DE1945252C - Process for the preparation of aryl chlorosilanes - Google Patents

Description

This solution at ri ITl a process / ur || ers | e | - Ιιιημ of arylclilorsilanes by I 'niseizinig of ! lydiidochlorosilicate with aromatic hydrocarbon oils linier irradiation.

Arylchlorosilanes, such as dipuenyldiehlorosilane or l'he- s nylrichlorosilane, are used as starting materials for Silicone oils, silicone varnishes and silicone rubber are important.

The previously proposed. Process / for making these compounds were: ">

a) The (! rignard process, in which one uses aryltrichlorosilane with Ilalogen-Matmesiumniethyl or Methyllrichlorosilane with halogen magnesiai> l / brought about a reaction or by adding silicon chloride with halogeu magnesium aryl iimset / te.

h) I 111 method dchydiicrt or wherein Melhyldichlorsilan or trichlorosilane together with metallic aromatic hydrocarbons using boron n> chloride as a catalyst in dom derarlige chlorosilanes using \ on chlorinated aromatic hydrocarbons iliirchChlorwasserstorfabspalliingdargeslclll be. J5 ei The Direkisvnthese from 1iK-1.1lliM.hcm Siliuam and Chlorhcnzol.

d) The process of copropolis tunneling of l'heinllrichlorsilan with I rimellnlchlorosilan.

\O

Of these four procedures, the (irigtuml procedure a) the disadvantage that a large amount of ether has to be used and all of the linlfeiuung “Ler by-products causes problems, dear Method n) must involve dehydration and the (hlor- is ivasscrstollabspalUing at holier I cmperatur and oiler linier high pressures duichgcliihit graze if 111,111 ilic Dircklsvnlhese c) anucnilcl. wild Pheu.lliit'hlorsilan as the desired product merely al-. Neheiipiodukl von Diphenyldichlorsilau ei hallen und | o ilies in small quantity: especially when Phcn) lia, likalc He differentiates between various substitution radicals. And the synthesis according to this direct NUilinde olllnals difficult. Die Coproporlioniei ιιημ ill li.it den Disadvantage, that they are unler high I empei.iliuen and is lioiien printing are carried out muli, thereby containing the reaction product not / 111 reaction succeeded l'henyltrichlorosilane. the only s-Jiwer abüelieiml Can be.

It has also been suggested to induce the production of aryl chlorosiians (cf. USSR-Paienischrifl 162 842), a mixture of animal hydrocarbons and hydrostol-chlorosilanes, e.g. a mixture of benzene and methyldichlorosilane or of benzene and irichlorosilane, with light from a filament lamp to irradiate, giving phenylmethyldichlorosilane or phenylrichlorosilane.

With this method, it is possible to obtain the product you want, without any By-products that have to be laboriously separated and under comparatively mild conditions. However, the yield of the desired organochlorosiianes with aromatic radicals is compared to that Hydridochlorosilane and, to give an example, is low in the synthesis of phenylmethyldichlorosilane 12 percent by weight and about 39 percent by weight in the synthesis of phenyllrichlorosilane. I! Pleasant in this case it is also that there is most of it Methyldichlorosilane is converted into worthless methyltrichlorosilane and the reaction did not succeed Material in worthless Siliciuniteirachlorid I-.s is therefore difficult to use organochlorosilane after this procedure with a different aromatic radical than phenylehlorsilane and phenylmelhyldichlorosilane.

Lün / iel of Irlindiing is a process to find that is free from the above-mentioned disadvantages and from chlorosilanes with a Si II bond and aromatic compounds emanates, to another aim that is considered to be high bulges achieve extensive suppression of by-products that can only be separated with difficulty or have a low groove / value.

I> ie ( 'invention is characterized in DAT Irichlorsilan one or methyldichlorosilane Ben mil / ol or an alkyl or Ilalogen-phenoxy-Bcn / ol in (iegenvvart of (I maybe irradiated hlor nut a that is at least .Κ) ¹¹ »Its radiation wavelengths outside of the 38 (K) A in hl.

