CH616431A5 - Process for the preparation of novel unsaturated phosphorus-containing carboxylic acid derivatives - Google Patents

Description

616431

2nd

PATENT CLAIMS 1. Process for the preparation of carboxylic acid derivatives of the formula I

P - Y - 0

0 II

C.

- C = CH

2 (I)

Filo in which Ri and R2 stand for alkyl radicals with a total of up to 8 C atoms, Ra for a hydrogen atom or a methyl group, X for an oxygen or sulfur atom, Y for an alkylene chain with up to 6 C atoms, characterized in that alcohols of the formula II

Phosphine oxides, which are characterized by good flame-retardant properties. They are generally prepared from dimethylchlorophosphine, which is obtained in the technical process of reacting methyl chloride with phosphorus at about 350 ° C. together with methyldichlorophosphine (DAS 1 568 928). For the methyldichlorophosphine, however, a similar use for flame protection, as described above for the dimethylchlorophosphine, has not hitherto become known, which considerably impairs the economics of the use of the dimethylchlorophosphine mentioned above.

The invention therefore relates to a process for the preparation of new phosphorus-containing carboxylic acid derivatives of the formula (I)

15

R

X

i \ JI

P - Y - OH

(II)

20th

H-. * O. . -Kji Ii

JU'-Y-O-C-C CTI.

3rd

(I)

R20

with compounds of formula III

Z - CO - C = CH,

I '

(III)

in which R, and R, for alkyl radicals with a total of up to eight C atoms, preferably lower alkyl radicals each with 25 I to 4 C atoms, R3 for a hydrogen atom or a methyl group, X for an oxygen or sulfur atom, preferably oxygen, Y represents an alkylene chain with up to 6, preferably 1 to 3, carbon atoms.

The process according to the invention is characterized in that alcohols of the formula (II)

in which Z represents a halogen atom, in the presence of an inert solvent. '

2. The method according to claim 1, characterized in that one carries out the reaction in the presence of a polymerization inhibitor for the acrylic group or methacrylic group.

3. The method according to claim 1, characterized in that one carries out the reaction with the addition of hydrogen halide-binding compounds.

4. The method according to claim 1, characterized in that compounds of formula II are used in which R, and R., mean lower alkyl radicals each having 1 to 4 carbon atoms.

5. The method according to claim 1, characterized in that one uses compounds of formula II in which X is oxygen.

6. The method according to claim 1, characterized in that compounds of the formula II are used in which Y is an alkylene chain having 1 to 3 carbon atoms.

7. The method according to claim 1, characterized in that compounds of formula III are used in which Z is chlorine.

Unsaturated phosphorus-containing carboxylic acid derivatives of the formula

CHL 0 O

3 \ ll. x »

P- (CH0) OC-OCII ,, 2 n °

CH,

L

*1

in which R, represents a hydrogen atom or a methyl group and n denotes the numbers 1, 2 or 3 are already known (DOS 2 052 569). Derivatives are more tertiary

U,

35

"P-Y-OII

(II)

it0o in which R "R2, X and Y have the meanings given above, with compounds of the formula (III)

• z-co-c -cii-

aii)

ii.-,

in which Z represents a halogen atom, preferably chlorine and R; s has the meaning given above, in the presence of an inert solvent. 50 The acylation of alcohols of the formula (II) according to the invention with acrylic or methacrylic acid halide of the formula (III) can be carried out in a manner known per se, preferably in the presence of a hydrogen-halogen-binding compound, for example a tertiary amine such as tri-55 ethylamine or pyridine, at temperatures from -30 ° C. to + 100 ° C., preferably +20 "to + 70 ° C. The compound which binds hydrogen halide is generally used in equimolar amounts, based on the acid halide of the formula (III), or moreover in a minor amount Excess used up to about 10%.

It is also preferred to use one of the polymerization inhibitors known for acrylic acid derivatives, such as e.g. Phenothiazine, hydroquinone, hydroquinone monomethyl ether and / or metal salt inhibitors. The amount of inhibitor is expediently chosen within the usual limits, for example between 0.01 and 1% by weight, based on the compound of the formula (III). The presence of effective polymerization inhibitors is also, for example

3rd

616431

important in the processing of the crude reaction mixture, if appropriate by distillation.

The starting components of the formulas (II) and (III) are generally used in approximately equimolar amounts, it also being possible to use the acid halide of the formula (III) in a slight excess of up to approximately 10%. The reaction of the reactants is expediently carried out with the exclusion of water.

The reaction is expediently carried out in such a way that the alcohol of the formula (II), together with the tertiary amine which may be used, is initially introduced in the inert solvent at room temperature and the acid chloride of the formula (III) is added dropwise, with thorough mixing of the batch, e.g. with a stirrer.

