CH619238A5 - Process for the preparation of phosphorated organic compounds - Google Patents

Abstract

Compounds of formula: <IMAGE> with x = 0 or 1, are prepared by reaction of pentaerythritol monobromohydrin with a compound Cl3P(O)x or P(OR)3, R representing an alkyl or aryl group. From the compounds obtained, it is possible to prepare polyphosphonates by autopolycondensation or by reaction with a halide GX, G representing hydrogen, chlorine, bromine, iodine or a mono- or polyvalent hydrocarbon residue, or with a halide X-CYY'-CHO, X representing chlorine, bromine or iodine and Y and Y' representing hydrogen, chlorine, bromine or alkyl residues, or with a trialkyl phosphite P(OR)3, R representing a C1-C20alkyl. The compounds III find applications in the field of plastics, one (x = 0) as a stabilising agent, the other (x = 1) as a flame retardant: the polyphosphonates can be used as flame retardants in certain polymers and synthetic textiles.

Description

The present invention relates to a process for the preparation of new products corresponding to the global formula:

^ / CH20 ^

BrCH2 C —- CH20—> P

^ CHgO ^

and heating said phosphite with a trial-coyl phosphite of formula P (OR) 3.

/ CH2 0 \

Br CH- - C - CH? 0 - P (0)

\ n /: CH2 0

(or)

In which x is an integer chosen from 0 and 1. The present invention also relates to processes for the preparation of polyphosphonates of generic formula:

The present invention relates to a process for preparing the bicyclic phosphite of the monobromhydrin of pentaerythol as well as bicyclic phosphate and a new family of polyphosphonates derived therefrom.

A number of bicyclic esters of phosphorous acid (formula I) and phosphoric acid (formula II) having the structure of bicyclo (2.2.2) octane are known.

30

ch2

z c —- ch

V. ' /

(I)

0

■ 0

45

: h.

-o

The first phosphites and phosphates of types I and II (Z = CH3, C2H5, and higher alkyls, HOCH2) seem to have been discovered by the chemists of HOOKER Chemical Corp. (English patent 889 338 published on February 14, 1962 with priority from the United States of America of July 21, 1958), but the first publication relating to these compounds in fact goes to JG VERKADE and LT REYNOLDS (J. Org. Chem. 1960 , 25, 663) with the synthesis of phosphite I (Z = CH3).

Other similar phosphites with Z = C2H5, HOCH2, CH3COOCH2, CH2 = CH (CHs) COOCH2, CH3 (CH2) 3 CH (C2H5) COOCH2 were prepared by O. NEUNHÖEFER and W. MAIWALD (Chem. Ber. 1962, 95.108) and by WS WADSWORTH jr and WD EMMONS (J. Am. Chem. Soc. 1962, 84.610); the latter also described phosphates, II with Z = C2H5 and CH2 = CH (CH3) COOCH2.

(G) yE (A) n-l (X) n-p + y (P03R2) p

(IV)

35

in which (G) is a residue chosen from the group consisting of hydrogen, halogens, the rest

0CH_

DP —- 0CH_ C - CH -

\ 2/2

OCH:

and mono- and polyvalent hydrocarbon residues, the residues CYY '= CHO - where Y and Y' are chosen from hydrogen, chlorine, bromine and alkyl residues.

/ CH2- x

.C CH ~ 0 IN (II)

2 -y '

OCH,

(A) is

55

6 "

P

II

0

OCH,

CH,

CH,

(B) is

"5

OCH,

p - och2 - C - CH

OCH-

619,238

4

(E) is A when y = 1 or B when y = 0,

(X) denotes identical or different atoms chosen from Br, Cl and I, one at most of which can denote Cl or I when y = 1 and all denote Br when y = 0,

(R) is an alkyl radical containing from 1 to 20 carbon atoms,

y is an integer chosen from 0 and 1,

n is an integer up to 500,

p is an integer between 0 and n + y.

The licensee successfully prepared the phosphite of formula I in the crystallized state with Z = BrCKb (formula III in which x = 0). This result was entirely unexpected since such a phosphite, having in its molecule a very reactive halomethyl group and a tertiary phosphite group, which is also very reactive, could a priori be considered as too capable of self- condensation to be isolable in the pure state.

The licensee also successfully prepared the bicyclic phosphate of formula II in which Z = BrCKk (III, n = 1) by oxidation of phosphite (III, x = 0).

The process according to the invention is characterized in that the pentaerythrol monobromhydrin is reacted with a compound of formula CbP (0) x or P (OR) 3, in which x has the above meaning and R represents a group alkyl or an aryl group.