After eiliudungsgemäl.len methods can at atmospheric pressure and room temperature arylchlorosilanes with various aromatic residues in good yields are produced, accompanied by only minimal amounts of by-products such as Siliciumlelraclilorid or Mclhvltrielilnrsilan i \\ .- Icdiglich small groove / werl have

The eiliiuhingsgc-m.iHen procedure / uginndc lying ·. · Reaklimi k.inn like IuIiM d.mvsU lh wcnleii

K II,), ,, (1,, SiII ♦

) - 'll, l, ,, CI ₁₁ Si

/ · IKI

l) where η 2 or .V Irichliu .ilane is preferred over methyldichlorosilane because of its better reactivity. / means a Mkvl. IaIotten- or Phenoxybenzolresl.

The production of arylchloisilanes by this method is presumably due to the deposition of In -irr radicals on Cir and the initial photolysis of the chlorinolckiilc (Cl ₁ -'2Cl) in the reaction mechanism. It can be assumed that the above-mentioned free radicals cause the hydrogen atoms to isolate themselves from the chlorosilanes with the silicon bond through the formation of chlorosilyl radicals, which in turn react with the oil nucleus in the aromatic compounds. When using a giol.le I khtmcngc with wavelengths of over 5 (KN) A! winds, the accumulation of by-products, such as ss SihcuiiiiUiraehlorid. although the chlorine atoms are absorbed. that covers a certain range of wavelengths only U (K) A .ils Spii / e. I 'm at the optimum Ausb. ^n-1 .- Only the desired Arylchlorsilan her / Ti -, Lelli-n. mii'.sen least K) ¹ or more preferably O fco about -tu: have a wavelength u animal whole radiation, does not exceed the Woo. This can be clearly seen from the fact that a renk lion will certainly enter, by which, for example, some phenyllrichlorosilane is produced when a (iliih - (> ·, fiideiilaniji Have wavelengths that do not exceed 38OOA Ic, hole results in those I all in which d, 1 Siralilenanlcil with wavelengths above

5 (KM) Λ is comparatively large, since the amount of silicon ^{tetnichloride as a by-product increases sharply in comparison to the proportion of the desired I 1} IiLMIyIIrIcI) Ii) TSiIUnS. By the method according to the invention, however, l'henyHrichlorosilane can be produced in a proportion of approximately 70%.

The method used in the invention Light source can, in order to meet the desired conditions specified above, in particular a high pressure mercury lamp, a low pressure mercury lamp, be a xenon arc lamp and a hydrogen arc lamp.

Chlorosilanes with a Si - bond and aromatic compounds are mixed in a molar ratio of 5:95 to ^l ) l): l () or preferably from 10:90 to 70:30. The chlorine, in the presence of which the reaction is carried out, is introduced in the gaseous state into the bottom of the mixture of the abovementioned chlorosilanes and aromatic compounds in such an amount that it does not escape in the gaseous state. The irradiation reaction is therefore carried out when the chlorine is absorbed by the liquid layer. If the chlorine gas has previously been diluted with an inert gas such as nitrogen, absorption by the mixed liquids will be the same, and more favorable results will be obtained can be regulated, but the amount of chlorine added during the reaction process can be 0.1 to 3 mol per MoISi H radical ... the more preferred 0. "to 2 mol.

I) The reaction time can vary from 0.5 to 23 hours. it is usually noticeable. The amount of light used in animal irradiation -all large enough to form free chlorine radicals in such an amount that the reaction lasted according to the explanation given by I. nergy is from I to 1000 VV. Bc \ or / ug 5 to 5 (K) VV per kilogram of reaction liquid.

In the HmMiLk I recommend working economically the implementation of the fulfillment At room temperature and atmospheric chemistry Pressure. Then there are no difficult scoops. even if the I emperatur during the work pre-μaι) l! s according to this process increases somewhat while the reaction is continuous.

Ie: Irligation is explained by the examples. where the proportions consistently mean (weight proportionc.

like example 1

In the middle of a reaction gap. the one with a Kücknusskiihler. a fhermometer and a (lasrohr equipped. a KK) -W-Ilochdruck Quecksilberlampc-mounted (54 ¹ O of the emitted radiation had vs wavelengths. 3K (X) A not iiberschrilten). the lamp being so equipped. that it was cooled on all sides with heaving water. 271 liters of chlorine chloride and 1404 liters of benzene were added to the reaction vessel. After the batch was stirred, the alinospluire inside the reaction vessel was replaced with nitrogen and the mercury lamp was turned on, while gaseous chlorine was introduced into the bottom of the mixed liquid layer, the reaction being carried out for 3 hours. 1711 parts of the product were obtained from the constituents shown below. The yield of phenyllrichlorosilane compared to the raw material trichlorosilane was 73%.

