DE1950422A1 - Process for initiating the carbazolation reaction of anthrimides - Google Patents

Description

Vyzkumny ustav organickych syntez, Pardubice-Rybitvi

(Czechoslovakia)

Method of initiating the carbazolation reaction of

Anthrimids

The invention relates to an initiation method of Carbazolation reaction of anthrimides due to the action of titanium tetrahalloride in the medium of organic ones solvents.

The purpose of the invention is to create a process for initiating the carbazolation reaction of anthrimides on the basis of the action of titanium tetrachloride by adding substances which easily release organic radicals.

By the carbazolation of anthrimide », i.e. duroh the

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Denydrierungscyclisierung of secondary amines der Anthraquinones, which are associated with the formation of five- or is connected to six-membered nitrogen heterocycles, derivatives of diphthaloyl carbazoles, which form an important class of vat dyes, are produced. Titanium tetrachloride is one of the agents used for successful carbazolation. That US patent Mr. 2,416,931 describes the use of titanium tetrachloride for the carbazolation of the most used anthrimides.

The action of these substances on the anthrimides first created the complex compounds of diphthaloyl carbazole derivatives made with the halides used that make up the actual dyes have been isolated by various methods.

The complex compounds formed primarily produced by the heating of Anthrimidsuspension in excess of titanium tetrachloride or, advantageously, in the titanium tetra-chloride solution in an inert solvent (mostly benzene halogen derivatives) at temperatures of 100-20O ⁰ C. The actual execution of the reaction; was realized in different ways, but the i

the common trait of the reaction was its characteristic quick "start". The carbazolation does not proceed slowly in the course of heating, but only after a certain temperature has been reached. Its' height depends essentially on the Anthrimidkonetitution, it is not a precisely defined value and varies in Leaper atur int ervall of + 5 to 20 ⁰ O

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close to the mean value. As soon as the reaction "kicks in", it usually runs very quickly and practically uncontrolled, which is noticeable by a stormy escape of hydrogen chloride (Due to the formation of a new bond, two hydrogen atoms are released, those with the chlorine atoms of titanium tetrachloride react). The reliable removal of hydrogen chloride is practical Operation poses a major technological problem. It is possible to practically solve this problem, for example, by the Gradual dosing of one component (anthrimide, titanium tetrachloride) to dissolve into the other. Is suggested also a continuous synthesis.

The regulated initiation of the reaction by using the autocatalytic action of the end product, which was recommended by the authors of the above-mentioned American patent, turned out to be a thorough one Re-examination as negative.

An extensive study of this type of carbazolation reaction has now made the earlier conjectures some authors confirm that it is a radical reaction. This knowledge can be used to favorable effect of the "start-up" of the carbazolation exploit. It can be initiated with substances that release organic radicals, e.g. Derivatives of organic peroxides (methylcyclohexanone peroxide, Methyl ethyl ketone peroxide, di-tert. Butyl peroxide, tert. Buty! Hydroperoxide, tert. Butyl cumyl peroxide, tert. Butyl perbenzoate etc.) or with the easily cleavable ones

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Azo compounds. The initiators can be decomposed using all customary methods best with the warming to an appropriate. Temperature. If it is carried out in such a way that the organic radicals in the reaction mixture under the conditions among which there is even the cyclization of anthrimides can appear, the reaction begins to run momentarily. A great advantage is that that by this initiation of carbazole one already

fe at temperatures 10 to 3O ⁰ O lower than in the reaction initiated by mere heating. This achieves some beneficial aspects. The reaction proceeds more slowly and the hydrogen chloride formed is therefore easier to remove, especially in those cases (1,1 ', 4,1 "- trianthrimide) where the reaction takes place in the vicinity of the boiling point of the organic solvent forming the reaction medium itself has the consequence of lowering the possibility of undesired secondary reactions, possibly decomposition reactions, which on the one hand deteriorate the quality and on the other hand lower the yield of the desired products by 5 to 10 -6.

W! Fights recently, it is also the fact that as a certain level of uncertainty is completely eliminated in controlling the reaction beginning.

Both unsubstituted materials can be used as starting materials Mono- and polyanthrimides (e.g. 1,1-, 1,2-dianthrimide, 1.1 ', 4.1 "-, 1.1', 5.1" -trianthrimide, 1.1 ', 4.1 "-, 5.1"', 8.1 "" - pentaanthrimide), as also their substitutions derivatives (e.g. alkyl, alkoxy, halogen, acylamino, etc.) can be used.

