SU486014A1 - The method of obtaining 1,2-epoxy-3/9 "carbazolyl / -propane or its halo derivatives - Google Patents

Description

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The invention relates to the field of obtaining compounds of the carbazole series, which can serve as raw materials for the synthesis of polymers, intermediate products for the synthesis of physiologically active substances, additives to epoxy resins, modifying and stabilizing agents for elastic masses, rubbers and rubbers.

A known method for producing 1,2-enoxy-3- (9carbazolyl) propane in two stages. In the first, by fusing carbazole with potassium hydroxide, potassium-carbazole is obtained, which in the second stage is reacted with eichlorohydrin in benzene, and the reaction product is isolated by evaporation of the benzene solution, followed by recrystallization of the residue from alcohol. The yield is small and amounts to only 24% of the theoretical, calculated for carbazole. The duration of the process is 16-21 hours.

The disadvantages of this known method are: the two-stage process, the impossibility of reacting unstable carbazoles when fusing with alkalis (for example, carbazols that are chlorine-substituted in the core) are fused with alkalis under alkaline with chlorine cleavage, the long duration of the process and low yield. The disadvantages include also the relatively painful consumption of ethylorgans; 1a - up to about mol-on-m. P) carbazole.

In order to eliminate these isoethetics, a new method for the synthesis of 1,2-epoxy-3- (9-carbazolyl) propanes is proposed.

According to the invention, the goal is achieved by the simultaneous action of I.a. carbazole (or its derivatives substituted for) eichlorohydrin and alkali in such organic solvents, which contribute to the ionization of carbazole but acids.

The facilitation of the ionization of carbazole or eio substituted in the above-mentioned organic solvents leads to the appearance of the anion of carbazole, which is much more reactive with respect to eichlorohydrin than carbazole or potassium-carbazole itself in inert1 x benzene tin solvents. This leads to an increase in the speed of the process and its development under mild conditions. The latter allows to introduce into the reaction also chlorocarbazoles, which:: e under these conditions, neither tarring nor reaction with chlorine cleavage is exposed. Thus, according to the invention, both a reduction in the duration of the process and an extension of the applicability of the process to chlorine substituents in carbazoles is achieved. At the same time, the yield of the target .enoctct carbazole derivative rises.

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According to the invention, the most suitable solvents are ketones (acetone, methyl ethyl ketone), ethers (dioxane, diethylene glycol dimethyl ether, tetrahydrofuran), dimethylformamide and dimethyl sulfoxide. The temperature regime can vary from 15 ° C to the boiling point, although it is usually sufficient to maintain the temperature from 20 to 60 ° C. The duration of the process can also vary from 2 to 10 hours, while maintaining the above-mentioned benefits of the proposed method.

Essential for suppressing side reactions and for obtaining higher yields than in the known method is the need to reduce the excess of epilchlorohydrin to no less than 0.75 mol per mole of carbazole in relation to the theoretically necessary.

As alkali can be used as caustic soda, and caustic potassium with approximately the same results. The amount of alkali should be sufficient to ensure the ionization of carbazole or its derivative until all the “arbazole” has reacted. Control over alkali consumption during the reaction can be carried out by known methods. The alkali can be introduced into the reaction mixture in portions, and completely in the required amount. Moving the reaction mixture slightly increases the speed of the process, but is not necessary.

Isolation of the target product and its purification are performed by known methods.

Example. To 50 g of carbazole in 500 ml of acetone, potassium hydroxide is added in a ratio of 3 mol per mol of carbazole and epichlorohydrin. In a ratio of 3 mol per mol of carbazole. The mixture is stirred under reflux at 50 ° C until the carbazole disappears from the reaction mixture, as judged by

results of thin layer chromatography, and additionally continue the process for another 1 hour. The overall duration of the process, depending in a small degree on the mode of movement and the degree of grinding of the alkali, is at 3–5 ratios of reagents for 3-5 hours. At the end of the process, the reaction mixture is poured into WATER, allowed to stand, the aqueous layer is sent to regenerate the solvent, and the residue is washed with water until neutral and purified by vacuum distillation, yielding 73% of theoretical 1.2 epoxy-3 as a distillate - (9-Carbazolyl) -ProPro. The pure substance melts at 108-109 ° C.

Found,%: C 81.35, H 5.76; N 6.27. Epoxy number 19,10 ± 0,5.

Calculated%: C 80.9; H 5.84; N 6.29. Epoxy number is 19.28.

Under the same conditions, from 3,6-dichlorocarbazole, the corresponding 9-propenoxide-3,6 dichlorocarbazole is obtained with a yield of about 60% of theoretical with a melting point of mp. 132-134 ° C, epoxy number of 14.6% (calculated epoxy number of 14.7%).

Subject invention

Claims (2)

1. A method for producing 1,2-epoxy-3- (9-: carbazolyl) -propane or is halide derivatives based on carbazole or its derivatives, caustic potash and epichlorohydrin, characterized in that, in order to simplify the process and increase the yield, carbazole or its derivative is subjected to interaction with epichlorohydrin in the presence of caustic alkalis in the medium of an organic solvent with the following extraction of the target product by known methods. 2. A method according to claim 1, characterized in that ketones, ethers, dimethylformamide, dimethyl sulfoxide are used as the organic solvent.