(icwithupro / fni

Trichlorosilane I 9

Silicon tetrachloride 11

Phenyltrichlorosilane 15 8

High boiling point substance ''.'.'.'.'. HA

Control attempt 1

1 in the same or similar experiment as that described in Example 1 was carried out with the Modification that a 100 W filament lamp (0.5% of the rays emitted by these had wavelengths not exceeding 3800 A) instead of the H) O - Vv - high pressure mercury lamp was used. There were 1720 parts of the product with the obtained below residual parts. The yield of phenyltrichlorosilane compared to the raw material trichlorosilane was only 38.6%.

Trichlorosilane. "" .. 'Γ.9

silicon tetrachloride 7.7

B ⁱⁿ inches 65 7

i'henyltrichlorosilane 84

High boiling point substance 16.3

Examples 2 to 5
and control insurance Z:; nd

In the center of a reaction vessel like that used in Example I was a 100 W high pressure mercury lamp installed (with 54% of the rays emitted by these holding wavelengths that 38 (K) A not exceeded). The lamp was cooled on all sides with running water. Into the reaction vessel Trichlorosilane and various aromatic compounds were added in a molar ratio of 1: 1. While the chlorine was being passed in in the proportions given in Table 1, the reaction was 5 hours accomplished. The results shown in Table 1 were obtained.

As control tests 2 and 3, the same or similar tests were repeated, with the only one (nt'.Tschied that instead of the 100-W high-pressure mercury lamp a 100 W cylinder lamp used would. The results also shown in Table 1 were obtained.

Type of aromatic
Connections (Λ)

Table I examples

benzene

Chlorobenzene

Toluene diphenyl ether

benzene

Chlorine / ol

1,155 It
3 Discontinued amount of Trichlnrsiian (parts) ... 7HO 542 Discontinued quantity vim Λ (Parts) 54.3 450 Discontinued amount of Chlorine (parts / etd.) Phenyltri- 25th Preserved reaction chlorosilane pnuliikt (B) Chlorine- phenyltri- ehlorsilane Amount of received 2197 Reaction liquid (Parts) 1000 Analysis of the received 30.2 TliisMgkeil (%) 3.4 Trichlorosilane 23.1 25.4 Siliciumelraehlorid. . . 5.3 Not reported A .... 31.4 30.3 Amount of manufactured tem U 11.9 31.2 Substance with high boiling point 7.6 Be ') / \ lclilorid 64 Dent from B opposite Trichloisilane (%) 60

! ■ 'orlsel / unn Examples 542
368
23.1

Tolyltriehlorsilane 940

37.5

3.6

25.4

9.7
5.4

Type of aromatic compounds (A) .

57

393
493

22.5

Phenoxyphenyltri-
chlorosilane

890

19.4

5.0

41.5

28.9

5.2

52

Knnlrollvcriitichi:
1

1355
780
54.3

Phenyltrichlorosilane

2240

21 < j
17.5
24.5

15.9
12.3

23.3

542

450

25th

Chlorophenyltrichlorosilane

992

27.3
15.4
3S.3

14.8
4.2

29.9

Control attempt 4

Similar to that in Example 5, an experiment was carried out in which 0.5% aqueous solution of potassium dichromate instead of water for cooling The high pressure mercury lamp was used, which accounts for about 80% of the total emitted The lamp's rays had wavelengths of 5400 to 5800 Λ and 19% wavelengths that 38OOA did not exceeded. When the reaction was over. the reaction product was purified to give the desired Phenoxyphenyltrichlorosilane occurred only in traces. Only 250 parts of silicon tetrachloride became Ls and recovered 440 parts of diphenyl ether.

