DE2357678A1 - Alkenephosphonic (phosphinic) acid chlorides prepn. - by dehydrochlorination of chloroalkane-phosphon(in)ic acid chlorides - Google Patents

Abstract

Acid chlorides of formula (I): (where R1 is Cl, 1-18C alkyl (pref. CH3 or C2H5), or phenyl or benzyl opt. substd. in the aromatic ring, and R2 is H or 1-10C alkyl (pref. CH3)), e.g. vinylphosphoric acid dichloride, are prepd. by catalytic dehydrochlorination of cpds. of formula using as catalyst a cpd. which (a) contains at least one 3- to 5-valent N-atom or one 5-valent p-atom, 1-4 valences of the N-atom and is not 3 valences of the p-atom being linked to opt. substd is not >20C organic residues, 2 of these valences opt. forming a double bond, or (b) is a fully amidated mono- to tribasic organic or inorganic acid of 3- to 5-valent phosphorus the N-atoms of which are alkylated by opt. subst. is not >20C aliphatic residues and the opt. subst. organic residue of which is is not > 20C. Suitable catalysts include trimethylamine, pyridine, dimethylformamide, tetramethylammonium chloride, tetraethylphosphonium chloride and trimethylphosphine oxide. (I) are useful as intermediates for flameproofing agents, plant protection agents, detergents, flotation agents and plastics.

Description

Process for the production of alkene phosphonic acid chlorides and alkene phosphinic acid chlorides

It is known that vinylphosphonic acid dichloride and vinylphosphinic acid chloride can be used by splitting off hydrogen chloride from the corresponding 2-chloroethane phosphonic or phosphinic acid chlorides prepared with the help of stoichiometric amounts of tertiary amines in inert solvents (Gefter and coworkers, Z. obsc. chim. 31 (1961) No. 3, pages 955-958; Schweizerisches U.S. Patent No. 391,699; DOS 1,158,509).

These reactions can be shown schematically as follows:

ClCH ₂ CH ₂ PCl ₂ + NR "

\ _R 1M

► CH ₀ = CHPCl ₀ + R "-N • HCl

^R '\

P-Cl + R "-N CH _O ⁼ CH ο R"

HCl

The amounts of amine required for the cleavage, the

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separation of the amine hydrochloride, the recovery of the free Amine and distilling off the solvent used make these processes uneconomical and cumbersome. Furthermore, the Swiss patent specification No. 391.699 describes the elimination of hydrogen chloride from 2-chloropropane phosphonic acid dichloride by heating to 200 ° C with formation of propene phosphonic acid dichloride. The required response time 15 hours is uneconomical. In addition, these lead long reaction time and the high reaction temperature in the production of more sensitive alkene phosphonic acid chlorides, such as Yinylphosphonic acid dichloride, to substance loss due to strong resinification and occasionally also to deflagration.

DOS 1.568.945 describes a significant reduction in the reaction time by heating 2-chloroethane phosphonic acid dichloride in the presence of triphenylphosphine as a catalyst.

Tripheny! Phosphine, however, is a difficult compound to make.

The invention now relates to a process for the catalytic production of acid chlorides containing vinyl groups Phosphorus of the general formula (I)

* ° ^R 1

C = CH-P ^ (I)

in which R is chlorine, an alkyl group with 1-18, preferably 1-4, in particular 1 or 2 carbon atoms, or a phenyl or benzyl group optionally substituted on the aromatic ring, and R _{0 is} an alkyl group with 1-10, preferably 1 -4 C atoms, preferably methyl, or hydrogen, by catalytic splitting off of hydrogen chloride from compounds of the general formula (II)

R ₉ H 0 R ₁
A. I Il / !

V-c-p ^ (H)

H Cl H ^N C1 ... 3

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in the R- and R "have the above meaning, which is characterized is that such compounds are used as catalysts

contain at least one 3- to 5-bond nitrogen or a 5-bond phosphorus atom, which in the case of nitrogen with 1-4 valences, in the case of phosphorus with at least 3 valences to organic, optionally substituted radicals with up to 20 carbon atoms is bonded, 2 of these valences being able to form a double bond, or 1- to 3-basic organic or inorganic, fully amidated acids of the 3- to 5-valent

-Ip-phosphorus, the N atoms of which are optionally substituted by aliphatic radicals with up to 20 carbon atoms and their optionally substituted organic radicals up to 20 May contain carbon atoms.