Thus, the phosphite of formula III (x = 0) is obtained by reaction of the phosphorus trichloride with the onobromhydrin of pentaerythrol according to the equation:

PCh + (HOCH2) 3C-CH2Br - »III + 3 HCl

This reaction can take place between -40 and 100 ° C and preferably in the presence of one or more inert diluents such as hexane, heptane, benzene, toluene, xylene, eumene, chlorobenzene, chloroform, ether, tetrahydrofuran, dioxane. A tertiary amine can optionally be used to neutralize the hydrochloric acid released; for example, triethylamine, pyridine, alpha-picoline, dimethylaniline, diethylaniline, N-methylmor-pholine can be used for this purpose.

The phosphite of formula III (x = 0) is also prepared by transesterification of a trialkyl or triaryl phosphite with pentaerythrol monobromhydrin in the presence or absence of a basic catalyst, for example a hydroxide, alcoholate, phenate, hydride , amide, carbonate or hydrogen carbonate alkali, or alkaline earth, an aluminum alcoholate or a tertiary amine. The reaction takes place in this case advantageously under a pressure between about 0.5 and 50 mm Hg at a temperature between about 20 and 120 ° C.

The stability of phosphite (III, x = 0) is limited: initially completely soluble in benzene, it is only partially soluble after a few days of storage at room temperature away from humidity. It should therefore preferably be stored in a cold room or used immediately after its preparation.

The oxidation of phosphite (III, x = 0) to phosphate (III, x = 1) can be carried out using several oxidizing agents such as concentrated hydrogen peroxide, organic peroxides, ozone, nitrogen oxides or oxygen / nitrogen oxide combinations, alkaline permanganates. Here too, preferably, in the presence of one or more inert solvents such as hexane, heptane, benzene, toluene, xylene, eumene, chlorobenzene, chloroform, tetrachloromethane, ether, acetone, acetonitrile, ethyl acetate.

Phosphate (1H, x = 1) is also obtained by direct reaction of phosphorus oxychloride with pentaerythritol monobromhydrin.

The products of formula IV in which y and p are zero and X = Br are obtained by polycondensation of phosphite (III, x = 0). This takes place by simple heating of said phosphite, at a temperature between 80 and 250 ° C., optionally within an inert heavy solvent, such as xylene, eumene, tetralin, chlorobenzene, orthodichlorobenzene, trichloroben-zenes, monochloronaphthalene.

In the case where the reaction is not pushed until the total disappearance of the three-coordinated phosphorus, it obeys the equation:

n (HI, x = 0) ^ B (A) n-i (Br) n in which A, B and n have the meaning indicated above. The polyphosphonate obtained will in this case have an open “tree” structure 45 (type 0) as shown in the following diagram:

Type 0 polymer

15

20

25

30

35

Br Br Br A

/ \ Br Br

When the reaction is pushed to the complete disappearance of the three-coordinated phosphorus, it obeys the equation:

nIII (x = 0) - ”(A) n (Br) n where A and n have the same meaning as before.

5

619,238

In this case the polyphosphonate obtained will generally have a higher molecular weight than in the previous case and will be “closed” (type F), that is to say that it will include an additional branch-root junction as illustrated in the diagram below. -after:

Type F polymer

The mixed polyphosphonates of formula IV in which y = 1, p = 0, (E) is (A) and (G) is chosen from hydrogen, halogens and mono- and polyvalent hydrocarbon residues, 2s are obtained by heating phosphite (III, x = 0) with a halide GX in which X denotes chlorine, bromine or iodine. As halide GX, any known halide may be used to give the trialkyl phosphites the so-called MICHAELIS-ARBUZOV reaction, leading to a phosphonate; this reaction will be written here:

nin or> + GX - »G (A) n (Br)„ x

B (A) n-i (Br) n J 35

The polyphosphate obtained will in this case also have an open “tree” structure which can be deduced from that of the polymer (0) above by simply replacing B with G.

The halide GX could also be of the type of the halides known to give with trialkyl phosphites the reaction known as of PERKOW leading to a vinyl phosphate. In this case, the polymer obtained can be further illustrated by the structure (0) above, modified by replacing B with a remainder CYY '= CH - 0 -, Y and Y' having the meaning given above.

As an example of a halide GX which can be used, mention may be made of: chlorine, bromine, iodine, chlorides, bromides and iodides of hydrogen, methyl, ethyl, propyl, butyl, allyl, benzyl, p-xylylene dichloride, acetyl, acryloyl, methacryloyl chlorides, methyl chloro-methyl ether, chloroform and chloroacetic esters, chloral or phosphate (III, x = 1) .