Control attempt 5

542 parts of trichlorosilane and 492 parts of nitroben / ol in a molar ratio of I: I were placed in a reaction vessel similar to that used in Example I. Then the light was switched on and at the same time chlorine was passed into the reaction vessel in an amount of 23.3 parts per hour. The reaction was carried out with stirring. Nitrobenzene remained unchanged, and trichlorosilane, among other things, was converted into silicon tetiochloride. If Ikn / .oiri- <> o ftuorid in place of nitrobenzene in an equal

Tafel or similar attempt was used, transformed Trichlorosilane is only found in silicon dioxide.

Examples 6 to 9
and control experiment 6

As in Examples 6 to 9, wind in a reactor corresponding to Example 1 methyldichlorosilane and various aromatic compounds in a molar ratio 1: 1 given, using the light source described i; .i Example I. DicRcaklionwurdc carried out as in Examples 2 to 5. The results shown in Table 2 were obtained.

Another experiment was carried out as control test 6. In this case, all the conditions were the same as in Example 6 with the exception that a 100 W filament lamp was used instead of a 100 W high-pressure mercury lamp. The result is also shown in Table 2 A further experiment was carried out like that given in Example 9, but with the modification that a 100 W incandescent filament was used instead of a 100 W high-pressure low pressure lamp methyldichlorosilane and diphenyl ether reacted.

Hrispiclf

benzene

(lilobenzene toluene

Dinhenvläther

Kiinlriillui Midi

benzene

continuation

Examples

Discontinued amount of

Methyld'chlorosilane (parts)
Discontinued set of A

(Parts)

Discontinued amount of

Chlorine (parts hours)

Frhaltencs reaction

product (B)

Amount of received

Reaction liquid (parts) j
Analysis of the received

Liquid (%)

Methyldichlorosilane

Methyltrichlorosilane

Not responding A

Amount of B produced

Benzyl chloride

Substance with high
boiling point

Yield of B versus
Mclhyldichlorsikm

230 156

is

506 495 575
460

"K

Phenylmethylene-! Chlorophenyl- i Tolmetln I-dichlorosilane | netlnl- i diehlorsilane

diclilorsilane ί

402

28.6 14.2 27.9

6.0 49 0

10.V

37.2 20.1

7.3 23.2 23.5 33.3 12.7 K) S ⁵

42.0 " ¹ p. 7
10.5
29.2
17.7
5.6

P. 3
40.7

403

597

I'henoxN-pheinlin ethyldiehlorosilane

1030

21.6

6.9

4 p. 4

16.0

7.1

37 0

KnnlroHvirsuch 6th

230

156

15th

I'hciiy Imellnldichlorosilane

4OS

20.3

<1.0

12.4

B c i s ρ ι e 1 10,.

This experiment corresponded to that in Example 6 with the modification that chlorine in the bottom of the Reaction vessel was introduced in an amount of 47 parts per hour. The reaction was 5 hours stirred, 435 parts of the product., o obtained from the constituents shown below composed. The yield of methyl methyldichlorosilane versus methyldichlorosilane bcl rug 44.0%.

(ieuichfspnvcnt

Methyldichlorosilane

Metlnliriehlorsilane

benzene

l'henvlmellnldichlorosilane

High boiling point substance.

It should be noted that the reaction in the Testicles of the mixed fluid layer introduced (hlrrmcngc sroß was. so that some of the chlorine from the liquid layer was not absorbed, but Reached the height of the layer, with the cooler one Reaction in a vaporous state caused and the contents of the reaction fold a blackish one (iclb exhibited.

ta example 11

in a reaction vessel as in Example 6,690 parts Mcthyldichloisilan and 4fc8 teiie benzene If Fine loO-W high-pressure Quecksilberlampc were (which was installed. allseilig that it was cooled by running water fi ₅₎ is turned on. At the same time, chlorine was introduced into the bottom of the mixed liquids layer in an amount of 53 parts per hour, and the reaction was carried out for 5 hours. The reaction product obtained showed the following constituents: The yield of methyl methyl dichlorosilane compared with methyl dichlorosilane was 48.0 °.