The inventively catalytically active nitrogen and Phosphorus compounds can be shown schematically by the general formulas (III), (IV), (V) and (VI)

^R 3
(HD

R ₁ = XR ₂

(IV)

Et R,

(V)

r ~? ^R.

Z (VI)

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are reproduced, in which X is nitrogen or in formulas V and VI also phosphorus, Y is an inorganic or organic acid residue, R _{1 is} an organic residue with 1-20 C atoms, R ₂ and R _{3 are} each an organic residue with 1-20 C- Atoms or H, v / if X = N,

where for X = N one of the ligands R-, R, R "is the remainder of a

1 j4 O

optionally polybasic carboxylic acid or the remainder of an inorganic or organic acid of the trivalent or pentavalent nature Phosphorus or its optionally alkylated amides,

R _{4 is} an organic radical with 1-20 carbon atoms, or H, if X = N and R _{1 and R 3 are} each an organic radical, Z is oxygen or, if X = P, sulfur or 2 halogen atoms or NR ^ »Where R_ = Ή or an organic radical with 1 - 20 C atoms can mean.

Accordingly, an N or P atom can stand for X and an inorganic or organic acid radical for Y, for example a halogen ion, an SO ₄ ion, a methyl sulfate ion or the ion of an organic sulfonic acid. ^!

R-, Hg » ^R 3 * ^R 4 ^{and R} 5 can be identical or different organic radicals, for example straight-chain or branched alkyl groups with 1-2O carbon atoms, preferably 1-12, in particular 1-4 carbon atoms, alkenyl groups with 2 - 20, preferably 2-12, especially 2-4 carbon atoms, cycloalkyl or alkenyl groups with 4-8, preferably 4-6 carbon atoms, aryl or aralkyl groups with 6-20, preferably 6-12 carbon atoms or acyl groups with 1-4, preferably 1 or 2 carbon atoms, where all radicals R ₁ to R ^ in turn, preferably by halogen, in particular chlorine and / or bromine or alkoxy radicals with 1-4 carbon atoms, preferably 1-2 C atoms or a dialkylamino group with alkyl groups of 1-4 C atoms, preferably monosubstituted, can be.

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Two of the radicals R ~~ to R can be members of a heteroeyclic Ring of aromatic or cycloaliphatic nature, the further heteroatoms, e.g. nitrogen, oxygen or Sulfur.

If X = nitrogen, Rg and / or R ₃ and, if R _{1 and R 3 are} organic radicals, R can also mean hydrogen. .

Z can represent oxygen or, if X is phosphorus, also represent sulfur, two halogen atoms, preferably 2 chlorine atoms, or represent the group NR ^, where R ₁ . = H or an organic radical with 1 - 20 C atoms can be.

If. X is nitrogen, one of the radicals R ^ to R _{3 can be} an acid amide radical or acid diamide radical of an organic acid of trivalent or pentavalent phosphorus, the N atoms of which have alkyl groups with 1-18 carbon atoms, preferably 1-4 carbon atoms -At, omen, can be substituted. Compounds in which the amide group (s) are mono-, in particular disubstituted, in the manner described are preferred.

The compounds catalytically active according to the invention can also contain several identical or different elements of the meaning X. The molecular weight of the catalyst used is preferably up to 500, in particular up to 200.

As catalysts according to the invention, for example, can be used will:

Amines such as tr! Diethylamine, triethylamine, tripropylamine, tributylarain, Dimethylethylamine, diethylbutylaiain, dimethyldodecylamine, N-dimethy! Aniline, 4-methyl-N-dimethy! Aniline, N-diethy! Aniline,

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-Q-

N, N ^f -tramethyl-p ~ phenylenedia; min, triphenylamine, diethylamine, N-butylamine.

