RU2700419C1 - 5-ethoxy-2-(ethylsulfanyl)-1h-benzimidazol-3-yum (2e)-3-carboxyprop-2-enoate, a method for production thereof and an actoprotector agent based thereon - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a novel compound – 5-ethoxy-2-(ethylsulfanyl)-1H-benzimidazol-3-yum(2E)-3-carboxyprop-2-enoate (C₁₁H₁₄N₂OS⋅C₄H₄O₄) of formula I. Invention also relates to a method of producing compound of formula I

.

Method involves mixing mixture of 5-ethoxy-1H-benzimidazole-2-thiol, diethyl sulphate and a base in molar ratio of 1:1.1:1.1 in an aqueous medium at room temperature. Formed alkylation product – 5-ethoxy-2-(ethylsulfanyl)-1H-benzimidazole – in the form of a precipitate is separated and treated with fumaric acid in molar ratio of 1:1 in acetone medium at 50 °C with further extraction of end product. Base is usually NaOH. Acetone is distilled to extract the target product.

EFFECT: compound has antihypoxic and stress protective action and can be used as an active ingredient for the actoprotector agent.

5 cl, 3 ex

Description

The group of inventions relates to medicine and pharmacy and relates to a new derivative of 5-ethoxy-2-ethylthiobenzimidazole, namely: 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazole-3-ium (2E) -3-carboxyprop-2-enoate (C ₁₁ H ₁₄ N ₂ OS⋅C ₄ H ₄ O ₄ ) of formula I, a process for its preparation and an actoprotective agent containing it.

The closest in structure and pharmacological properties to the claimed agent is 5-ethoxy-2-ethylthiobenzimidazole hydrochloride of the formula II (prototype):

Antihypoxic, stress-protective [Lozinsky M.О., Bobkov Yu.G., Kurochkin I.G., Losev A.S., Zaranovskaya E.V., Dmitruha V.S., Zavatsky V.N., Ivanova I.A., Savelyev V .L, Seredenin S.B., Zurdinov A.Z., Leshchinyuk I.I., Vinogradov V.M., Katkov V.F., Dyumaev K.M. Hydrochloride of 5-ethoxy-2-ethylthiobenzimidazole with antihypoxic and stress-protective activity / Application 3641355/04 from 07/13/1983. Patent No. 1259652. Publ. 11/10/1996], as well as anti-asthenic [Shabanov P.D. Clinical pharmacology of metaprot, a new anti-asthenic drug with psychoactive properties // Clinical Pharmacology and Drug Therapy Reviews - vol. 7, vol. 3, pp. 48-81] the activity of such compounds related to 2-mercaptbenzimidazole derivatives.

The disadvantages of 5-ethoxy-2-ethylthiobenzimidazole hydrochloride include insufficient actoprotective activity.

A known method of producing 5-ethoxy-2-ethylthiobenzimidazole hydrochloride by condensation of 4-ethoxy-1,2-phenylenediamine with potassium ethyl xanthate, followed by alkylation of the resulting compound with ethyl bromide and crystallization from hydrochloric acid [Lozinsky M.O., Bobkov Yu.G., Kurochkin I. G, Losev A.S., Zaranovskaya E.V., Dmitruha V.S., Zavatsky V.N., Ivanova I.A., Savelyev V.L., Seredenin S.B., Zurdinov A.Z., Leshchinyuk I.I., Vinogradov V. M, Katkov V.F., Dumayev K.M. Hydrochloride of 5-ethoxy-2-ethylthiobenzimidazole with antihypoxic and stress-protective activity / Application 3641355/04 from 07/13/1983. Patent No. 1259652. Publ. 11/10/1996].

The objective of the group of inventions is to expand the arsenal of actoprotective agents, the creation of a new derivative of 5-ethoxy-2-ethylthiobenzimidazole, which is not described in the literature, which has low toxicity and has actoprotective activity that exceeds the indicated activity of drugs used in medical practice.

