DE1230421B - Process for the preparation of 2, 4, 6-trichloro-2, 4, 6-triphenyltriphosphonitriles - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07d

German class: 12 ο - 26/01

Number: 1 230 421

File number: G 41212IV b / 12 ο

Filing date: July 29, 1964

Opening day: December 15, 1966

The invention relates to a process for the preparation of 2,4,6 - trichloro - 2,4,6 - triphenyltriphosphonitrile by reacting a solution of phenyltetrachlorophosphorane with ammonium chloride in an inert solvent.

It has been known for some time that 2,4,6-trichloro - 2,4,6 - convert triphenyltriphosphonitrile into the corresponding amine compounds and these can then condense to form higher molecular weight polymers, which have a very good heat resistance ίο exhibit. However, the industrial use of these polymers is largely economical Possibility to manufacture the intermediate 2,4,6-trichloro -2,4,6-triphenyltriphosphonitrile addicted.

2,4,6 - trichloro -2,4,6 - triphenyltriphosphonitrile can to a certain extent by reacting Phenyltetrachlorophosphorane (hereinafter referred to as 0PCI4) can be produced with NH4CI. Included however, side reactions occur in which 2c cyclic tetramers and also linear products are formed. Therefore, the yield of trimers in this reaction has so far been relatively low.

According to the invention, a process for the preparation of 2,4,6-trichloro-2,4,6-triphenyltriphosphonitriles by reacting a solution of phenyltetrachlorophosphorane with NH4CI in an inert solvent is proposed, which is characterized in that the concentration of phenyltetrachlorophosphorane in the solvent is proposed maintains to a maximum of 10 " ⁴ mol per liter of solvent during the course of the reaction.

When the concentration of 0PCIi this way is limited, in particular by the slow addition of the 0PCIj in the course of the reaction, the formation pushed back by tetrameric and higher linear products and the formation of Trimers promoted. In general, the formation of trimers can be compared to the known processes, in which mostly the entire 0PCU right at the beginning added to the reaction to be increased by at least twice.

The 0PCI4 used as starting material in this reaction can be produced by simply chlorinating 0PCI2 in an inert solvent. Usually, to chlorinate the 0PCI2, part of the solvent used later to convert the 0PCI4 obtained with NH4CI can be used. The chlorination can take place at room temperature. In this case, gaseous chlorine is passed through the solution of 0PCI2 in an inert solvent until the solution has passed through the process for the production of
2,4,6-trichloro-2,4,6-triphenyl triphosphonitriles

Applicant:

W. R. Grace & Co., New York, N.Y. (V. St. A.)

Representative:

Dr. rer. nat. J. D. Frhr. v. Uexküll, patent attorney,

Hamburg-Hochkamp, Königgrätzstr. 8th

Named as inventor:

Rip George Rice, Ashton, Md .;

Bernard Grushkin, Silver Spring, Md .;

John Theodore Ament, Baltimore, Md. (V. St. A.)

Claimed priority:
V. St. v. America August 28, 1963
(305 129)

excess chlorine turns yellow. The excess chlorine is then removed with a nitrogen atom. For the Commercially available granular NH4Cl can be used, but a reaction is preferably used finely divided ammonium chloride used. This finely divided ammonium chloride can be mechanically Grinding of commercially available ammonium chloride can be obtained. A preferred method to produce an extremely finely divided ammonium chloride, however, consists of a stream of gaseous HCl and a stream of gaseous ammonia are combined to form an ammonium chloride is precipitated with an average particle size of less than 10 μ in diameter. This extremely finely divided ammonium chloride offers a very large surface for the reaction, as a result of which a higher reaction speed is achieved. The implementation of the invention Solvents used in the process must face the reactants and the reaction products and preferably also be inert to the splitting off of hydrogen halide. Preferential

609 74-7 / 346

wise solvents for the reaction are halogenated benzenes of the general formula

is used in which X is halogen and η is a number from 1 to 3. Such solvents are, for example, chlorobenzene, bromobenzene, 1,2-dichlorobenzene and trichlorobenzene. Aliphatic hydrocarbons of the general formula are also used as solvents

example

a) Production of the raw materials
(unclaimed)

A solution of 0.2 mol of 0PCl ₂ in 350 ml of chlorobenzene was chlorinated until the reaction mixture was clearly yellow, which indicated the end of the reaction. Nitrogen was then bubbled through the reaction mixture until it was clear of water, indicating the removal of excess chlorine.

Gaseous ammonia and gaseous hydrogen chloride were simultaneously under rapid Stirring was initiated in 2700 ml of chlorobenzene until at least 0.4 mol of NH4Cl had been formed.

b) method of the invention

suitable, wherein m is a number from 6 to 10. These solvents include, for example, nonane, hexane, heptane and isohexane.

The mixture is preferably kept at a temperature between about 60 and about 150 ^° C. during the reaction. At these temperatures and the additional rate used here, the formation of the desired trimer takes place practically spontaneously when the OPCk is added. Accordingly, a longer reaction time is seldom required than for the addition of the 0PCU at a rate at which a concentration of ΙΟ "" ⁴ mol 0PCLt per liter of solvent present is not exceeded.

Subsequent to the reaction the desired trimers, can be recovered from the reaction mixture by this is first treated with water of about 80 to about 100 ⁰ C. .

