PL169333B1 - Reactive carbazole dyes and method of obtaining them - Google Patents

Abstract

New carbazole azo dyestuffs (I) are substd. by a 2,3-epoxypropyl gp. in the 9-position. (I) are prepd. by (a) reacting carbazole (II) with epichlorohydrin (III) in alkaline medium in the presence of a quat. ammonium salt, pref. triethylbenzylammonium chloride (IV) as catalyst at 0 to 65 deg.C, giving 9-(2,3--epoxypropyl)-carbazole (V); and (b) coupling (V) with a substd. aryldiazonium ion in a mixt. contg. an organic solvent (pref. an ether, esp. THF), water and a strong acid at -5 to 10 deg.C. USE/ADVANTAGE - (I) are used for dyeing natural and synthetic fibres, esp. wool, polyamide and polyester fibres, PVC and epoxide resins (claimed). They are reactive, have good coloristic properties and give fast dyeing.

Description

The subject of the invention is a process for the preparation of new reactive carbazole dyes.

The carbazole system is found in many industrial-scale dyes. The carbazole moiety is characteristic of many vat and direct dyes. It is formed during the cyclization of appropriate dye intermediates, which is described in detail in the monographs of R. Chrząszcz, J. Pielichowski, J. Polaczek and R. Popielarz, "Carbazole dyes", published by the Cracow University of Technology (Scientific Journal No. 2, Issue 17, 1986. ). Dyes obtained on the basis of carbazole as a starting material are also known. These include, in particular, hydrone blue, dioxazine violet and carbazole dyes, known inter alia from patent specification 163,595.

The synthesis of carbazole dyes is based on the use of carbazole as an active or passive ingredient. In the first case, it is required to obtain the corresponding carbazole amine derivative, which can then be coupled after diazotization with conventional passive components. Some carbazole derivatives (hydroxy- and sulfocarbazoles, hydroxycarboxycarbazole acids and their amides) are used in the synthesis of dyes as passive components. It is also possible to directly couple carbazole and its 9-alkyl derivatives with diazonium chlorides. Dyes obtained in these known methods, however, do not have the nature of reactive dyes, which significantly limits their applicability, especially for dyeing synthetic and natural fibers and polymers.

During the conducted research, it was unexpectedly found that new carbazole dyes, in which the hydrogen atom at the nitrogen atom of the pyrrole ring in the carbazole system had been substituted with a 2,3-epoxypropyl group, are characterized by chemical reactivity during the dyeing process of fibers, especially polyamide, polyester and wool fibers. and also during the process of dyeing polymers.

New carbazole dyes of general formula A in which Ar is a phenyl or naphthyl group, optionally substituted in the ortho, meta or para position with a halogen atom or

A nitro group, or a 9-ethylcarbazole group, is prepared by coupling 9- (2,3-epoxypropyl) carbazole with diazonium chlorides used in known processes for the production of azo dyes, containing the above-mentioned groups in the molecule. The reaction is shown in Fig. 1.

This coupling according to the invention is particularly preferably carried out directly in the reaction mixture obtained after the diazotization of the corresponding aromatic amines in a mixture of water and an organic solvent, preferably tetrahydrofuran, in the presence of strong acids, at a temperature of -5 to + 10 ° C for 1-4 hours. and at room temperature for a further 1-10 hours. The 9- (2,3-epoxypropyl) carbazole used in the coupling reaction according to the invention is prepared by the condensation of carbazole with propylene epichlorohydrin in an alkaline medium in the presence of quaternary ammonium catalysts, especially triethylbenzylammonium chloride, at a temperature of 0-50 ° C.

The properties of the new dyes obtained by the method according to the invention and their production by the method according to the invention are illustrated by the following non-limiting examples.

Example I. a) Synthesis of 9- (2,3-epoxypropyl) carbazole (Fig. 2a). 5 g (0.03 mol) of carbazole, 10 ml of water, 1 g of triethylbenzyl ammonium chloride (TEBA), and a mixture of 10 ml of propylene epichlorohydrin and 10 ml of hexane were placed in a three-necked flask equipped with a reflux condenser, a thermometer and a stirrer. Then, while vigorously stirring, 20 ml of 45% NaOH solution was added dropwise, not exceeding the temperature of 50 ° C. After all epichlorohydrin had been added dropwise, the mixture was stirred for a further 2 hours. The contents of the flask were then poured into water, and after separating the organic layer, the precipitate of crude 9- (2,3-epoxypropyl) carbazole was filtered off from the aqueous phase. 5.6 g of crude product was obtained, which was crystallized from the system methanol: acetone = 10: 1. The product was obtained with a melting point of 107 ° C with a yield of 70%. 1 H-NMR spectrum of the product obtained: 8H (carbazole system) 8.2-7.0 ppm; 2H (CH2 group) 4.8-4.2 ppm; 1H - 3.4-3.2 ppm; 2H (oxirane system) 2.9-2.4 ppm.

b) Coupling of 9- (2,3-epoxypropyl) carbazole with p-bromo-phenyldiazonium chloride (Fig. 2b). 0.7 ml of concentrated hydrochloric acid and 3 ml of water were added to 0.39 g (0.0022 mol) of p-bromoaniline. It was carefully warmed up and cooled to 0 ° C. 0.17 g of sodium nitrite in 1.5 ml of water was then slowly added while keeping the temperature below 5 ° C. After diazotization was complete, the mixture was stirred for 20 minutes and neutralized with sodium hydroxide solution to pH = 6. Then 0.5 g (0.022 mol) of 9- (2,3-epoxypropyl) carbazole in 10 ml of tetrahydrofuran was added. The mixture was stirred for 2 hours at 0-5 ° C and then raised to room temperature for 4 hours. After evaporation of the solvent, it was quenched with methylene chloride, the organic layer was washed with water and the solvent was removed therefrom. 0.65 g of a homogeneous (HPLC) substance of a red-brown color, the solution of which in tetrahydrofuran shows an orange color, was obtained. The maximum ultraviolet absorption of the dye obtained is at 470 nm (FIG. 6, curve 1). The dye is useful for dyeing polyamide and wool fibers.

