RU2793329C1 - Piperazine-substituted derivatives of 5-nitro-4,6-dichlorobenzofuraxan and 4,6-dinitro-5,7-dichlorobenzofuraxan with antibalantidia activity - Google Patents

Abstract

FIELD: organic chemistry.

SUBSTANCE: invention relates to new nitrogen- and oxygen-containing heterocyclic compounds, namely piperazine derivatives of 5-nitro-4,6-dichlorobenzofuraxan and 4,6-dinitro-5,7-dichlorobenzofuraxan (1–7) total formula I, for use in the field of veterinary medicine and medicine.

EFFECT: piperazine-substituted derivatives of 5-nitro-4,6-dichlorobenzofuraxan and 4,6-dinitro-5,7-dichlorobenzofuraxan, having anti-balantidia activity at low concentrations (0.001%) and thermal stability.

1 cl, 2 dwg, 8 ex

Description

The invention relates to the field of organic chemistry, in particular to new nitrogen- and oxygen-containing heterocyclic compounds, namely, to stable piperazine-substituted derivatives of 5-nitro-4,6-dichloro- and 4,6-dinitro-5,7-dichlorobenzofuraxans of general formula I ( 1-7 ), which have high antibalantidia activity at low concentrations (0.001%) and which can be used in the field of veterinary medicine and medicine.

The development of new domestic drugs is now, in connection with the sanctions of the European Union, put by the Russian state into the rank of the main priority areas of socio-economic development and national security of our country. Therefore, in terms of adaptation to new market conditions, the fundamental task of organic, pharmaceutical and medicinal chemistry is the development of new domestic effective drugs with high physiological activity and minimal toxicity. For the successful implementation of the task set by the government, it is necessary to solve issues that are at the intersection of many areas of science - chemistry, physics, biology, veterinary medicine and medicine. However, the absence of a single satisfactory theory linking the chemical structure with biological activity as of the filing date of the application significantly slows down the emergence of new domestic drugs not only in Russia, but throughout the world.

The applicant for the first time obtained compounds of a new class, previously unknown from the prior art, having no analogues in the world and not described in the literature. After the applicant conducted biological tests on live cultures of balantidia in pigs, high encouraging results were obtained. In addition, according to TG-DSC data (thermogravimetry and scanning calorimetry), the claimed compounds are thermally stable when heated to 200°C without decomposition and weight loss and withstand sterilization and autoclaving.

Structural analogues as drugs with antibalantidia activity, from the studied prior art, the applicant has not identified.

Based on the synthesis of the claimed compounds, it is possible to create dosage forms for the prevention and treatment of balantidiasis in pigs, which can be used in medicine.

Balantidiasis is a widespread disease of pigs on agricultural farms, the causative agent of which is the infusoria Balantidium coli , which lives mainly in the large intestine of pigs [https://ru.wikipedia.org/wiki/Balantidiasis]. In addition to pigs, other animals, as well as humans, also suffer from balantidiasis. The disease proceeds with the phenomena of catarrhal colitis or catarrhal-hemorrhagic enterocolitis, accompanied by diarrhea, emaciation, blood is found in the feces. Animals lie, refuse to feed. Weight loss usually continues after treatment. The disease lasts from three weeks to two months, often until complete exhaustion. Diagnosis is based on clinical signs and examination of fecal samples, which show a large number of motile balantidia and cysts.

The tactics of treating balantidiasis include the destruction of the pathogen, the removal of intoxication and the maintenance of the general condition of the animal's body. An analysis of the prior art by the Applicant has shown that a number of drugs are known for the treatment of balantidiasis.