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The actual implementation of the reaction can be accomplished in various ways. The mixture of Anthrimides, titanium tetrachloride and inert organic solvent are heated to the appropriate temperature and the solution and the solution or suspension of initiator, preferably in the same organic solvent, admitted. The temperature is maintained at the same level until the reaction has ended and the Suspension of the formed complex compound of dye with titanium chloride is processed by the usual methods. (US patent Mr. 2,416,931, Czechoslovak patent Mr. 123,732).

Advantageously, only part of one of the components, the carbazolation, can be placed in the reaction vessel start after heating by adding initiator and then adding this component continue up to the appropriate amount. It is not necessary to raise the temperature because the The reaction goes well on the one hand due to the action of the initiator, on the other hand with regard to the autocatalytic influence of molecular radicals of the actual Dye. In the carbazolation carried out in a continuous manner, one can use the initiators on the one hand to "ignite the reactor, on the other hand to use them to accelerate them.

The initiator can either be added to the reaction mixture be added once or in stages, so that the action of the resulting radicals is optimal · The corresponding amount is in the range from 0.5-2OjC (Ge

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weight percent) of the anthrimide used. The choice of initiator depends on the reaction temperature. It is required that it forms radicals sufficiently quickly in the corresponding temperature range, but not all at once. This requirement can also be influenced to some extent by the type of initiator metering. The temperature to which the mixture is to be heated prior to the addition of initiator is in the range 50-1 80 ⁰ O and depends on the constitution of the Anthrimides used. For example Ι'-Dianthrimid sufficient for Ι, about 60 to 70 ⁰ C, for 1,1 ', 5, l "-Trianthrimid 90 to 11O ⁰ C for 1.1 *, 4.1" - is the Trianthrimid corresponding temperature 130 to HO ⁰ C among others

The work process is explained in more detail using the following examples: (The quantities are given in parts by weight)

example 1

A mixture of 8.6 parts of Ι, Ι'-dianthrimide, 7.6 parts of titanium tetrachloride and 500 parts of benzene is heated ^{to 70 0} O and at this temperature for 1 minute the solution of 0.4 part of di-tert-butyl peroxide in 5 Parts of benzene are added. After completion of the reaction, which is characterized by the formation of hydrogen chloride, it is stirred for half an hour at 7O ⁰ C, the suspension was filtered, washed with benzene and the paste dried. The complex compound is ale black powder, from which 8.0-8.5 parts of 1,2,7,8-diphthaloylcarbazole are isolated using known methods.

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Example 2

19.5 parts of 1,1 ', 4, l "-Trianthrimid, 17.1 parts of titanium tetrachloride and 230 parts of o-dichlorobenzene are heated to 14O ⁰ C, to the suspension, the solution of 1 part in 10 parts Methylcyklohexanonperoxid for 10 minutes o-Dichlorobenzene is added. A rapid reaction occurs immediately, after it has ended, the mixture is ^{heated for a further 1/4 hour to 140 °} C. The suspension is filtered off with suction, the paste is washed with o-dichlorobenzene and dried Complex compound from which the dyestuff known under the trade name Ostanthrenbraun BR is isolated using the known methods The yields of dyestuff are about 55% higher than when the reaction is carried out without the use of initiator.

Example 3

In 150 parts of o-dichlorobenzene, 17.1 parts of titanium tetrachloride and 5 parts of 1,1 'are, 4,1''- Trianthrimid added, the suspension is heated to 140 ⁰ C and at the same time the suspension of 1 part of 2,2'-azo -isobutyronitrile in 10 parts of o-dichlorobenzene was added. When the cyclization reaction is complete, the suspension of 14.5 parts of 1,1 ', 4,1' -Trianthrimid is added in 80 parts of o-dichlorobenzene, is such that the temperature constant kept at 140 ⁰ C,! Times the finished dosage if the heating is continued for 1/4 hour, the suspension is ^{cooled to about 100 °} C. and o-dichlorobenzene is distilled off under reduced pressure. The same yield of complex compound and dye as in Example 2 is obtained.

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Claims (1)

Claim: Method of initiation of the carbazolation reaction of anthrimides through the action of titanium tetrachloride in the medium of organic solvents, characterized, that to the mixture of reaction components heated to the temperature of 50 to 180 ⁰ C, organic radicals easily releasing substances, advantageously organic peroxides or unstable azo compounds, in which from 0.5 to 20 $ (percent by weight) of the anthrimide used are added 00981 7 / UOO