DE2036174A1 - Perchloro-vinylaromatics prodn - by two -stage chlorination of methyl-alkylaromatics - Google Patents

Abstract

Perchloro-vinylaromatics, plant protection agent intermediates, agents for flameproofing of plastics, biocides, fungicides and herbicides, are prepd. by treating a cpd. of formula: (R)o- -(alkyl)n (where Ar is a 6-membered aromatic residue in which 3 CH-gps. can be replaced by N and which can be used to a benzene ring; R=CN; Alkyl= Et or iPr; o=0-3, n= 1-3, p= 0-2) with excess Cl2 at 20-200 degrees C in the liquid phase, and then with more Cl2 in the gas phase at 300-500 degrees C.

Description

Perchlor-vinyl aromatics The invention relates to perchlor-vinyl aromatics and a method for their manufacture.

It is known (Real. Phys. Chim. Madrid 57B, 393 (1961)) that in a fiery reaction with the poorly accessible perchlorotoluene among others Products in low yield also the perchlorostyrene can be obtained. This However, the method is not suitable for the preparation of larger quantities of the compound.

It has been found that perchlorinated vinyl aromatics are obtained when compounds of the general formula where Ar is a 6-membered aromatic radical in which up to 3 CH groups can be replaced by nitrogen atoms and the aromatic or heterocyclic radical can still be fused to a benzene ring, alkyl is an ethyl or isopropyl radical, R stands for a nitrile group, 0 0, 1, 2 or 3, n 1, 2 or 3 and p 0, 1 or 2 in the temperature range from 20-2000C in the liquid phase until the exothermic reaction has subsided with excess chlorine and that reaction mixture formed is then reacted in the gas phase in the temperature range of 300-5000C with further chlorine until complete chlorination.

In the gas phase is preferred in the temperature range of 330 -4500C, In particular, however, 360-410OC worked. The preferred workspace in the The liquid phase is 90 - 1700C.

For the implementation of the method according to the invention, it is worthwhile Proven to be useful to work in the presence of catalysts. Exemplary silicon dioxide and pumice, which are impregnated with CuC12, may be mentioned. Particularly However, the usual activated carbons, such as, for example, are preferred as the catalyst in Ullmann's Encyclopedia of Industrial Chemistry, Volume 9, page 806 are described.

The amount of catalyst is such that 3 ml - 20 ml, preferably 4.5 ml - 12 ml, are available per gram of product introduced hourly in the first stage prechlorinated. The process according to the invention is exemplified by the following The starting compounds used for the process are known or can be obtained by known processes.

Examples include: ethylbenzene, iso-propylbenzene, 3-ethylbenzonitrile, 4-ethylbenzonitrile, 5-ethylisophthalonitrile, 1.3-, 1.4-diisopropylbenzene, 1.3. 5-triethylbenzene, 1.3. 5-triisopropylbenzene, 2-, 3-, 4-, ethylpyridine, 2.4-, 2.5-, 2.6-, 3.5-diethyl pyridine, 2-methyl-5-ethyl-pyridine, 2,6-dimethyl-4-ethyl pyridine, 2-cyano-4-ethyl-pyridine, 4-cyano-2-ethyl-pyridine, 2-, 4-, 5-ethyl-pyrimidine, 2-methyl-β5-isopropyl-pyrazine, 2-methyl-6-isopropyl-pyrazine, 2-ethylpyrazine, 2-isopropyl-pyrazine, Mono-, Di-, triethyl-sym. -triazine, 1-, 2-ethylnaphthalene, 1-, 2-isopropylnaphthalene, diethylnaphthalene, Diisopropylnaphthalene, 1-cyano-3-ethyl-naphthalene, 1-cyano-4-ethyl-naphthalene, 2-, 3-, 4-, 5-, 6-, 7-, 8-ethylquinoline, isopropylquinoline, diethylquinoline, 1-, 3-, 4-, '5.- ,. 6-, 7, 8-ethylisoquinoline, diethylisoquinoline, 2-, 5-,, 6-'ethylquinoxaline, Diethyl quinoxaline.

If heterocyclic starting compounds are used for the process, so can of course also their hydrohalides, preferably the hydrochlorides can be used.