Heterocyclic nitrogen compounds such as pyridine, quinoline, Isoquinoline and its alkyl or dialkyl, preferably methyl or dimethyl derivatives, imidazole, N-vinylimidazole, benzimidazole, Benzthiazole, benzotriazole, 2-amino-τ6-ethoxybenzthiazole, 2-hydroxy-5,7-dimethylpyrazolo (l, 5, a) pyrimidine, N ~ methyl! Pyrrolidine, N-Xthy! Piperidine, Pyrrolidinocyclohexene, triazole, piperidine, as well as their oxides, e.g. pyridine oxide.

Acid araids, e.g. dimethylformamide, diethylformainide, diethylpropionaid, N-Dimethy 1 benzamide, Ν, Ν'-Tetramethylterephthalic acid diamide, Hexamethylphosphorsäuretriamid, Äthanphosphonsäure-bisdiäthylamid, Methanbutanphosphinigsäuredimethylamid, Di-Äthylphosphinigsäureisobutylamid, or ureas such as tetraraethylurea and NjiTjN'-methyl-N-phenylurea.

Quaternary ammonium salts, e.g. tetramethylammonium chloride or bromide, trimethylbenzylammoniumchloride, triethylbenzylammonium chloride or -broraid, trimethylchloromethylammonium chloride.

Quaternary phosphonium salts, e.g. tetraethylphosphonium chloride, trimethylbenzylphosphonium chloride, triphenylethylphosphonium-2,4-diaminobenzene sulfonate.

Organic compounds of 5-bond phosphorus, e.g. trimethylphosphine oxide, Tributylphosphine oxide, trihexylphosphine oxide, triphenylphosphine oxide, Dimethylphenylphosphine oxide, dimethylchloromethylphosphine oxide, Dimethylhexylphosphine oxide, dimethyldodecyl phosphine oxide, DimethyleikosyIphosphinoxid, Dimethylpyrrolidirt-1-MethyIphosphinoxid, Dimethylphenylphosphine sulfide, dimethyldodecylphosphine sulfide, 2-dimethylphosphinylpropionic acid methyl ester, 1-Methylphospholen ~ 3, l-Ethyl-S-methylphospholen-S,

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2-FluorosulfonyläthyIdimethylphosphinoxid, N-2-Dimethylphosphinyläthy1-N-Methylacetamid, N-2-dimethylphosphinylethylethylamine, Triphenylphosphine dichloride, dimethylchloromethyldichlorophosphorane, Triphenylphosphinimine, triphenyl-n-2-hydroxyethylphosphinimine.

Triethylarain and triethylamine hydrochloride are particularly preferred among these compounds. Preference is also given to the other, including the mixed, tri (C ₀ -C.) - alky! Amines, the trialky! Phosphine oxides, in particular the trimethylphosphine oxide, and their HCl adducts, and also mixtures of these compounds.

The catalysts of the invention are used in amounts of 0.01-5% by weight or more, based on the compound of the formula (II) used, preferably in amounts of 0.05-2% by weight, used. They can be used as such or in the form of their salts, preferably their hydrochlorides.

The process according to the invention is generally simpler Manner carried out in such a way that a compound of the formula (II) mixed with one of the mentioned catalysts, the reaction mixture is heated and at temperatures of about 150 - 200 C, preferably 160-190 ° C., hydrogen chloride in a manner known per se and the corresponding vinyl compound of the formula (I) is distilled off. When performing the distillation under reduced Pressure decreases the transition temperature accordingly and the reaction proceeds more rapidly. A special economic one The advantage of the claimed process consists in the possibility that instead of pure 2-chloroalkanephosphonic or phosphinic acid chlorides emanate from such crude products can, which can be obtained by phosgenation of 2-chloroalkane-phosphon- or phosphinic esters (e.g. according to DOS 2.132.962; DOS 2.215.314 .; DOS 2.129.583; P 22 25 545.4), those to be used according to the invention for the splitting off of HCl

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May already contain catalysts from their manufacture, so that - especially in the case of the phosphonic acid dichlorides - further catalyst additives can be unnecessary.

A particularly preferred variant of the method therefore allows the four methods mentioned above, for example obtained products, which the catalysts of the invention already added in the previous phosgene fermentation reaction wox'den are, without intermediate classification and without change of the reaction vessel in the manner of a so-called one-pot process to convert directly to vinyl compounds of the formula (I), as the following examples show.