The reaction temperature is not critical and can change in the course of the reaction due to the heat of reaction released within the above-mentioned temperature range, i.e. Increase to about 100 ° C, which can be advantageous for the course of the reaction. The starting components of formula (II) are easily accessible compounds. For example, hydroxymethyl-alkylphosphinic esters are obtained by addition of paraformal dehyde to alkylphosphonous esters by the method of DOS 2 226 406. 2-Hydroxyethylalkylphosphinic esters can be obtained in good yields from the 2-acetoxyethyIaIkyI-phosphinic esters by the method of DOS 2 235 852, and in 3-hydroxypropyl-alkylphosphonic acid esters can also be obtained analogously.

Typical phosphorus-containing carboxylic acid derivatives of the formula (I) prepared according to the invention are, for example: The acrylic acid and methacrylic acid esters of methyl, methyl, propyl, isobutyl, ethyl hydroxymethylphosphinate, methyl, ethyl, -pro-pyi-, -isobutyl ester, isobutyl ester, methyl-2-hydroxyethylphosphinate, isobutyl methyl, 2-hydroxyethylthiophosphinate, propyl propyl-2-hydroxyethylphosphate, methyl- (2-hydroxy-2-methyl-ethyl) -phosphinate, ethyl, propyl, n-butyl, isobutyl, pentyl ester, methvl - 3-hydroxypropylphosphinic acid isobutyl ester, butyl 3-hy-hydroxypropylphosphinic acid isopropyl ester.

Inert solvents which can be used are, for example, the solvents customarily used for esterifications and / or transesterifications, such as benzene, toluene, xylene, chlorobenzene, carbon tetrachloride, chloroform, diisopropyl ether, acetonitrile or mixtures of such compounds. The amount of the inert solvent to be used is not critical and suitably depends on the stirrability of the reaction mixture after the reaction has ended, in which the halogen-water-binding compound which may also be used is generally crystalline as the hydrohalide. The inert solvent is therefore generally used in about 1 to 10 times, preferably in 2 to 5 times, the amount by weight, based on the alcohol of the formula (II). The preferred inert solvent is xylene.

Due to their unsaturated carbon-carbon bonds, the new carboxylic acid derivatives of the formula (I) are suitable as monomers or comonomers for the preparation of polymers. For example, copolymerization with monomers such as acrylic acid derivatives, styrene or vinyl compounds gives flame-retardant polymers with improved dyeability and antistatic properties. For example, copolymers consisting of acrylonitrile, vinyl chloride, vinyl bromide and / or vinyl chloride and compounds of the formula (I) have a surprisingly high flame resistance. In addition, fibers and fibers from the above show

Copolymers have an unexpectedly high thermal stability, i.e. they are much less prone to yellowing under thermal loads, compared to the relevant state of the art.

5 By transesterification of the phosphinate ester groups OR2 contained in the polymers - preferably for Ro = alkyl with 1 to 4 carbon atoms, especially methyl or ethyl - with glycols such as ethylene glycol, diethylene glycol, propylene glycol or higher glycols, the polymers obtained can also be crosslinked will. With methyl dichlorophosphine as the starting material, the phosphinic esters of the formula (I) according to the invention are far more readily accessible than the analogous tertiary phosphine oxides, for the preparation of which dimethyl chlorophosphine is required as the starting material. In contrast to dimethylchlorophosphine, however, methyldichlorophosphine is a technically easily accessible starting material which, for example, can be obtained as the exclusive reaction product in a known manner by reacting methane with PCLa at 600 ° C.

example 1

252 g (1.52 mol) of isobutyl methylhydroxymethylphosphinate, 153 g (1.52 mol) of triethylamine and 1 g of pheno-25 thiazine are dissolved in toluene and, with stirring and gentle cooling at 20 ° to 30 ° C., 137.5 g (1.52 mol) acrylic acid chloride dropped. The mixture is stirred for 15 hours. After another hour, the tri-ethylamine hydrochloride which has precipitated is filtered off with suction. After the solvent has been distilled off and the polymerization inhibitors have been added, the filtrate is distilled under reduced pressure.

185 g are obtained

35

CH "O

il

P-CII

(CIl3) 2CIK: iI2

ö

r, -o-c-cii »cn,, II x

ü

Bp: 95-98 ° C / 0.1 Torr.

40 This corresponds to a yield of 55.5% of theory. Analysis:

found: C 49.3% H 7.7% P 14.0%

calculated: C 49.1% H 7.72% P 14.1%

45 Example 2

500 g (2.78 mol) of isobutyl methyl-2-hydroxyethylphosphinate, 281 g (2.78 mol) of triethylamine and 1.5 g of phenothiazine are dissolved in 1.67 l of toluene and 252 g (2.1 78 mol) of 50 drops of acrylic acid chloride. The temperature rises to 50 ° C. After the dropping has ended, the mixture is stirred for a further 15 hours. The mixture is then cooled to + 10 ° C. and the triethylamine hydrochloride which has precipitated is filtered off with suction Vacuum distilled.