The technical results to which the invention is aimed is to obtain a new compound of formula I, which can potentially act as an actoprotective agent, and to develop a method for its synthesis with a high yield of the reaction product.

The task is carried out by obtaining a new substance 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) 3-carboxyprop-2-enoate of formula I by reacting 5-ethoxy-1H-benzimidazole-2-thiol with diethyl sulfate in the presence of a base in an aqueous medium at a molar ratio of 1: 1: 1 and further processing of the obtained 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazole with fumaric acid in acetone at 50 ° C with the further isolation of the target product.

The task is also achieved by the fact that the target product is isolated by distillation of acetone.

The task is also carried out by proving the low toxicity of 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) 3-carboxyprop-2-enoate and the study of its actoprotective activity. The results of these tests allow us to offer the claimed compound as a potential actoprotective agent.

The invention is illustrated by examples of synthesis and study of pharmacological properties.

Example 1

Synthesis procedure for 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) 3-carboxyprop-2-enoate.

A method of obtaining 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) 3-carboxyprop-2-enoate was carried out and studied on standard commercial raw materials.

When 5-ethoxy-1H-benzimidazole-2-thiol was reacted with diethyl sulfate in the presence of a base, 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazole was synthesized in an aqueous medium.

To 19.4 g (0.1 mol) of 5-ethoxy-1H-benzimidazole-2-thiol in 100 ml of water, 4.4 g (0.11 mol) of sodium hydroxide and 17.0 g (0.11 mol) of diethyl sulfate were added. The mixture was stirred for 24 hours at room temperature. The product was filtered off, washed with water, dried in air and recrystallized from aqueous ethanol. Yield 20 g (90%). T. pl. 117-118 ° C.

1 H NMR (500 MHz, DMSO-d ₆ ): 1.28-1.38 (m, 6H, CH ₃ ), 3.23 (q, j = 5.7 Hz, 2H, SCH ₂ ), 3.99 (q, j = 5.7 Hz, 2H, OCH ₂ ), 6.73 (dd, j = 8.0, 2.0 Hz, 1H), 6.97 (s, 1H), 7.33 (d, j = 8.0 Hz, 1H), 12.5 (br, 1H, NH). 13C NMR (125 MHz, DMSO-d ₆ ): 15.2, 15.7, 26.2, 63.8, 94.6, 111.1, 111.3, 118.4, 130.5, 149.4, 154.8.

The 1H NMR spectrum of 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazole in DMSO-d ₆ contains characteristic proton signals of ethyl groups 1.28-1.38 (m, 6H, CH ₃ ), 3.23 (q, j = 5.7 Hz, 2H , SCH ₂ ), 3.99 (q, j = 5.7 Hz, 2H, OCH ₂ ) and multiples of aromatic protons 6.73 (dd, j = 8.0, 2.0 Hz, 1H), 6.97 (s, 1H), 7.33 (d, j = 8.0 Hz, 1H). In addition, a broadened singlet of the proton NH 12.5 (br, 1H, NH) is observed. The 13C NMR spectrum of 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazole in DMSO-d ₆ contains carbon atom signals from ethyl groups (15.2, 15.7, 26.2 (SCH ₂ ), 63.8 (OCH ₂ ) ppm) and seven signals of the carbon atoms of benzimidazole (94.6, 111.1, 111.3, 118.4, 130.5, 149.4 and 154.8 ppm).

5-Ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) 3-carboxyprop-2-enoate was synthesized by the reaction of 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazole with fumaric acid.

To 22.2 g (0.1 mol) of 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazole in 100 ml of acetone was added 11.6 g (0.1 mol) of fumaric acid. The mixture was stirred for 1 hour at 50 ° C. Acetone was distilled off on a rotary evaporator, the crystals were washed with ether and dried in air. Yield 31.1 g (92%).