Thus, the invention is known according to patent RU No. 2032415 "Method for the prevention and treatment of balantidiasis of pigs", the essence is a method for the prevention and treatment of balantidiasis of pigs, including giving drinking to piglets before weaning from the sow of biologically active substances, characterized in that the dacha of biologically active substances is carried out for three days before weaning from the sow 2 times a day, and the biologically active substance at a dose of 0.3 0.5 g / kg of animal weight is dissolved in 20 30 ml of distilled water and given together with Trichopolum at a dose of 0.2 0.5 g per head. The method according to claim 1, characterized in that as a biologically active substance, a preparation of plant origin is used, including a plant extract, for example alfalfa hay, containing soluble metal salts, mg/kg of plant mass: Mo 8.0; Ba 10.0; Rv 20.0; V 1.0; Cz 0.5; Zn 200.0; Fe 300.0; Sn 40.0.

In addition, from the description of a well-known invention, it was revealed that the following are usually used to treat balantidiasis:

orasol at a dose: animals 2-3 months. 0.1-0.2; 3-4 months 0.2-0.3; 4-8 months 0.3-0.4; 8-12 months, 0.4-0.5; older than 12 months 0.5-0.7;

Tilan is prescribed at a dose of 0.00125 g/kg 2 times a day for three days in a row, after a three-day break, the course of treatment is repeated. The drug is mixed in water for 20 minutes, and then mixed with food;

metronidazole is given to piglets at a dose of 0.25 g 2 times a day for three days in a row; after 3-7 days repeat 2-3 times;

vetdipasfen for the treatment of piglets up to 30 days is used at a dose of 0.125 g from 31 days to 60 days 0.25 g, from 61 to 120 days 0.375 g and over 120 days 0.725 g daily 1 time per day for three days in a row;

furazolidone is prescribed at a dose of 0.01 g/kg 3 times a day for 3-5 days;

iodinol is recommended for 4-6 month old piglets, 20-25 ml per dose 2 times a day for 7-10 days with a small portion of feed;

The disadvantage of the known means for the treatment of balantidiasis is:

- the development of high resistance, since long-term treatment with these drugs for many years causes parasites to become addicted to it;

- have a high cost.

The claimed compounds from the studied prior art have not been identified.

The technical result of the claimed technical solution is the expansion of the arsenal of funds for this purpose by creating compounds of a new generation - piperazine-substituted derivatives of 5-nitro-4,6-dichlorobenzofuraxan and 4,6-dinitro-5,7-dichlorobenzofuraxan ( 1-7 ) of general formula I , having antibalantidia activity at low concentrations (0.001%) and thermal stability - up to 180-200°C according to the TG-DSC method.

Moreover, the claimed compounds have a low cost.

The essence of the claimed technical solution are piperazine-substituted derivatives of 5-nitro-4,6-dichlorobenzofuraxan and 4,6-dinitro-5,7-dichlorobenzofuraxan ( 1-7 ) of general formula I.

Piperazine-substituted derivatives of 5-nitro-4,6-dichlorobenzofuraxan and 4,6-dinitro-5,7-dichlorobenzofuraxan according to claim 1, which have antibalantidia activity.

The claimed technical solution is illustrated in Fig. 1 - Fig. 2.

On FIG. 1 presents Table 1 containing the characteristics of the claimed compounds, obtained empirically.

On FIG. 2 presents Table 2, which shows the antibalantidia activity of the claimed compounds (1-7) of general formula I.

Further, the applicant provides a description of the claimed technical solution.

The claimed technical result is achieved by obtaining the claimed compounds 1 - 7 of general formula I , which are obtained by the reaction of the starting amines with 5,7-dichloro-4,6-dinitrobenzofuroxan and 4,6-dichloro-5-nitrobenzofuroxan:

The starting amines based on piperazine are commercial products:

1-benzhydrylpiperazin [https://ks20.ru/1-benzgidrilpiperazin-97-alfa-aesar-100-g?ysclid=l4sgvxx2km726630861],

1-(4-chlorophenyl)piperazine dihydrochloride

2-(piperazin-1-yl)pyrimidine (IUPAC name), also known as 2-(1-piperazinyl)pyrimidine: [https://rearus.ru/index.php?route=product/product&product_id=14062].

1-isopropylpiperazine : [https://rearus.ru/index.php?route=product/product&product_id=31316].