In comparison with chlorination in the liquid phase, there is a special one Advantage of the present process in the formation of uniform products that can be isolated by distillation from the crude mixtures in good yield. Because the reaction is exothermic, it is convenient to use them in one.

vertical pipe (flow pipe) and the resulting Heat from a circulating bath liquid, a circulating gas (CO2, N2) or else can also be removed with a fluidized bed made of corundum.

The dilution of the reaction mixture is also necessary to dissipate heat Nitrogen, hydrogen chloride, carbon tetrachloride or tetrachloropyrimidine of Advantage.

The word flow pipe is to be interpreted broadly in the present ball. It can be tubular reaction chambers of various designs, e.g .: rectilinear, spiral or curved, in which the implementation with different Speed can take place; This also includes fluidized bed-like arrangements. The flow rate depends on the temperature and dilution of the reaction mixture addicted.

Both in the liquid and in the gas phase of the process should the chlorine with an excess of 50 mol%, better still 100 mol * over the theoretical required amount must be available. Too little chlorine in the starting mixture requires incomplete chlorination combined with rapid inactivation of the catalyst.

In addition, the isolation of the desired connection is made difficult for the raw mixes. Large excesses of chlorine are not necessary for the reaction disadvantageous.

For 'the life of the catalyst and a good yield it is It is advantageous to use the alkyl aromatics or alkyl heteroaromatics in a liquid-phase chlorination to chlorinate under UV light and these partially chlorinated products under V evaporation in Chlorine stream in addition to inert dilution (HCl gas, N2, CCl4 gas) over the catalyst respectively.

Description of the apparatus for gas-phase chlorination: A vertical one electrically heated glass tube of 250 mm length and 25 mm diameter filled with Quartz splinters, the lower exit of which is designed as a siphon and for continuous use Discharge of non-evaporable parts is used, has two inlet nozzles at the top Part for the supply of chlorine gas and partially chlorinated liquid substance mixtures and a lateral outlet connection for the discharge of vaporous reaction mixtures.

The side exit of the evaporator opens into a vertical one Duran glass tube 300 mm long and 30 mm in diameter, which is covered by a thermally conductive, heatable and coolable metal cylinders surroundvist. To the exit of Reaction tube is connected to a heated receiver with a -setztem cooler. In the template is always held under reflux Ghloloform, the emerging crystal mixture holds in solution and prevents sublimation into the cooler outlet.

The compounds obtainable by the process correspond to the general formula where Ar stands for a 6-membered aromatic radical in which up to 3 CH groups can be replaced by nitrogen atoms and the aromatic or heterocyclic radical can still be fused to a benzene ring, R CN, m 3, 4, 5, 6, 7, n means 1, 2, 3, o 0, 1, 2, 3 and the sum of m + n + o means a maximum of 8.

Compounds preferably obtainable by the process are those in which the sum m + n + o means a maximum of 6.

Of the compounds that can be obtained using the procedure, only known as perchlorostyrene. The new compounds obtainable by the process correspond to the aforementioned general formula, where Ar and R'die above have the meaning mentioned, m is 3, 4, 5, 6, 7, n 1, 2, 3, -o 0, 1, 2, 3, the sum of m + n + o means a maximum of 8, but in the case that Ar is for is a benzene ring and o is the number 0, n is 2 or 3.

The compounds obtainable by the process are valuable intermediates for the production of pesticides and can continue to be used for flame-retardant equipment of plastics are used. In addition, they can also be used directly due to their biocidal properties Effectiveness, for example as fungicides, but especially as herbicides Find use.

Example 1 160 g of 4-ethylpyridine in 200 ml of chloroform-become at 300 C saturated with HCl gas, then chlorine is passed in under UV light The temperature should be 900C for about 1 hour, and 960 g of tetrachloropyrimidine will be produced admitted. Taking into account a constant excess of chlorine in the exhaust gas, the Temperature increased every hour by 10 ° C up to 165 ° C. After a total reaction time After 12 hours, the pre-chlorination is largely complete.

Weight 1357 g.

The above mixture is used for perchlorination in the gas phase with a throughput of 48 g per hour and 107 g per hour of chlorine gas evaporated at 270 ° C and at 4000C in the reaction tube filled with 180 ml of activated carbon (3 mm grain size).