Mixed polyphosphonates of formula IV in which p is not zero, of a second type are also obtained by heating together the phosphite (ni, x = 0) with another trialcoyl phosphite (RO) 3 P, where R is an alkyl containing from 1 to 20 carbon atoms. The structure of the polyphosphonate obtained can be deduced from those of types 0 and F above by replacing all or part of the bromine atoms by residues - PO (OR) 2, the global reaction then being written, either:

60

n (m, x = 0) or

B (A) „- i (Br) n

}

65

is:

n (III, x = 0) or

(A) n (Br) n

}

+ m (RO) 3P - »(A) n (Br) n-m (P03R2) m + mRBr

45

50

+ m (RO> PB (A) nl (Br) nm (P03R2) m + mRBr where A, B and n have the same meaning as above and where m is an integer between 1 and (n-1) .

Phosphite (III, x = 0) finds applications as a stabilizer for plastics and as an intermediate for the preparation of insecticides.

Phosphate (III, x = 1) finds applications as a flame retardant for plastics and synthetic fibers and as an intermediate in the preparation of functional phosphoric esters.

Due to their high phosphorus and bromine content and their highly branched structure, polyphosphonates derived from phosphite III are likely to find numerous applications, for example as flame retardant additives with low migration speed in vinyl or acrylic polymers and in synthetic textiles.

Example 1 Preparation of bicyclic phosphite from bis (hydroxymethyl) -2,2 bromo-3 propanol

0.1 mole of phosphorus trichloride and 0.1 mole of monobromhydrin were placed in a flask fitted with a thermometer, a dip tube, a slow mechanical stirrer and a reflux condenser with dry ice. pentaerythritol. The agitator was started as well as a light bubbling of dry nitrogen.

Under the effect of the release of hydrochloric acid, the temperature first dropped from 20 to 0 ° C and then slowly rose to its initial value.

After 5 hours, the mixture was diluted with 25 ml of hexane and 12 ml of benzene and then heated for another 2 hours at 40 ° C and then 1 hour at 60 ° C, without ceasing the bubbling of nitrogen. Upon cooling, crystals appeared which were quickly spun on a sintered glass filter and washed with a 1/1 mixture of hexane and benzene. After drying under vacuum, 22 g of colorless, hygroscopic crude crystals were obtained; yield = 97%.

A new crystallization in a mixture V4 of hexane and 3 / 4benzene provided us with purified crystals, melting clearly at 88 ° C and titrating P% = 12.96 (calc. = 13.67) and Br% = 34.10 (calc. 35.2). The magnet resonance spectrum

619238

6

The proton of the phosphite dissolved in the deuterochloro-form, has a signal at 4.03 ppm (PO CH2 groups) and a signal at 3.00 ppm (ClfcBr group), in the theoretical ratio 6/2, the chemical shifts being counted with respect to hexamethyldisiloxane as an internal standard.

Example 2 Preparation of bicyclic phosphate of bis (hydroxymethyl) -2.2 bromo-3 propanol A solution of 20 g of the above phosphite (freshly prepared) in 500 ml of a 1/1 mixture of hexane and benzene was stirred vigorously at room temperature in an atmosphere composed of oxygen and nitrogen tetroxide N2O4. A precipitate formed quickly, which was collected on a filter, washed with hexane and dried under vacuum. 21.2 g of colorless crystals were obtained, melting at 161-162 ° C and titrating P% = 13.4 (calc. = 12.8), Br% = 33.2 (calc. = 32.9).

Example 3 Preparation of a polyphosphonate 25 g of phosphite prepared as in Example 1 were heated in a metal bath in a glass cylinder fitted with a piston, the latter being gradually pressed during the condensation (which is accompanied of a contraction). The temperature was raised from 150 to 200 ° C over the course of 5 h and then the latter temperature was maintained for a further 7 h. A glassy, colorless, translucent polymer, hard at room temperature, softening at around 200 ° C. was obtained.

Example 4

Preparation of a phosphate-polyphosphonate As in Example 3, 2.5 g of phosphate of Example 2 were heated with 22.5 g of phosphite of Example 1, for 5 h at 160- 190 ° C then for 9 h at 200 ° C. A colorless, hard, glassy polymer was obtained at room temperature.

Example 5 Preparation of a mixed polyphosphonate Was heated as in Example 3.1 g of p-xylylene dichloride with 24 g of phosphite from Example 1, for 3 h at 130-200aC then for 8 h at 200 ° C. A glassy, straw-yellow polymer which was hard at room temperature was obtained.

