DE1230422B - Process for the preparation of cis- and trans-2, 4, 6-trichloro-2, 4, 6-triphenyl-triphosphonitrile - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07d

German class: 12 ο - 26/01

Number: 1230 422

File number: G 41876IV b / 12 ο

Filing date: October 28, 1964

Opening day: December 15, 1966

: The present invention relates to manufacturing of cis- and trans ^ Ao-trichlor ^ Ao-triphenyltriphosphonitrile.

Both cis and trans-Aö-trichloro-Aö-trirphenyltriphosphonitrile [ _{abbreviated to cis- or trans- (NP0Cl) 3} ] are valuable intermediates for the production of inorganic polymers. As a result of condensation with ammonia at elevated temperatures, these compounds form highly crosslinked polymeric structures which are stable even at high temperatures.

It is known that cis and trans (NP0Cl) _s can be prepared at temperatures of 60 to 150 ° C by. Implementation of phenyltetrachlorophosphorane with commercial ammonium chloride of coarse particle size in the presence of a hydrocarbon as an inert solvent. However, in addition to the desired trimeric compounds, this process also produces considerable amounts of tetrameric phosphonitriles (NPOC1) ₄ and linear polymers (NPOC1) «. The cost of preparing crosslinked phosphonitrile polymers from (NP0C1) ₃ could be significantly reduced if a convenient way of obtaining good yields of (NP0C1) ₃ were available.

It was known that cyclic trimers of the corresponding bromine compounds by reaction can be represented by phenyldibromophosphine with bromine and ammonium chloride. This reaction However, it is much too slow for a technical implementation, since a yield of only 60% is only possible is reached after 12 days. On the other hand, it was already known that cyclic trimers and tetramers Phosphorus nitrile chlorides by reacting phosphorus trichloride with finely divided ammonium chloride can be won. Here, too, the yield achieved was low and was only about 60% and underneath.

It has surprisingly been found that the yield of (NP0C1) _{3 is increased} considerably (up to 95% based on the phosphorus compounds used) and the formation of linear products can be completely avoided if a solution of phenyltetrachlorophosphorane is slowly converted into a suspension of finely divided Ammonium chloride with an average particle size below 10 μ is added. The reaction is complete in a maximum of 24 hours. However, this process still has certain disadvantages on an industrial scale. On the one hand, a reaction vessel is required in which phenyldichlorophosphine can be reacted with chlorine in a suitable solvent to obtain phenyltetrachlorophosphorane.

Process for making ice cream and

triphosphonitrile

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:

Bernard Grushkin, Silver Spring, Md .;

Rip George Rice, Ashton, Md. (V. St, A.)

Claimed priority:

V. St. v. America October 30, 1963 (319 960)

Since this solution of phenyltetrachlorophosphorane is very concentrated, it must be used during the reaction period Stay hot to prevent clogging of the lines by the crystallization of the phenyltetrachlorophosphorane avoid. Furthermore, the reaction mixture of ammonium chloride and phenyltetrachlorophosphorane constantly diluted by adding the phenyltetrachlorophosphorane solution during the reaction.

To avoid these disadvantages, especially to reduce the outlay on equipment and to There is a great need to achieve better control of the concentrations of the starting materials for a more convenient procedure.

According to the invention there is accordingly a process for the preparation of cis- and trans-2,4,6-trichloro-2,4,6-triphenylphosphonitrile proposed, which is characterized in that one chlorine and phenyldichlorophosphine with a suspension of ammonium chloride with an average particle size below 10 microns in an inert liquid reaction medium at 60 to 150 ° C while introducing the chlorine into the suspension at a rate of 0.002 to 0.01 moles of chlorine per minute per mole of phenyldichlorophosphine.

The inert reaction medium used in the process according to the invention is preferably a non-polar one Hydrocarbon, especially a saturated aliphatic hydrocarbon with about 6 to 10 carbon atoms, used. Halogenated hydrocarbons, which are not, are also used as the reaction medium

609 747/3 «

easily split off hydrogen chloride, such as B. tetrachlorethylene and halogenated benzenes with 1 to 3 halogen atoms, suitable. Examples of suitable reaction media are both straight-chain and branched-chain isomers of hexane, heptane and octane and their fluorine-, chlorine- and bromine-substituted derivatives with up to 6 halogen atoms. Of the substituted benzenes, for example, chlorobenzene, dichlorobenzenes and 1,2,4-trichlorobehzene are suitable. The common features of the listed reaction media are a very low polarity and a boiling point in the range between about 60 and 200 ^° C.