<'!!' «'• ■ tii ^ privcni

Methyldichlorosilane IS.3

Methyltrichlorosilane I ~. ^ς

Benzene 25.6

Phcnylmethyldichloi -vilan 2 ¹ U

High boiling point substance 9.3

Example 12

460 parts of methyldichlorine in and 312 parts of benzene were placed in a reaction vessel like that used in Example 6, and under Beslrahhini: with a 100 W high-pressure mercury lamp (which was attached so that it was cooled on all sides by running water) de chlorine in the bottom liquid layer was in an amount of 47 "initiated parts prc hour. the reaction was 5 Stundci i ^J irchgeführi while the Reaklionstemperatur be. 4) up to 50" C was maintained. 833 parts of the obtained; The product showed the following constituents. The yield of phentelmethyldichlorosilane versus methyldichlorosilane was 46.4%.

Gc «i ': hlsprivcr

Methyldichlorosilane 11.7

Methyltrichlorosilane 18.2

Benzene 26.5

Phenylmethyldichlorosilane 33.5

High boiling point substance 10.1

109 684/31 '

1982

Control process 7

This experiment was carried out similar to that in Example 12, using 0.5 vol. Aqueous solution of potassium dichromate was used instead of water to cool the high pressure mercury lamp. Through this Approximately 80% of the total rays emitted by the lamp had wavelengths of 54CO up to 5800 Λ nuf and 19% of it wavelengths, due 3800 Λ niciii exceeded. When the reaction ends the product obtained had the following components. The yield of methyl methyl dichlorosilane compared to methyldichlorosilane was at the low value of 11.6%. The amount of The metlyltrichlorosilane which had also accrued was very grumpy.

(iewichlsprn / eni

Methyldichlorosilane 1.3

Methyltrichlorosilane 48. (V

Hen / Ol 28.5

(icuichtspro / cni

Phenylmethyldichlorosilane 10.5

High boiling point substance 11.7

Examples 13-15 and controls 8 to 10

In the middle of a reaction vessel with a A reflux condenser, a thermometer and a gas pipe, a light source was installed which was cooled on all sides. The cooling method was taken from the group given in Table 3 selected. 403 parts of methyldichlorosilane and 273 parts of benzene were added to the reaction vessel.

After mixing, it was stirred. The atmosphere inside the reaction vessel was replaced by nitrogen replaced. While the light source was on, chlorine gas was mixed into the bottom of the liquid layer initiated at a rate of 21.6 parts per hour. The first reaction was 5 hours accomplished. The results given in Table 3 were obtained.

Plate 3

Light source

cool melhode.

Share of rays with
Wavelengths below
3H (K) Λ. ^

Received amount of
Reaction liquid
(Parts)

Anal eggs received
Liquid (%)
Methyldichlorosilane ....
Methyltrichlorosilane ....

benzene

Phenylmethyldichlorosilane

Substance with high
boiling point

Yield of phenylmethyldichlorosilane
versus methyldichlorosilane

K) -W low pressure mercury lamp

Air cooling

692

28.7 10.5

28.4

25.2 7.2

51.1

Examples

100 W high pressure ock silver lamp

Water cooling control searchc

54 690

28.6 12.1 28.4

24.9 6.0

50.3 15

100 W high pressure mercury lamp

cooling
with aqueous solution of
NiCl ₂ 6H, O |
1 kg I.

36
690

28.6
14.5
28. i

22.4
6.1

45.3

100 W high pressure mercury lamp

cooling
with aqueous solution of
saturated CuSO ₄
(25 C)

27
696

28.4
27.6
28.1

10.0
5.9

20.3

I (X) -W high pressure mercury lamp

Cooling with an aqueous solution of 0.5% K ₂ Cr ₂ O ₇

19 703

28.1 34.5 27.8

6.1 3.5

12.6

II)

100 W electric filament lamp

Water cooling

0.5

7 (M

28.0 34.7

27.8

5.7 3.8

11.8

Claims (1)

Claim: A process for preparing aryl chlorosilanes by reacting Hydridochlorsilanen with aromatic hydrocarbons under irradiation, characterized in that trichlorosilane or methyldichlorosilane mn benzo! or an alkyl, halogen or phenoxy benzene is irradiated in the presence of chlorine with a light which has at least 30% of its radiation wavelengths which do not exceed 3800 Λ. 1982