5,7-dichloro-4,6-dinitrobenzofuroxan (DNDHBF) is obtained according to a known method described, for example, in [Yusupova L.M., Spatlova L. / Optimization of the synthesis of 5,7-dichloro-4,6-dinitrobenzofuroxan // Bulletin of Kazan Technological University, 2011, p. 49-56].

5-Nitro-4,6-dichlorobenzofuroxan (NDCBF) is obtained by a known method described, for example, in [Mukhametsina A.M., Yusupova L.M., Khuziakhmetova A.N. / Optimization of the synthesis of 5-nitro-4,6-dichlorobenzofuroxan with quality control of feedstock, intermediate and final reaction products // Kazan National Research Technological University, June 11, 2016] [https://izron.ru/articles/problemy-meditsiny- v-sovremennykh-usloviyakh-sbornik-nauchnykh-trudov-po-itogam-mezhdunarodnoy-nauch/sektsiya-52-farmatsevticheskaya-khimiya-farmakognoziya-spetsialnost-14-04-02/optimizat-siya-sinteza-5-nitro-4- 6-dikhlorbenzofuroksana-s-kontrolem-kachestva-iskhodnogo-syrya-prome/].

The applicant further describes the preparation of compounds 1-7 generally.

To a solution of 4 mmol of 5,7-dichloro-4,6-dinitrobenzofuroxan or 4,6-dichloro-5-nitrobenzofuroxan in 50 ml of purified ethanol was added dropwise a solution of 16 mmol of the corresponding substituted piperazine or piperazine dihydrochloride derivative in 50 ml of purified ethanol.

The resulting solution is stirred at room temperature for 12 hours, then incubated for 24 hours. The resulting precipitate of the target product is filtered off, washed with ethyl alcohol and diethyl ether, dried in a vacuum.

The yield and characteristics of the synthesized compounds are shown in Table 1 in FIG. 1.

Further, the applicant provides examples of the implementation of the claimed technical solution.

Example 1 Preparation of 4,6-bis(4-benzhydrylpiperazin-1-yl)-5,7-dinitrobenzofuroxan ( 1 ) from 1-benzhydrylpiperazine and 5,7-dichloro-4,6-dinitrobenzofuroxan.

To a solution of 1.2 g (4 mmol) of 5,7-dichloro-4,6-dinitrobenzofuroxan in 50 ml of ethyl alcohol was added dropwise a solution of 4.04 g (16 mmol) of 1-benzhydrylpiperazine in 50 ml of ethyl alcohol.

The resulting solution is stirred at room temperature for 12 hours, then incubated for 24 hours. The resulting precipitate of the target product is filtered off, washed with ethyl alcohol and diethyl ether, dried in a vacuum.

The yield and characteristics of the resulting compound (1) are shown in Table 1 in FIG. 1.

Example 2 Preparation of 4-(4-benzhydrylpiperazin-1-yl)-6-chloro-5-nitrobenzofuroxan ( 2 ) from 1-benzhydrylpiperazine and 4,6-dichloro-5-nitrobenzofuroxan.

To a solution of 4,6-dichloro-5-nitrobenzofuroxan 1.0 g (4 mmol) in 50 ml of ethanol was added dropwise 4.04 g (16 mmol) of 1-benzhydrylpiperazine in 50 ml of ethyl alcohol.

The resulting solution is stirred at room temperature for 12 hours, then incubated for 24 hours. The resulting precipitate of the target product is filtered off, washed with ethyl alcohol and diethyl ether, dried in a vacuum.

The yield and characteristics of the resulting compound (2) are shown in Table 1 in FIG. 1.

Example 3 Preparation of 4,6-bis(4-(4-chlorophenyl)piperazin-1-yl)-5,7-dinitrobenzofuroxan ( 3 ) from 1-(4-chlorophenyl)piperazine dihydrochloride and 5,7-dichloro-4,6-dinitrobenzofuroxan.

To a solution of 1.2 g (4 mmol) of 5,7-dichloro-4,6-dinitrobenzofuroxan in 50 ml of ethanol is added dropwise a solution of 4.75 g (16 mmol) of 1-(4-chlorophenyl)piperazine dichloride in 50 ml of ethanol .