Example 6

Preparation of a phosphate-polyphosphonate Was heated as in Example 3.1 g of anhydrous chloral freshly redistilled with 24 g of phosphite from Example 1, for 2 h at 90-150 ° C and then for 2 h at 150 -180 ° C and 7 h at 180-190 ° C. A hard glassy polymer was obtained at room temperature.

Example 7 Preparation of a mixed polyphosphonate A mixture of 5 g of triethyl phosphite and 20 g of phosphite of Example 1 was heated as in Example 3 for 6 h at 150-190 ° C and obtained a colorless polymer, remaining soft at room temperature.

15

20

B

Claims (6)

619,238 2 15 CLAIMS 1. Process for the preparation of a compound corresponding to the formula: / CH2 ° \ BrCH „—C — CH.O — P (0) (IE) '\ / CH20 in which x has the value 0 or 1, characterized in that the pentaerythrol monobromhydrin is reacted with a compound of formula CbP (0) x or P (OR) 3, in which x has the above meaning and R represents an alkyl group or an aryl group. 2. Method according to claim 1, characterized in that a trialkyl or triaryl phosphite is involved and that the reaction is carried out in the presence of a catalyst chosen from hydroxides, alcoholates, phenolates, hydru -res, amides, carbonates and hydrogen carbonates of alkali or alkaline earth metals, aluminum alcoholates and tertiary amines, under a pressure of between 0.5 and 50 mm Hg, at a temperature between 20 and 120 ° C. 25 3. Method according to claim 1, characterized in that the compound obtained, of formula ni in which x has the value 0, is oxidized to the corresponding compound for which x has the value 1. 4. Method according to claim 3, characterized in that the oxidation is carried out by means of a mixture of oxygen and a nitrogen oxide. 5. Process for the preparation of polyphosphonates of formula: B (A) n-i (Br) n or (A) n (Br) n in which B represents the group .OCH, G (A) n (Br) nX in which G represents hydrogen, a halogen or a mono- or polyvalent hydrocarbon residue, A represents the group / 0CH2 \ / o ^ ocH, .r ch2 ~ - -ch2— X represents chlorine, bromine or iodine and n is an integer up to 500, characterized in that a phosphite of formula is prepared by the process according to claim 1: 20 30 / uun2 \ ■ OCH • OCH, P -CH, 40 / CH2o. BrCHp C-— CHo0 P \ 2 / NCH20 / and heating said phosphite with a halide of formula GX. 7. Process for the preparation of polyphosphonates of formula: CYY '= CH-Ö- (A) n-i (Br) n in which A represents the group ✓ 0CH2Vs ^ / CH2 0 X0CH2X CH2 Y and Y 'represent hydrogen, chlorine, bromine or alkyl residues and n is an integer up to 500, characterized in that a phosphite of formula is prepared by the process according to claim 1: A represents the iN group OCH2 CH2 * .vs OCH, WCH, and n represents an integer up to 500, characterized in that a phosphite of the formula is prepared by the method according to claim 1: 50 ^ CH20v BrCH „C CHo0 I \ 2 / xCH20 / and that said phosphite is heated with a halide of formula X-CYY'-CHO in which X represents chlorine, bromine or iodine. ss 8. Process for the preparation of polyphosphonates of formula: BrCH, ^ CH20, ■ CH2 ° —pP ^ ch2O ^ 60 B (A) n-l (Br) n-m (P03R2) m OR (A) n (Br) n-m (P03R2) m in which B represents the group „0CH, 65 / uun2 \ -OCH and that said phosphite is heated with itself by autopo-lycondensation at a temperature between 80 and 250 ° C. 6. Process for the preparation of polyphosphonates of formula: ^ OCH -CH, 3 619,238 A represents the group .OCH K OCH R represents an alkyl radical containing from 1 to 20 carbon atoms, m is an integer between 1 and (n-1) and n is an integer up to 500, characterized in that one prepares by the process according to claim 1 a phosphite of formula: The phosphite (I) and the corresponding phosphate (II) with Z = H were not prepared until later by E. J. BOROS et al. (J. Am. Chem. Soc. 1966, 88,1.140). Phosphate II with Z = NO2 had been prepared in 1926 by F. ZETZSCHE and E. ZURBRÜGG (Helv. Chim. Acta 1926,9, 298); its synthesis was taken up by W. H. CHANG (J. Org. Chem. 1964, 29,3.711) who simultaneously described phosphates II with Z = CöHs and CöCLs - OCH2. Finally G. KAMAI and E. T. MUKMENEV (Jour. Obsch. Khim. 1963,33,3.197) reported the preparation of a diphosphite corresponding to formula I with Z = (C2HsO) 2 POCH2-