The ammonium chloride suspension of the specified particle size required as a starting material can easily be by mixing the finely divided ammonium chloride with one of the listed reaction media uniform vigorous stirring. The finely divided ammonium chloride can with HiUe one of the known methods, e.g. By thorough mechanical grinding. The cheapest Method, however, is the reaction of ammonia with gaseous hydrogen chloride, whereby the known mists of ammonium chloride form extremely small particle sizes. The most convenient is the Association of ammonia with hydrogen chloride carried out in an inert reaction medium, which can then also be used to obtain the desired trimeric phosphonitrile. Preferably Ammonium chloride suspensions are generally taken which are about 0.05 to 0.2 parts of finely divided ammonium chloride to 1 part of suspending agent (with particles are always Parts by weight meant).

After the ammonium chloride dispersion is formed, the phenyl dichlorophosphine is added to the mixture. This order of addition does not have to be must be adhered to, but it is generally the most convenient. Preferably that will Process according to the invention carried out in such a way that one adds to the ammonium chloride suspension already prepared so much phenyl dichlorophosphine admits that this is about 0.25 to 0.5 mol of phenyl dichlorophosphine per 1 mol • Contains ammonium chloride. That big excess of ammonium chloride is not absolutely necessary, but is generally preferred because it provides a complete and thorough reaction of the more expensive phenyldichlorophosphine is ensured.

The mixture obtained is then heated to the reaction temperature. If the reaction medium boiling at the temperature at which the reaction is carried out, the reaction is convenient carried out under reflux.

As soon as the reaction mixture has reached the desired temperature, gaseous chlorine with a Initiated speed of 0.002 to 0.01 moles of chlorine per mole of phenyldichlorophosphine per minute.

According to another embodiment, the ammonium chloride dispersion heated to the reaction temperature can be added also the phenyldichlorophosphine with stirring at about the same speed like adding the chlorine at the same time. A small excess of phenyldichlorophosphine should preferably be used be present so that the introduced chlorine reacts with the phenyldichlorophosphine and not leaves the reaction vessel again. This procedure ^ Variant is particularly favorable for continuous implementation, an advantageous speed for the simultaneous addition of phenyldichlorophosphine

ίο and chlorine is about 0.001 to 0.50 moles per minute per mole of ammonium chloride.

If the reaction is carried out batchwise, chlorine is usually preferably passed in until until no further hydrogen chloride is given off by the reaction mixture.

When the end of the reaction is indicated by the cessation of the evolution of hydrogen chloride, the cis- and trans- (NP0Cl) ₃ are isolated by filtering off the ammonium chloride and evaporating the filtrate to dryness, whereby a mixture of almost pure cis- and trans- (NP0Cl) _{3 is} obtained will. This product can, if necessary, be further purified by extraction with a paraffinic hydrocarbon containing 4 to 7 carbon atoms.

Such hydrocarbons preferentially dissolve the trimeric compounds and can therefore be used for separation the same are drawn from incidentally formed tetrameric compounds.

The following examples explain the invention in more detail.

For example

200 millimoles of phenyl dichlorophosphine was added to 75 ml of chlorobenzene, which is a large molar excess of ammonium chloride produced from gaseous ammonia and hydrogen chloride contained. The solution was brought to the boil, a slight evolution of hydrogen chloride being observed became. This evolution of hydrogen chloride at the beginning is due to the reaction of phenyldichlorophosphine recycled with ammonium chloride. This slow side reaction is unimportant as it affects the overall yield hardly and favorably influenced by trimeric compounds. After purging with nitrogen gaseous chlorine was then introduced into the reaction mixture initiated. The rate of hydrogen chloride evolution increased almost instantly. After 45.5 millimoles of chlorine has been added at a rate of 0.244 millimoles per minute were, the introduction of chlorine was interrupted and a sample for the infrared spectroscopic examination removed from the reaction flask. The remaining reaction mixture was left for a few minutes refluxed, whereupon chlorine in different batches at rates of 0.121 and 0.35 millimoles per minute was initiated and the same procedure repeated as above. The received The results are compiled in the following table:

attempt

1
2
3

speed
the addition of Cl ₂

(mmol / minutes)