The resulting solution is stirred at room temperature for 12 hours, then incubated for 24 hours. The resulting precipitate of the target product is filtered off, washed with ethyl alcohol and diethyl ether, dried in a vacuum.

The yield and characteristics of the resulting compound (3) are shown in Table 1 in FIG. 1.

Example 4 Preparation of 6-chloro-4-(4-(4-chlorophenyl)piperazin-1-yl)-5-nitrobenzofuroxan ( 4 ) from 1-(4-chlorophenyl)piperazine dihydrochloride and 4,6-dichloro-5-nitrobenzofuroxan.

To a solution of 4,6-dichloro-5-nitrobenzofuroxan 1.0 g (4 mmol) in 50 ml of ethanol was added dropwise 4.75 g (16 mmol) of 1-(4-chlorophenyl)piperazine in 50 ml of ethyl alcohol.

The resulting solution is stirred at room temperature for 12 hours, then incubated for 24 hours. The resulting precipitate of the target product is filtered off, washed with ethyl alcohol and diethyl ether, dried in a vacuum.

The yield and characteristics of the resulting compound (2) are shown in Table 1 in FIG. 1.

Example 5 Preparation of 5,7-dinitro-4,6-bis(4-pyrimidin-2-yl)piperazin-1-yl)benzofuroxan (5) from 2-(piperazin-1-yl)pyrimidine and 5,7-dichloro-4 ,6-dinitrobenzofuroxan.

To a solution of 1.2 g (4 mmol) of 5,7-dichloro-4,6-dinitrobenzofuroxan in 50 ml of ethyl alcohol is added dropwise 2.63 g (16 mmol) of 2-(piperazin-1-yl)pyrimidine in 50 ml of ethyl alcohol .

The resulting solution is stirred at room temperature for 12 hours, then incubated for 24 hours. The resulting precipitate of the target product is filtered off, washed with ethyl alcohol and diethyl ether, dried in a vacuum.

The yield and characteristics of the resulting compound (5) are shown in Table 1 in FIG. 1.

Example 6 Preparation of 6-chloro-5-nitro-4-(4-pyrimidin-2-yl)piperazin-1-yl)benzofuroxan ( 6 ) from 2-(piperazin-1-yl)pyrimidine and 4,6-dichloro-5-nitrobenzofuroxan.

To a solution of 4,6-dichloro-5-nitrobenzofuroxan 1.0 g (4 mmol) in 50 ml of ethanol was added dropwise 2.63 g (16 mmol) of 2-(piperazin-1-yl)pyrimidine in 50 ml of ethyl alcohol.

The resulting solution is stirred at room temperature for 12 hours, then incubated for 24 hours. The resulting precipitate of the target product is filtered off, washed with ethyl alcohol and diethyl ether, dried in a vacuum.

The yield and characteristics of the resulting compound (6) are shown in Table 1 in FIG. 1.

Example 7 Preparation of 4,6-bis(4-isopropylpiperazin-1-yl)-5,7-dinitrobenzofuroxan ( 7 ) from 1-isopropylpiperazine and 5,7-dichloro-4,6-dinitrobenzofuroxan.

To a solution of 1.2 g (4 mmol) of 5,7-dichloro-4,6-dinitrobenzofuroxan in 50 ml of ethanol was added dropwise 2.05 g (16 mmol) of 1-isopropylpiperazine in 50 ml of ethyl alcohol.

The resulting solution is stirred at room temperature for 12 hours, then incubated for 24 hours. The resulting precipitate of the target product is filtered off, washed with ethyl alcohol and diethyl ether, dried in a vacuum.

The yield and characteristics of the resulting compound (7) are shown in Table 1 in FIG. 1.

Example 8 Investigation of the antibalantidiosis activity of the claimed compounds (1-7) general formula I .

The studies were carried out on pigs of various age groups spontaneously infected with balantidiasis.

