/e 497.

Fragments characteristic of this compound occur at m/e 426 (M+-C4H60) and 413 (M+-C5H70) .

Example 31 Flameproofing of epoxy resins A rigid foam based on epoxide resin was manufactured from the following constitutents: resin: 105 parts of epoxide resin based on bisphenol A with an epoxide equivalent weight of 190 s 45 parts of epoxide resin based on bisphenol A with an epoxide equivalent weight of 400 2 parts of foam stabiliser Si 3193 (Messrs. Rhodia; a glycol-silicone copolymer) 5 parts of pentane 5 parts of trichloromonofluoromethane hardener: 7 parts of dieth lene triamine 7 parts of di- (aminomethy1) -eye lohexylmethane 1 part of bisphenol A 12 parts of l,6-diamino-2 ,4,4- trimeth lhexane 3 parts of phenol Resin and hardener are thoroughly mixed at room temperature and poured into a wooden mould. The foam is removed after 1 2 hour; it has a density of 0.1 g/cm .

Specimen rods measuring 10 x 15 x 120 mm are cut from the rigid foam and subjected to a flammability test according to ASTM 635. In this test, the rod is hung at an angle of 45° and ignited at its bottom end with a gas flame. The combustion time up to the 10 cm mark is measured and the combustion speed is calculated therefrom. The rigid epoxide foam has a combustion speed of 2 sec. /cm.

An epoxide foam of the same composition is manufactured except that 25 parts of 2-oxo-2-ethoxy-3 , 3 , 5- trimethy1-5-diethy1-phosphono- 1 ,2-oxaphospholane are additionally mixed with the resin. The test of this foam' by ASTM 635 shows that the resin is .self-extinguishing: the measurement mark is not reached.

Claims (22)

CIAIMS:

1. Compounds of the formula I wherein each of R, , R and Q independently represents an 1 2 J alkyl, alkenyl, haloalkyl, alkoxyalkyl, cycloalkyl or a tetrahydrofurfuryl radical, each of R^, R^ and Rg independently represents hydrogen or alkyl or a phenyl radical optionally substituted with alkyl, alkoxy or halogen or is a furyl radical and ? represents alkyl.

2. Compounds according to claim 1, wherein each of R^, and R^ independently represents alkyl with 1 to 18 carbon atoms, haloalkyl or alkoxyalkyl having not more than 18 carbon atoms, alkenyl with 3 to 18 carbon atoms, or R^ represents' a tetrahydrofurfuryl radical, R^ represents hydrogen or methyl, R,- represents hydrogen, alkyl with 1 to 8 carbon atoms, phenyl optionally substituted by halogen, alkyl or alkoxy groups with 1 to 4 carbon atoms or represents furyl, R, represents hydrogen, methyl or phenyl and R_ b 7 represents alkyl with 1 to 8 carbon atoms. 45509/2

3. Compounds of the formula I, wherein each of R-^ and R2 indpendently represents an alkyl, alkenyl or cycloalkyl radical, R3 is the same as either or R^, each of R. , Rc and Rc independently represents hydrog* 2 4 b D alkyl or phenyl radical and R? represents alkyl. .

4. Compounds according to claim 3, wherein each of and R2 independently represents alkyl with 1 to 18 carbon atoms, haloalkyl or alkoxyalkyl having not more than 18 carbon atoms, alkenyl with 3 to 18 carbon atoms, cycloalkyl with 5 to 8 carbon atoms, R^ is the same as ^ or R^r ^ represents hydrogen or methyl, R,. represents hydrogen, alkyl with 1 to 8 carbon ato'ms, phenyl optionally substituted by halogen, or represents furyl, ^ represents hydrogen, methyl or phenyl and R7 represents alkyl with 1 to 8 carbon atoms. 45509/2

5. Compounds according to claim 3, wherein R , R2 an R3 are identical and represent linear or branched alkyl radicals with 1 to 8 carbon atoms, alkox alk l with 3 to 6 ca bon atoms, chloroethyl, broraoethyl, alkenyl with 3 or 4 car bon atoms,or cyclohexyl, R4 represents hydrogen or methyl, R¾ represents hydrogen, methyl, ethyl, phenyl, chlorine and/or bromine substituted phenyl or tolyl, xylyl, anisyl or furyl, Rg represents hydrogen and R7 represents methyl or ethyl.