0.244
0.121
0.35

Reaction time (minutes)

186 100 160 total

developed

HCl amount

(mmol)

196.3
264.0
505.0

NP0Cl yield

Trimer

76.2
78.3
95

%
Tetramer

0
0

2.5

From the above figures that the desired trimeric compounds in a yield of 95% in addition to only 2.5 ° / ₀ tetrameric compounds are obtained at a chlorine feed rate 0.002 to 0.007 mole of chlorine per mole of phenyldichlorophosphine per minute in the reaction mixture arises.

Example 2

A mixture of 102.5 millimoles of phenyl dichlorophosphine and 215 millimoles of finely divided ammonium chloride (produced by the conversion of gaseous Ammonia with hydrogen chloride) was heated to 132 ° C. under reflux in 600 ml of chlorobenzene. the The amount of hydrogen chloride evolving was continuously measured and thus the rate of the reaction certainly. Chlorine diluted with nitrogen was then added to the mixture with a Introduced at a rate of 0.35 millimoles of chlorine per minute. The evolution of hydrogen chloride increased to it immediately. Samples taken were examined for their content by IR spectroscopic examination analyzed on trimeric and tetrameric compounds. The results of this experiment are as follows Table listed.

attempt

speed
the Cla addition

(mmol / minutes)

Response Time (Minutes) Total

developed

HCl amount

(mmol)

NP0Cl yield

0 /

/O
Trimer

%
Tetramer

1
2
3
4th

0.35
0.35
0.35
0.35

137
185
245
24 hours 100
193.2
300
408.3

76.0
82.9
69.2
86.4

0
0

0.72
6.48

Example 3

A suspension of 215 millimoles of finely divided ammonium chloride in 600 ml of chlorobenzene was heated under reflux at 132 ⁰ C. Phenyldichlorophosphine was then added at a rate of 0.35 millimoles per minute, and after a few minutes the introduction of chlorine was started at a rate of 0.35 millimoles per minute as well. The rate of evolution of hydrogen chloride was measured. The yield of (NPOC1) ₃ was 95%.

It is noteworthy that the slow addition of phenyldichlorophosphine simultaneously with the Chlorine the side reaction with the finely divided ammonium chloride is kept to a minimum.

Claims (6)

Patent claims: 1. Process for the preparation of cis- and trans-2,4,6-trichloro-2,4,6-triphenylphosphonitriI, characterized by the fact that chlorine and phenyldichlorophosphine are combined with a suspension of ammonium chloride with an average particle size below 10 microns in an inert liquid reaction medium at 60 to 150 ° C while introducing the chlorine into the suspension with a Reacts rate of 0.002 to 0.01 moles of chlorine per minute per mole of phenyldichlorophosphine. 45 55 2. The method according to claim 1, characterized in that the reaction with a Performs ammonium chloride suspension containing 0.25 to 0.5 moles of phenyl dichlorine per mole of ammonium chloride contains. 3. The method according to claim 1 and 2, characterized in that the phenyldichlorophosphine and simultaneously adding gaseous chlorine to the ammonium chloride suspension. 4. The method according to claim 1 to 3, characterized in that the phenyldichlorophosphine and the chlorine to the suspension at a rate of from 0.001 to 0.50 moles per minute adding per mole of ammonium chloride. 5. The method according to claim 1 to 4, characterized in that the reaction with a Ammonium chloride suspension carries out the 0.05 to 0.2 parts by weight of ammonium chloride per part by weight Contains reaction medium. 6. The method according to claim 1 to 5, characterized in that the reaction is carried out in one optionally halogen-substituted saturated hydrocarbon which does not split off hydrogen halide tends to perform as a reaction medium. Considered publications:
Notified documents of Belgian patent No. 621 384;
Inorganic Chemistry, 2 (1963), No. 3, p. 659. 609 7 + 7/347 12.6fi © Bundesdruckerei Berlin