The structure of the synthesized substance was proved by 1H and 13C-NMR spectroscopy. 1 H NMR (500 MHz, DMSO-d ₆ ): 1.31-1.41 (m, 6H, CH ₃ ), 3.27 (q, j = 5.7 Hz, 2H, SCH ₂ ), 3.96 (q, j = 5.7 Hz, 2H, OCH ₂ ), 6.51 (s, 2H, CH = CH), 6.77 (dd, j = 8.0, 2.0 Hz, 1H), 6.94 (s, 1H), 7.37 (d, j = 8.0 Hz, 1H), 12.1 ( bc, 2H, NH). ¹³ C NMR (125 MHz, DMSO-d ₆ ): 15.7, 16.2, 27.2, 64.7, 95.6, 113.3, 112.5, 118.7, 131.4, 134.1, 151.4, 156.3, 171.2.

The 1H 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) 3-carboxyprop-2-enoate NMR spectrum in DMSO-d ₆ contains characteristic proton signals of ethyl groups 1.31-1.41 (m, 6H, CH ₃ ), 3.27 (q, j = 5.7 Hz, 2H, SCH ₂ ), 3.96 (k, j = 5.7 Hz, 2H, OCH ₂ ), a singlet of ethylene protons of fumaric acid 6.51 (s, 2H, CH = CH) and multiples of aromatic protons 6.77 (dd, j = 8.0, 2.0 Hz, 1H), 6.94 (s, 1H), 7.37 (d, j = 8.0 Hz, 1H). In addition, a strongly broadened proton signal of NH 12.1 (br, 2H, NH) is observed. The 13C NMR spectrum of 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) 3-carboxyprop-2-enoate in DMSO-d ₆ contains signals of carbon atoms of ethyl groups (15.7, 16.2, 27.2 (SCH ₂ ), 64.7 (OCH ₂ ) ppm), typical signals of carbon atoms of protonated benzimidazole (95.6, 113.3, 112.5, 118.7, 131.4, 151.4, 156.3 ppm) and fumaric acid (134.1, 171.2 ppm) )

Example 2. Determination of acute toxicity.

The acute toxicity of 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) 3-carboxyprop-p-2-enoate was determined on outbred white male mice weighing 24 ± 2 g. Before the test, the animals were separated into 2 groups of 5 mice each. All 2 groups received the test substance - 5-ethoxy-2- (ethylsulfanyl) - 1H-benzimidazol-3-ium (2E) -3-carboxyprop-2-enoate. 3-4 hours before the introduction of the animals were restricted in food, but watered. After the fasting period, the animals were weighed and the dose was calculated based on body weight data, then the test drug was administered to them.

The 1st and 2nd groups received the test compound by intragastric administration of the solution using a probe at a dose of 2 g / kg and 1.5 g / kg, respectively. After the administration of the drug, animals were constantly monitored, recording the time of onset of the first clinical signs of intoxication. Assessment of animal survival was carried out individually after administration of the dose at least once in the first 30 minutes, regularly during the first 24 hours (especially the first four hours), and then daily for 14 days. Observations, including separate reports for each animal, were systematically observed. The development of the main symptoms and the time of death of the animals were recorded.

As a result, in the 1st and 2nd groups, the survival rate was 100%.

Based on GOST No. 32296-2013 “Test methods for the effects of chemical products on the human body. The main requirements for conducting tests to assess acute toxicity in case of intragastric administration by the fixed-dose method ”the studied drug is assigned to the 5th class of acute toxic hazard according to the GHS classification and is low toxic.

The acute toxicity of the claimed compound is comparable with the acute toxicity of 5-ethoxy-2-ethylthiobenzimidazole hydrochloride.

Example 3. Determination of actoprotective activity.

To assess the physical performance of 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazole-3-ium (2E) 3-carboxyprop-p-2-enoate, we used the standard method for pharmacological studies of animals with maximum loading and load method . To carry out the limit swimming test for laboratory animals in the intercostal space using special one-time fasteners, a load of 7.5% of the animal’s body weight and corresponding to the average level of aerobic-anaerobic load intensity was recorded. Studies were performed on 40 white outbred mice males weighing 22-25 g. Animals were divided into 4 groups, 10 mice each.