Example II. Coupling of 9- (2,3-epoxypropyl) carbazole with naphthylazonium chloride (Figure 3). The coupling was carried out in the same way as in Example 1, taking 0.5 g of 9- (2,3-epoxypropyl) carbazole (0.022 mol) prepared as described in Example 1a for the reaction, 0.33 g of 1-naphthylamine (0.022 mol), 0, 6 ml of concentrated hydrochloric acid and 0.17 g of sodium nitrite (0.025 mol). 0.6 g of a homogeneous (HPLC) dye solid was obtained, the tetrahydrofuran solution of which showed a red-orange color. The maximum ultraviolet absorption of the dye obtained is at 465 nm (FIG. 6, curve 2). The dye is useful for dyeing polyvinyl chloride.

Example III. Coupling of 9- (2,3-epoxypropyl) carbazole with p-nitrophenylazonium chloride (Figure 4). The coupling was carried out in the same way as in Example 1, taking 0.5 g of 9- (2,3-epoxypropyl) carbazole (0.022 mol), prepared as described in Example 1a, 0.31 g of p-nitroaniline (0.022 mol), 0, 7 ml of concentrated hydrochloric acid and 0.17 g of sodium nitrite (0.025 mol). The reaction was carried out by using chloride as the organic phase

169 333 methylene (20 ml) (with added mersolane as emulsifying agent) or in a THF-water medium. In both cases, an orange-yellow homogeneous (HPLC) diazo derivative was obtained, mp 40-44 ° C. The resulting dye solution showed a yellow-orange color. The maximum absorption in ultraviolet is at 425 nm (Fig. 6, curve 3). The dye is useful for dyeing epoxy resins and polyester fibers.

Example IV. Coupling of 9- (2,3-epoxypropyl) carbazole with 9-ethyl-carbazole-3-diazonium chloride (Figure 5). 20 g of 9-ethylcarbazole was dissolved in 230 ml of glacial acetic acid at room temperature. Thereafter, 4.7 ml of concentrated nitric acid (d = 1.5 g / ml) were added dropwise to the solution over 1.5 hours. The mixture was further stirred for 2 hours. The precipitated solid was filtered off and washed to neutral with water. 17.5 g of 9-ethyl-3-nitrocarbazole are obtained. Then 7.26 g of 9-ethyl-3-nitrocarbazole were dissolved in 125 ml of glacial acetic acid at 95 ° C, and 7.5 g of iron and 1 ml of water were added to the obtained solution. The mixture was kept, stirring vigorously, in a boiling water bath for 20 minutes. The solution was then cooled and 60 ml of concentrated hydrochloric acid were added. After filtration, the filtrate was poured into 300 ml of a 15% hydrochloric acid solution. To isolate the 9-ethyl-3-aminocarbazole hydrochloride, the solution was concentrated to 200 ml and cooled. After cooling, 2.8 g of the hydrochloride were filtered off. The coupling was carried out in the same way as in Example 1, using 0.5 g of 9- (2,3-epoxypropyl) carbazole (0.022 mol) prepared in the manner described in Example 1a, 0.55 g of 9-ethyl-3-aminocarbazole hydrochloride (0.022 mol), 0.7 ml of concentrated hydrochloric acid and 0.17 g of sodium nitrite (0.025 mol). 0.85 g of brown nitrogen derivative was obtained, the solution of which in tetrahydrofuran showed a red color. In the ultraviolet absorption curve (Fig. 6, curve 4), no distinct maximum was observed.

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Fig. 6: UV absorption spectra of the coupling products of 9- (1,2-epoxypropyl) -carbazole with diazonium chlorides obtained by tearing against the following amines:

- p-bromoaniline

- l-naphthylamine

- p-nitroaniline

- 9-ethyl-3-aminocarbazole.

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Fig. 4

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Fig. 1

Pattern A

Fig. 2a

Fig. 2b

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Claims (4)

Patent claims A process for the preparation of new reactive carbazole dyes of general formula A, in which Ar is a phenyl or naphthyl group, optionally substituted in the ortho, meta or para position with a halogen atom or a nitro group, or a 9-ethylcarbazole group, characterized in that 9- ( 2,3-epoxypropyl) carbazole is coupled as an inactive component with diazonium chlorides containing a phenyl or naphthyl group, optionally substituted in the position ortho, meta or para to the diazonium group with a halogen atom or nitro group, or a 9-ethyl carbazole group. 2. The method according to p. The process of claim 1, wherein the coupling is performed immediately after the diazotization of aromatic amines, in mixed solvents containing water, in the presence of strong acids at temperatures below 10 ° C for 1-4 hours, and for a further 1-10 hours at room temperature. 3. The method according to p. The process of claim 1, characterized in that the inactive 9- (2,3-epoxypropyl) carbazole is prepared by condensation of carbazole with epichlorohycidinpropylene in an alkaline medium in the presence of ammonium salts at a temperature of 0-50 ° C. 4. The method according to p. The process of claim 3, characterized in that triethylbenzylammonium chloride is used as the quaternary ammonium salt.