The alkene phosphonic and phosphonic acid chlorides obtained by the process of the present invention are valuable Intermediate products for flame retardants, pesticides, Detergents, flotation aids and plastics.

The invention is illustrated by the following examples:

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2357S78

Example 1:

137 g of phosphorus tricloride are reacted with 135 g of ethylene oxide to give tri (chloroethyl) phosphite. The reaction product is rearranged at 140-145 ° C. to give chloroethane phosphonic acid di (chloroethyl) ester and converted into chloroethane phosphonic acid dichloride using the method of DOS 2.132.962 using phosgene in the presence of 2 g of diethylamine as a catalyst. The reaction mixture, which already contains triethylamine as a catalyst, is then heated to a bottom temperature of around 200-220 ° C. With evolution of hydrogen chloride, 143 g of a colorless liquid distilled over the course of 3 hours at a head temperature of 170 ° - 180 ° C. and normal pressure, which, according to gas chromatographic analysis, 90% vinylphosphonic acid dichloride (89% of theory based on PCl ₃ ) and 9 % 2-chloroethane phosphonic acid dichloride (6% of theory) and from which 128 g of vinylphosphonic acid dichloride are obtained by fractionation under reduced pressure. The 2-chloroethane phosphonic acid dichloride remaining as a residue during this fractionation can be subjected to the cleavage again. If this cleavage is carried out under reduced pressure of 400-500 Torr, the reaction time can be shortened to 1.5 hours with the same yield and lower distillation temperature.

Including the recovered chloroethane phosphonic acid dichloride the yield of vinylphosphonic acid dichloride is 93.5% of theory, based on the PCI used «·

Example 2:

260 g of phosphorus trichloride are added analogously to example (1) with 255 g Ethylene oxide reacted, the adduct rearranged and 500 g raw 2-Chloräthanphosphonsäure-di-chloroethyl ester obtained, which is now with phosgene with the addition of 5 g of dimethylformamide as a catalyst

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2357673

is converted into 2-chloroethane phosphonic acid dichloride. The reaction mixture already containing dimethylformamide as a catalyst is then distilled at a bottom temperature of approx. 200 ° C. and a pressure of approx. 400 torr. Within 2 hours, 249 g of a distillate is obtained which contains 90% vinylphosphionic acid dichloride (82% of theory) and 9 % 2-chloroethanephosphionic acid dichloride (8 % of theory). Including the recovered 2-chloroethane phosphonic acid dichloride, the yield of vinyl phosphonic acid dichloride is 91% of theory, based on the phosphorus trichloride used.

Example 3:

55 g of phosphorus trichloride are reacted analogously to Example - (I) with 65 g of propylene oxide, and the tris (2-chloropropyl) phosphite obtained is rearranged by heating to 170 ° C. for 5 hours. The obtained 2-C-propane phosphonic acid di (2-chloropropyl) ester is converted into the dichloride with phosgene after the addition of 1 g of pyridine. The crude product thus obtained, which already contains pyridine as a catalyst, is now distilled at a sump temperature of about 200 C and a pressure of about 400 Torr. Within 50 minutes to obtain 47 g of boiling Propylenphosphonsäuredichlorid _g 77 ° - 79 ° C, corresponding to 73% of theory, based on phosphorus trichloride.

Example 4;

To 77O g of methyldicfelorphosphine in 3.5 1 of chlorine benzene are under Stirring and cooling at 20 ° - 25 ° C initiated in the course of 3 hours 650 g of ethylene oxide. After stirring for one hour at 20-30 ° C the resulting solution is heated to 140 ° C. under nitrogen over the course of 2 hours and kept at 130 ° -140 ° C. for 3 hours. To Distilling off the chlorobenzene under slightly reduced pressure, 1356 g of almost colorless oil remain, which without any further