As a control, an experiment was carried out without introducing the claimed compounds to the pigs. Before the start of the experiment, in order to identify balantidia in the body of pigs, they were coprologically examined under a microscope, for example, Biolam R-15 brand, using known methods: native smear method [https://dpo-ilm.ru/materials/76/158?ysclid=l55s94uz0192694919 ] and the Darling method [https://www.zoovet.ru/stati/slovar-veterinarnykh-terminov/metod_darlinga/?ysclid=l55s849pbh915661123].

At the same time, in order to better differentiate cysts and vegetative forms of balantidia (trophozoites), native smears were stained with Lugol's solution.

As a result of the study, balantadiosis was detected in all gilts, which is reflected in Table 2 in Fig. 2.

To conduct the study, vegetative forms of balantidia (trophozoites) were cultivated from the faeces of spontaneously infected pigs and the antibalantidia activity of the claimed compounds (1-7) of general formula I was studied on them and cysts.

For this purpose, vegetative forms of balantidia were grown in a sterile Erlenmeyr flask (1 g of faeces per 200 ml of tap water settled for 7 days) at a temperature of 23°C in the dark for 20 days. The resulting suspension with live balantidia and cysts was distributed with stirring in 9 ml in 22 sterilized tubes with lids and examined for the number of trophozoites and cysts in native smears under a microscope according to a well-known method [Pershin G.N. Methods of experimental chemotherapy. - M.: Medicine, 1971. - 245 p.].

The results are shown in Table 2 in FIG. 2, column "before the introduction of compound 1-7". At the same time, in each of the 22 experiments, 3 parallel measurements were carried out - the number of parasites in the field of view of the microscope was measured three times successively under a microscope: the minimum and maximum numbers are shown in Table 2 - the interval "from and to".

Then, to establish the antibalantidiosis activity of the claimed compounds, their solutions were prepared, with the initial 1% solutions being prepared first.

Then, into each tube (9 ml in each tube) with the initial number of trophozoites and cysts determined as described above , such a calculated amount of the prepared 1% solution of each test compound 1-7 was slowly added to ensure that accurate concentrations were created in each tube, and exactly:

to create a 0.1% concentration, 1 ml of a 1% solution was added dropwise,

to create a 0.01% concentration, 0.1 ml of a 1% solution was added dropwise,

to create a 0.001% concentration, 0.01 ml of a 1% solution was added dropwise.

Then, exactly 30 minutes later (using a stopwatch), the number of cysts and trophozoites of balantidia was measured in the field of view of the microscope in each test tube.

The results are shown in Table 2 in FIG. 2, column "after the introduction of compounds 1-7". At the same time, in each of the 22 experiments, 3 parallel measurements were also carried out.

From the results shown in Table 2, it can be seen that the claimed compounds ( 1-7 ) of general formula I showed high antibalantidia activity against the background of their 30-minute exposure to trophozoites and cysts at low concentrations - up to 0.001%.

In addition, the applicant measured the thermal stability of the claimed compounds (1-7) of the general formulaI, which amounted to 180-200°C according to the TG-DSC method, which indicates their high thermal stability.

Thus, from the foregoing, we can conclude that the applicant has achieved the claimed technical result, namely: expanded the arsenal of funds for this purpose by creating new generation compounds - piperazine-substituted derivatives of 5-nitro-4,6-dichlorobenzofuraxan and 4,6-dinitro-5 ,7-dichlorobenzofuraxan ( 1-7 ) of general formula I having antibalantidia activity at low concentrations (0.001%) and thermal stability up to 180-200°C according to the TG-DSC method.

Moreover, the claimed compounds have a low cost, since they are synthesized from inexpensive starting reagents by known standard methods.

Claims (3)

1. Piperazine-substituted derivatives of 5-nitro-4,6-dichlorobenzofuraxan and 4,6-dinitro-5,7-dichlorobenzofuraxan (1-7) of general formula I:

. 2. Piperazine-substituted derivatives of 5-nitro-4,6-dichlorobenzofuraxan and 4,6-dinitro-5,7-dichlorobenzofuraxan according to claim 1, having antibalantidia activity.

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