The crude mixture obtained from the gas phase chlorination becomes a fractionated one Subjected to distillation and provides after separation of tetrachloropyrimidine and Pentachloropyridine at bp 0.1 120-125 ° C 280 g of 4-trichlorovinyltetrachloropyridine c) 4 54% d. Th.

Mp 99-1010C (from ethanol).

Example 2 250 g of 2-methyl-5-ethylpyridine and 250 ml of chloroform are used saturated with HCl gas at 300C. Afterward.

a vigorous stream of chlorine develops under vigorous stirring and under ultraviolet light passed through the solution by means of an induction frit and the temperature increased every hour increased by approx. 15 ° C up to 1780C.

The pre-chlorination is complete after about 12 hours and one obtains 708 g of a viscous oil for gas-phase chlorination with 354 g of carbon tetrachloride is diluted.

For perchlorination in the gas phase, 40 g per hour of the above Gemisbh evaporated together with 105 g per hour of chlorine gas at 2700C and at 4000C introduced into the reaction tube filled with 180 ml of activated charcoal (3 mm grain size). Fractional distillation of the crude mixture delivers at bp 0.1 115-1200C 572 g 3-trichlorovinyltetrachloropyridine = 79.7 d. Th.

Mp. 84-860C (from ethanol) Example 3 The pre-chlorination of 3,5-diethylpyridine is carried out analogously to example 2. 525 g of partially chlorinated are obtained from 200 g of diethylpyridine Product which is diluted with 525 g of carbon tetrachloride for gas phase chlorination.

The perchlorination takes place as in Example 2 at a contact temperature from 3400C.

The fractional distillation of the crude mixture yields at bp 0.1 135-140 ° C 470 g of 3,5-bis-trichlorovinyltrichloropyridine 72% of theory Th.

Mp. 125-126 ° C (from ethanol) Example 4 The pre-chlorination of 2-ethylpyridine takes place analogously to Example 2. 340 g of partially chlorinated are obtained from 160 g of 2-thylpyridine Product that is diluted with 340 g of carbon tetrachloride for gas-phase chlorination subsequent Perchlorination is among those given in Example 2 Conditions completed at a contact temperature of 3400C.

The fractional distillation of the crude mixture resulted in bp 0.1 110-115 C to 107 g A = 20.7% 2-trichlorovinyltetrachloropyridine Ep. 66.5-67.5 ° C (from Methanol) Example 5 For the preparation of 5-trichlorovinyl-2,4,6-trichloropyrimidine 5-ethyl-2,4,6-trichloropyrimidine was first produced by the classic process. A mixture of 30 g of 5-ethyltrichloropyrimidine was diluted with tetrachloropyrimidine and 30 g of tetrachloropyrimidine evaporated in the presence of 80 g of chlorine at 2500C and In the course of 2 hours at 4000C over 180 ml of activated carbon (3 mm grain size) passed.

The fractional distillation of the crude mixture resulted in EP10 170-175 332 g of 5-trichlorovinyl-2,4,6-trichloropyrimidine «72, i.e. Thc pp. 73.5-74.5 ° C (from methanol) Example 6 The pre-chlorination of the aromatic aromatics in Examples 6-11 was only carried out in the temperature range between 100-1800C under UV light, whereby the temperature was increased by 160C every hour. The reaction is strong at the beginning exothermic and requires cooling.

The above method gives 520 g of partially chlorinated from 200 g of ethylbenzene Product used for gas phase chlorination with 260 g carbon tetrachloride The mixture thus obtained is diluted at a rate of 48 g evaporated per hour in the presence of 105 g of chlorine per hour at 2700C and at 3700C perchlorinated over 180 ml of activated carbon (3mm grain size).

A crude mixture is obtained from which by fractional distillation at bp10 195-198 ° C = 434 g = 60.5, i.e. Th.

Perchlorostyrene can be obtained.

M.p. 96-970C (from methanol).

Example 7 Under the conditions of Example 6, 200 g of cumene are converted 432 g of partially chlorinated cumene are obtained which, in dilution with 432 g of carbon tetrachloride perchlorinated analogously to Example 6 in the gas phase and then distilled will.

Bp10 195-198 ° C 322 g perchlorostyrene A = 51, i.e. Th.

Example 8 Analogously to Example 6, 200 g of 1,3-diisopropylbenzene are converted 510 g of partially chlorinated product were obtained, which was used for gas-phase chlorination with 900 g of carbon tetrachloride is diluted.