The test animals were weighed intragastrically with a probe once administered the test compound 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) -3-carboxyprop-2-enoate at a dosage of 25 mg / kg and 12.5 mg / kg and the reference preparation is 5-ethoxy-2-ethylthiobenzimidazole hydrochloride at a dosage of 25 mg / kg. Animals of the control group received 0.9% NaCl in equivalent volumes.

The studies were carried out in a swimming installation, which is a 200-liter pool (height 40 cm, width 35 cm and length 80 cm), filled with water to half. Inside it was a Plexiglas contour (height 30 cm, width 30 cm and length 75 cm), divided into 10 compartments (15 × 15 cm each). The installation was filled to half with desaturated water at a temperature of 22-24 ° C. Water desaturation was carried out by preliminary sedimentation during the day. During the test, the animals were placed in the appropriate compartment of the pool and immediately turned on the stopwatch. The criterion for the end of the test was the immersion of the animal at the bottom of the pool without swimming movements or an unsuccessful attempt to surface for more than three seconds, after which the animal was removed from the pool, dried with a soft cloth and placed in a standard cage.

It was found that the claimed drug in a dosage of 25 mg / kg with a single injection significantly (p <0.05) increased the physical performance of mice by 1.19 times compared with animals in the control group and exceeded the effect of 5-ethoxy-2-ethylthiobenzimidazole hydrochloride (dose 25 mg / kg) 1.06 times.

To assess the strength characteristics of animals, a paw grip strength test was used. A dynamometer (Grip Strength Meter, TSE Systems, Germany) was used for its conduct. Before the test, the animals were divided into 3 groups, 8 mice each: the 1st — control group, intragastrically using a probe received 0.9% NaCl in a volume of 10 ml / kg, the 2nd group received a reference preparation of 5-ethoxy- 2-ethylthiobenzimidazole hydrochloride at a dose of 25 mg / kg, the 3rd group received the test compound 5-ethoxy-2- (ethylsulfanyl) - 1H-benzimidazole-3-ium (2E) 3-carboxyprop-p-2-enoate at a dose of 25 mg / kg All drugs were administered intragastrically using a probe 30 minutes before training 3 times a week for 1 month.

The training was carried out in 3 sets with a break of 1 minute by means of "negative repetitions" for the front paws using a dynamometer wire. The animal was allowed to grab the wire with its paws with the ability to pull itself towards it by inertia, after which it was gently pulled back until the legs were fully extended. The approach was carried out until the experimenter felt the lack of strength in the animal to pull itself to the wire.

As a result, after 4 weeks of training, the grip strength of animals that were injected with the test compound 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) 3-carboxyprop-p-2-enoate (dose 25 mg / kg) significantly (p <0.05) increased 1.86 times relative to the initial values, 1.11 times relative to the control group and 1.33 times (p <0.005) relative to the comparison drug 5-ethoxy-2-ethylthiobenzimidazole hydrochloride ( dose of 25 mg / kg).

Thus, the claimed tool is low toxic and exhibits the highest act protective activity relative to the comparison drug and the control group and can be recommended as a potential act protective agent for use in medical practice.

Claims (6)

1. 5-Ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) -3-carboxyprop-2-enoate of the formula I.

2. A method for producing 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) -3-carboxyprop-2-enoate of formula I, characterized in that the mixture is 5-ethoxy-1H-benzimidazole-2- thiol, diethyl sulfate and base in a molar ratio of 1: 1.1: 1.1 in an aqueous medium is stirred at room temperature, the resulting alkylation product - 5-ethoxy-2- (ethylsulfanyl) -1H-benzimidazole - is separated off and treated in the form of a precipitate fumaric acid in a molar ratio of 1: 1 in acetone at 50 ° C with further isolation of the target product. 3. The method according to p. 2, characterized in that NaOH is used as the base. 4. The method according to p. 2, characterized in that in order to isolate the target product, acetone is distilled off. 5. 5-Ethoxy-2- (ethylsulfanyl) -1H-benzimidazol-3-ium (2E) -3-carboxyprop-2-enoate of formula I as an active ingredient for an actoprotective agent.