6. A process for the manufacture of compounds of the formula I R1 to R7 have the same meanings as in Claim 1 which process comprises reacting an α,β-unsaturated ketone of the' formula II R„ R 0 4\ I 6 „ (II) C=C—C—R„ / R5 with at least 2 moles of a phosphite of the formula III in the presence of a base, with or without- the addition of a solvent.

7. A process according to claims 6. which comprises reacting a compound of the formula II, wherein represents hydrogen or methyl, represents hydrogen, alkyl with 1 to 8 carbon atoms, phenyl optionally substituted by halogen, or represents furyl, R^ represents hydrogen, methyl or phenyl and represents alkyl with 1 to 8 carbon atoms with a compound of the formula III, wherein each of R^ and 2 independently represents alkyl with 1 to 18 carbon atoms, alkyl with altogether 1 to 18 carbon atoms which is substituted by halogen and/or alkoxy, alkenyl with 3 to 18 carbon atoms, or cycloalkyl with 5 to 8 carbon atoms.

8. A process according to claim 6, which comprises reacting a compound of the formula II, wherein represents hydrogen or methyl, R5 represents hydrogen, methyl, ethyl, phenyl, chlorine or bromine substituted phenyl } tolyl , xylyl, anisyl or furyl, represents hydrogen and represents methyl, ethyl or phenyl with a compound- of the formula III, wherein R^ and R2 are identical and represent alkyl with 1 to 8 carbon atoms, alkoxyalkyl . with 3 to 6 carbon atoms, chloroethyl, bromoethyl, alkenyl with 3 or 4 carbon atoms, or cyclohexyl.

9. A process for the manufacture of compounds of the formula I, wherein R^ to have the same meanings as in Claim 1 which process comprises reacting a compound of the formula IV 0 R, Rr .0 I 4 Γ it (IV) (R5,0) 2P~0I—CH—0—l 7 Rr with at least 1 mole of a phosphite of the formula III in the presence of a base, with or without the addition of a solvent,

10. A process according to claim 6, which comprises the use of 2.5 to 3.5 moles of. a compound of the formula III for each mole of a compound of the formula II.

11. A process according to claims 6 to 9, which comprises the use of an alkali metal, an alkali metal alkoxide or an alkaline earth metal alkoxide, an alkali metal amide or a metal hydride, as base.

12. A process according to claim 11, which comprises the use of metallic sodium or potassium, sodium methoxide, potassium tert. butoxide, lithium amide, sodium amide or calcium hydride as base.

13. A process according to claims 6 to 9, which comprises the use of a hydrocarbon, an alcohol or an ether as ,> solvent.

14. A process according to claim 13, which comprises the use of benzene, toluene, xylene, ligroin, hexane or heptane as solvent.

15. A process according to claims 6 to 9, which comprises carrying out the reaction at elevated temperature.

16. A method of flameproofing thermoplastic polymers, polyurethanes , cellulose and derivatives thereof which comprises adding to the polymer at least one compound of the formula I according to claim 3.

17. A method of flameproofing thermoplastic polymers, polyurethanes, epoxy resins, cellulose or cellulose derivatives, which comprises adding to the polymer at least one compound of the formula I according to claim 1.

18. A method according to claims 16 and 17, which comprises adding the flameproofing agent during the manufacture of the polymers.

19. A method according to claim 18, which comprises adding the flameproof ng agent during the manufacture of poly- urethana foams made from polyisocyana tes and polyhydroxy coti- pounds.

20. Flame resistant thermoplas ic polymers, polyurethanes cellulose or cellulose derivatives, which contain at least one compound according to claim 3.

21. Flame resistant polyurethane foams according to claim 20.

22. A method of flameproofing epoxy resins, which comprises adding to their components, before or during the manufacture of the epoxy resins, a compound of the formula I ac¬ 2^ Flame resistant thermoplastic polymers, polyure- thanes, epoxy resins, cellulose or cellulose derivatives, which contain at least one compound according to claim 1.