485 g are obtained

CH.

60

(cir3) 2chch., o

0 II

P CH ..- CH ,. -0 - C -CttsCH O

Kp .: 145 ° C / 2 Torr.

65 This corresponds to a yield of 75% of theory. Analysis:

gel '.: C 51.4% H 8.10% P 13.0%

calculated: ("51.3% H 8.12% P 13.25%

616431

Example 3

188 g (1.04 mol) of isobutyl methyl-2-hydroxyethylphosphinate, 105 g (1.04 mol) of triethylamine. and 0.5 g of Phe-nothiazine are dissolved in 620 ml of toluene and 109 g (1.04 mol) of methacrylic acid chloride are added dropwise with vigorous stirring and without cooling. The temperature rises to 50 ° to 60 ° C. After the dropping has ended, stirring is continued for 10 hours and the mixture is cooled to -10 ° C. Now the crystallized triithylamine hydrochloride is suctioned off and the filtrate is largely freed of toluene at 120 ° C. and 35 torr in a thin-film evaporator. After addition of polymerization inhibitors, the residue is then distilled under vacuum.

220 g are obtained

O

CII3 \ »

^ PCII ^ CIIfjOC-C ^ CIIp,

CC "3> 2CIÎCH2 °" 'M U,'

Kp .: 125-131 ° C / 0.45 Torr.

This corresponds to a yield of 85% of theory. Analysis:

found: C 53.2% H 8.47% P 12.5%

calc .: C 53.6% H 8.5% P 12.4%

4th

Example 5

196 g (1 mol) of isobutyl methyl 2-hydroxyethylthiophosphinate, 101 g of triethylamine (1 mol) and 0.4 g of phenothiazine are dissolved in 500 ml of toluene and added to this with living

5 stirring while cooling 104.5 g (1 mol) of methacrylic acid chloride was added dropwise. The temperature rises to 50 ° C. E-is stirred for 5 hours and then left to stand overnight. It is then cooled and suctioned off from the triethylamine hydrochloride. The filtrate is washed out with water

10 stirred, the organic phase separated and dried with Na.SO., dried. After the solvent has been distilled off at room temperature and 1 torr, the residue is distilled after addition of polymerization inhibitors in a thin-film evaporator at 180 ° C. and 0.5 torr.

15 200 g are obtained

CIL J

^ PCH9CH9ÔC-CH = CHf.

erri ') cucii q' Il '

1 '{2 2 O CH. .

20 y 3

This corresponds to a yield of 76% of theory. Analysis:

found: C 50.0% H 7.90% P 11.3% S 12.05%

25 calc .: C 50.0% H 7.95% P 11.75% S 12.13%

Example 4

75 g (0.385 mol) of methyl (2-hydroxy-2-methylethyl) isobutyl phosphinate, 39 g of triethylamine (0.385 mol) and 0.3 g of phenothiazine are dissolved in toluene and 35 g (0.385 mol ) Acrylic acid chloride 'dropped. The mixture is stirred for 12 hours. After a further hour, methylene chloride is added and the triethylamine hydrochloride which has precipitated is filtered off with suction. After the solvent has been stripped off and polymerisation inhibitors have been added, the filtrate is distilled under reduced pressure.

57.5 g are obtained

CIIQ 0.0

3 \ ll II

^ P-CII "-CIIOC-CH = CII,

(CH3) 2CIICH20 '

2 | cil

2 '

Kp .: 95-100 ° C / 0.1 Torr.

This corresponds to a yield of 60% of theory. Analysis:

found: C 53.4% H 8.5% P 12.5%

calc .: C 53.6% H 8.5% P 12.4%

Example 6

100 g (0.66 mol) of methyl methyl 2-hydroxyethylphosphinate, 66.8 g (0.66 mol) of triethylamine and 0.3 g of Phe-30 nothiazine are dissolved in a mixture of toluene and methylene chloride and with vigorous stirring and 69 g (0.66 mol) of methacrylic acid chloride were added dropwise with cooling. After the dropping has ended, the mixture is stirred for 1 hour, then cooled to 0 ° C. and suction filtered. The filtrate 35 is distilled under vacuum after the solvents have been stripped off.

116 g are obtained

0

1

40

P-CH_-CH_-O-C-CbCH,

I.

CH,

Bp .: 147 ° C / 1.2 torr.

45 This corresponds to a yield of 80% of theory Analysis:

found: C 49.2% H 7.8% P 14.1%

calc .: C 49.1% H 7.8% P 13.9%

v