Treatment with water removes any linear phosphonitrile compounds that may be present as well as traces of excess OPCk hydrolyzed. In addition, excess water present in the reaction mixture becomes due to the water treatment Dissolved ammonium chloride. After the water treatment at the temperatures mentioned, the separates Reaction mixture in two phases, one aqueous and one organic. The organic phase is separated off and now contains the desired trimer as well as small amounts formed during the reaction Amounts of tetramers. This phase is evaporated, leaving a solid, consisting of a mixture Trimeric and tetrameric residue is obtained.

If the mixture does not contain any linear compounds, it can also be used to remove excess NH4Cl are filtered and the cyclic tetramers are precipitated by concentrating the filtrate and then filtered off. Concentration then turns this flow into cyclic ones Preserve trimers.

The trimers are freed best of existing tetramers by treating the mixture with an aliphatic hydrocarbon such as pentane, hexane or isoheptane, having a boiling point below about 90 ⁰ C, which is a preferred solvent for trimers is extracted. Most of the trimers can be obtained in this way.

The invention is explained in more detail using the following example.

This suspension was then heated to reflux and the OPCk solution added under a nitrogen atmosphere at a rate of about 0.1 ml per second. With this addition the speed 0PCk concentration exceeded at any time 10 ~ ⁴ mol per liter. HCl evolved during the reaction was driven into a collecting vessel with water by means of a stream of nitrogen and titrated at intervals with normal solution.

During the reaction were in certain

10 ml samples of the solution are taken at intervals.

These were washed well with water, dried, diluted to a certain volume and the content of trimer and tetramer was determined by infrared spectroscopy (trimer: 1200 cm " ¹ , tetramer: 1300 cm" ¹ ). The results are given in the table below.

reaction time implementation Infrared analysis Tetrameres sample
Mr since the beginning % Trimeres Millimoles INI.
40 in minutes 8.6 Millimoles 1 42 22.9 7.6 - 2 87 31.8 14.8 2.39 45 3 132 44.9 21.7 3.44 4th 170 56.7 28.8 3.44 5 ' 241 74.1 38.7 4.47 6th 294 94.1 42.3 5.14 50 7 320 100 47.6 5.79 8th 2667 *) 59.8

*) All of the <Z> PCli was added within 349 minutes.

From the above values it can be seen that a total of 179.4 millimoles (ΦΡΝΟ) 3, corresponding to a yield of 89%, and 23.04 millimoles (0PNCl) ₄ , corresponding to a yield of 11%, were obtained. This corresponds to a total amount of 202.4 millimoles of phosphorus with a theoretical amount of 200 millimoles. It was found that no linear products (0PNCl) _{n had} formed in the reaction.

To illustrate the effect of 0PC1 concentration on the formation of trimers, the following comparative tests were carried out with different OPCk concentrations under different Reaction conditions carried out:

solvent temperature
(C) Maximum Average
Particle size of the NH ₁ Cl - ° / o Off
Trimeres prey
Tetrameres Attempt no. symm. Tetrachloroethane 144 tf> PCLi-
concentration
(Minor) 0.5 to 2.0 mm 2.4 24.7 1 symm. Tetrachloroethane 144 1.2 0.5 to 2.0 mm 18.3 32.0 2 symm. Tetrachloroethane 144 0.7 0.5 to 2.0 mm 20.1 29.6 3 symm. Tetrachloroethane 144 0.05 0.5 to 2.0 mm 30.2 20.1 4th Chlorobenzene 131 10-4 *) 0.5 to 2.0 mm 29.4 45.6 5 Chlorobenzene 131 0.5 0.5 to 2.0 mm 45.5 16.0 6th Chlorobenzene 131 0.2 0.5 to 2.0 mm 75.6 4.0 7th Chlorobenzene 131 10-4 *) <10 microns 89.0 11.0 8th 1,2,4-trichlorobenzene 130 10-4 *) 0.5 to 2.0 mm 28.7 37.4 9 1,2,4-trichlorobenzene 130 2.46 0.5 to 2.0 mm 42.1 36.1 10 1,2,4-trichlorobenzene 130 0.10 0.5 to 2.0 mm 71.6 8.3 11 1,2,4-trichlorobenzene . 130 10- ⁴ *) <10 microns 90.1 8.2 12th Bromobenzene 132 10 4 *) 0.5 to 2.0 mm 37.1 16.2 13th Bromobenzene 132 1.7 0.5 to 2.0 mm 47.8 20.1 14th Bromobenzene 132 0.06 0.5 to 2.0 mm 70.2 6.7 15th Bromobenzene 132 10-4 *) <10 microns 88.6 11.1 16 n-heptane 98 10-4 *) 0.5 to 2.0 mm 0 0 17th n-heptane 98 2.1 <10 microns 80.1 5.6 18th 10-4 *)

*) According to the invention.

These comparison tests show clearly that with the inventive addition of ΦΡΟ4 at a speed at which the (PPCU concentration is about 10 ^-4 moles per liter does not exceed PRESENT solvent, under given reaction conditions an improved yield is obtained of trimers.

Claims (2)

Patent claims: 1. A process for the preparation of 2,4,6-trichloro-2,4,6-triphenyltriphosphonitriles by reacting a solution of phenyltetrachlorophosphorane with NH4CI in an inert solvent, characterized in that the concentration of phenyltetrachlorophosphorane in the solvent during the course of the reaction is at most Holds 10 ~ ⁴ moles per liter of solvent. 2. The method according to claim 1, characterized in that one carries out the reaction in one halogenated benzene of the general formula in which X is a halogen and η is a number from 1 to 3, or in an alkane of the general formula C _m H2m + 2, in which m has a value of 6 to 10. Considered publications:
Journal of the Chemical Society, 1962, p. 5007.