... 11

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Cleaning in a cylindrical gas supply vessel with a bottom frit after addition of 5 g of triphenylphosphine oxide at 130-140 ° C., phosgene is fumigated until after 3 hours with the exhaust gases there is no Dichloroethane distilled off more. 836 g of crude methane-2-chloroethylphosphinic acid chloride remain as a brownish oil, which already contains triphenylphosphine oxide as a catalyst and now in a distillation apparatus at a pressure of 400 - 500 Torr heated to 180 ° - 200 C sump temperature is, a small amount of colorless oil distilled over with the resulting hydrogen chloride. After heating for three hours the entire reaction mixture is distilled over by lowering the pressure. Fractional distillation gives from it 585 g of methanevinylphosphinic acid chloride and 70 g of higher-boiling components, the 85% methane-2-chloroethylphosphinic acid chloride contain. Including the recovered methane-2-chloroethylphosphinic acid chloride, the yield is based on methanevinylphosphinic acid chloride 75% of theory on methyldichlorophosphine used.

Example 5: _ ·

59 g of methyldichlorophosphine in 120 g of o-diehlobenzene are used with stirring and cooling at 30 ° C. in 1 hour with 58 g of propylene oxide offset. The reaction mixture is heated to 170 ° C. over the course of half an hour and at this temperature for 2 hours held. After the solvent has been distilled off under reduced pressure, the residue is removed with the addition of Ig Triethylamine reacted with phosgene at about 150.degree. The crude mixture obtained, which already contains the catalyst triethylamine, is subjected to cleavage analogously to example (4). They are made by fractional distillation under reduced pressure

58 g Methanpropenylphosphinsäürechlorid of bp ₂₇ 99 C obtained, corresponding to a yield of 84 % of theory, based on the methyldichlorophosphine used.

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_ IO

Example 6:

320 g of crude, 85% strength benzene-2-chloroethane phosphinic acid 2-chloroethyl ester, which was obtained analogously to the previous examples by addition of ethylene oxide onto benzene dichlorophosphine and thermal rearrangement of the addition product, are mixed with phosgene after adding 4 g of pyridine at 135-145 ° C. implemented. The reaction product, which already contains the catalyst pyridine, is distilled at a bath temperature of 200 ° C. under a pressure of 20 torr, with 60 g of resinous residue remaining. Fractional distillation of the crude distillate yields 172 g of benzene vinylphosphinic acid chloride with a boiling point of _no

Oo »

94-95 ° C.

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Claims (4)

HOE 73 / F 354 - 13 - PATENT CLAIMS: Process for the catalytic production of vinyl groups containing acid chlorides of phosphorus of the general formula (I), ^R 2 _X \\ / \ - * C = CH-P ^ - (I) in which R is chlorine, an alkyl group with 1-18, preferably 1-4, especially 1 or 2 carbon atoms, or an optionally substituted phenyl or benzyl group on the aromatic ring, and R _{2 is} an alkyl group with 1-10, preferably 1 -4 C atoms, preferably methyl, or hydrogen, by catalytic splitting off of hydrogen chloride from compounds of the general formula (II), R ₀ HOR H - C -C-P ^ (II), H ^ in which R ₁ and R "have the above meaning, characterized in that the catalysts used are compounds which contain at least one 3- to 5-bond nitrogen or a 5-bond phosphorus atom, which in the case of nitrogen with 1-4 valences, in the case of phosphorus with at least. 3 valences to organic, optionally substituted radicals is bonded with up to 20 carbon atoms, 2 of these valences being able to form a double bond, or 1- to 3-basic organic or inorganic fully amidated ... 14- 509822/1018, 2357878 Acids of 3- to 5-valent phosphorus, their N-atoms through optionally substituted aliphatic ^ radicals with up to 20 carbon atoms be alkylated and their optionally substituted organic residues can contain up to 20 carbon atoms. 2) Process according to claim 1, characterized in that the catalytic elimination of hydrogen chloride is carried out at normal pressure or under reduced pressure. 3) Process according to claims 1 and 2, characterized in that 0.01 to 5 wt .-%, preferably 0.05 to 2 Ge \ v .-% Catalyst, based on the starting compound of the formula (II), used. 4) Process according to Claims 1 to 3, characterized in that the catalyst is already added to the phosgene mixture for the preparation of the starting materials of the formula (II) is added. 509822/1018