For the perchlorination, 80 g per hour of the above mixture are combined evaporated with 105 g per hour of chlorine at 2900C and at 4000C over 180 ml of activated charcoal (3mm grain size).

After fractional distillation, the raw mixture at bp 0.1 155-1600C = 317 g A = 53.8, 'd. Th.

Obtained 1 .3-bis-trichlorovinyltetrachlorobenzene.

Mp. 136-1380C (from ethanol) Example 9 Among the The conditions of Example 6 are obtained from 122 g of 1,4-diisopropylbenzene, 400 g of partially chlorinated Product which is diluted with 400 g of carbon tetrachloride for gas phase chlorination.

6 The perchlorination proceeds as in Example 8.

The fractional distillation of the crude product yields at bp 0.1 175-180 ° C = 132 g = 37% d. Th. 1.4-bis-trichlorovinyltetrachlorobenzene.

Mp 196-198 ° C.

Example 10 Analogously to Example 6, 200 g of 1,3,5-triisopropylbenzene are converted 490 g of partially chlorinated product obtained, which for the gas phase chlorination with 500 g Carbon tetrachloride and 500 g of tetrachloropyrimidine is diluted.

The above mixture is used for perchlorination at a rate of 76 g per hour in the presence of 105 g per hour of chlorine evaporated at 3200C and at 4000C over 180 ml of activated carbon (3 mm grain size).

Subsequent fractional distillation gives the crude mixture at bp 0.05 178-185 ° C.

324 g 1,3,5-tris-trichlorovinyltrichlorobenzene = sa, d. Th.

Mp. 208-2090C (from chloroform / ethanol 1: 5) Example 11 After the The method described in Example 6 is obtained from 136 g of 4-cyanoethylbenzene, 310 g partially hollowed crystalline product which, when diluted with 310 g of tetrachloropyrimidine to the Gas phase chlorination arrives.

For perchlorination, 45 g per hour of the above mixture are added 71 g per hour of chlorine evaporated at 2500C and at 370 0C over 180 ml of activated charcoal (3 mm grain size).

The product obtained is in a 60 cm electrically heated column distilled at 10 torr to 190 ° C. The remaining residue is at boiling point 0.01 and 130-140 ° C bath temperature sublimates and provides 285 g of # 74% 4-trichlorovinyltetrachlorobenzonitrile.

Mp 123-1240C.

Claims (5)

Claims 1. Process for the preparation of perchlor vinyl aromatics, characterized in that compounds of the general formula are used where Ar is a 6-membered aromatic radical in which up to 3 CH groups can be replaced by nitrogen atoms and the aromatic or heterocyclic radical can still be gelled with a benzene ring, alkyl is an ethyl or isopropyl radical, R o represents a nitrile group 0, 1, 2 or 3 n 1, 2 or 3 and p 0, 1 or 2 means treated with excess chlorine in the temperature range of 20-200 ° C. in the liquid phase until the exothermic reaction subsides and that reaction mixture formed is then reacted in the gas phase in the temperature range of 3000-5000C with further chlorine until complete chlorination. 2. The method according to claim 1, characterized in that one is in the presence of CuCl2 ~ impregnated silicon dioxide or pumice or with activated carbon as a catalyst is working. 3. The method according to claim 1, characterized in that one carries out the reaction in the gas phase in a flow tube at 330 - 4500C. 4. Perchlor-vinyl aromatics of the general formula where Ar stands for a 6-membered aromatic radical in which up to 3-CH groups can be replaced by nitrogen atoms and the aromatic or heterocyclic radical can still be fused to a benzene ring, R stands for CN, m 3, 4, 5, 6, 7, n means 1, 2, 3, 0, 0, 1, 2, 3. 5. Compounds according to claim 4: 4-trichlorovinyltetrachloropyridine 3-Trichlorovinyltetrachloropyridine 3,5-bis - Trichlorovinyltrichloropyridine 2-Trichlorzinyltetrachloropyrldine 5-trichlorovinyl-2,4,6-trichloropyrimidine 1,3-bis-trichlorovinyltetrachlorobenzene 1,4-bis-trichlorovinyltetrachlorobenzene 1.3.5-tris-trichlorovinyltrichlorobenzene 4-trichlorovinyltetrachlorobenzonitrile