PL236592B1 - New derivative of N-dimethylisopropylpropane - Google Patents

Abstract

The subject of the application is the compound N-[1-(8-isopropyl-8-azabicyclo[3.2.1]oct-3α1yl)]-ethane-1,2-diamine of formula 1, and its pharmaceutically acceptable salts, as well as its use as hypotensive, analgesic and anti-inflammatory agent.

Description

Description of the invention

The subject of the invention is a tropane derivative, more particularly nortropane.

Tropan does not occur in nature, but is a key element of the tropane alkaloids, which are secondary metabolites of plants, mainly from the Solanaceae, Erythroxylaceae, Convolvulaceae and Euphorbiaceae families. Among the tropane alkaloids with known pharmacological activity, atropine, cocaine, scopolamine, hyoscyamine, homatropine and their derivatives should be mentioned.

New atropine derivatives used in therapy include Ipratropium and Tiotropium, which in the form of quaternary ammonium salts are used in respiratory diseases, showing lower side effects than other drugs with the above-mentioned pharmacological activity, which is their serious advantage.

It should be noted that there are still new trends in the search for tropane derivatives with more favorable and new properties, other than the compounds used so far, as well as in the study of the mechanism of their pharmacological action. There are more and more reports that tropane derivatives may act not only on the receptors of the parasympathetic system. For example, Tropisetron, a selective 5HT3 serotonergic receptor antagonist, has been used as an agent to suppress postoperative or chemotherapy-induced emesis, and has also shown anti-inflammatory effects. Likewise, Maraviroc, by not acting in the parasympathetic system, antagonizes the CCR5 receptor and may improve the lives of HIV patients. In turn, Pervilens, alkaloids isolated from Erythroxylum pervillei, show activity as calcium channel blockers comparable to verapamil, showing no effect on the autonomic nervous system. Buscopan (Hyoscini butylbromidum), Scopolan Compositum or Bellergot are drugs with an analgesic effect by relaxing within the digestive tract. Tropane derivatives with antipsychotic and antihypertensive activity (e.g. vasopressin receptor blockers) are also known.

The review of tropane-derived drugs shows that they have a wide variety of applications in medicine due to different mechanisms of interaction and different binding to many receptors. The authors of the present invention have found that the new tropane derivatives containing in their structure the ethane-1,2-diamine system exhibit favorable pharmacological properties, namely lowering blood pressure with relatively low toxicity, as well as analgesic and anti-inflammatory properties.

The invention is based on N- [1- (8-isopropyl-8-azabicyclo [3.2.1] oct-3a-yl)] ethane-1,2-diamine of formula 1, and pharmaceutically acceptable salts thereof.

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Formula 1

Preferably the compound of the present invention is in the form of a base or trihydrochloride.

The tropane derivative of the invention exhibits hypotensive, analgesic and anti-inflammatory properties when administered intravenously and intragastrically.

It was found that the compound is relatively non-toxic after intragastric administration - the indicative acute toxicity is above 3 g / kg, while the effects in the behavior of the animals tested were already obtained at a dose of 30 mg / kg, i.e. at a dose approximately 100 times lower than the acute toxicity dose.

The compound according to the invention has a pronounced antihypertensive effect, both after intravenous and intragastric administration, and the effect is proportional to the dose administered. The dynamics of action after intravenous administration is characterized by a rather sharp decrease in blood pressure, after which the pressure gradually increases. After 120 minutes after administration, the pressure has not returned to the baseline value. The antihypertensive effect was much more pronounced in animals with genetically determined hypertension (SHR) and persisted even 24 hours after the administration of the preparation.

PL 236 592 B1

The conducted pharmacological analysis showed that the first phase of the hypotensive effect is caused by the blockage of the ganglia of the vegetative system. The remaining component in the mechanism of the hypotensive action may be related either to the adrenergic system or to a direct effect on the smooth muscles of blood vessels.

The compound of the invention has an anti-edema activity equal to that of the acetylsalicylic acid used as the standard preparation.

The synthesis of the compound of the invention was carried out according to the method shown in the scheme. Necessary for the synthesis of 8-isopropyl-8-azabicyclo [3.2.1] -3-one was obtained by the Robinson method in the reaction of succinic aldehyde, acetone dicarboxylic acid and isopropylamine, maintaining the appropriate pH of the reaction mixture (pH 4-5) with 30% NaOH solution and concentrated HCl. Maintaining the appropriate pH had an effect on the yield of the reaction.

The subject of the invention is presented in the examples.

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N- [1- (8-isopropyl-8-azabicyclo [3.2.1] oct-3a-yl)] ethane-1,2-diamine trihydrochloride

An ampoule with 10.0 g of 8-isopropyl-8-azabicyclo [3.2.1] octane-3-one (1a), 7.2 g of N- (2-aminoethyl) -acetamide and 0.1 g of N- (2-aminoethyl) -acetamide was placed in the apparatus for high pressure hydrogenation. g PtO2 in 45 ml methanol. The whole was hydrogenated at 65 atm for 4 hours, at 50 ° C. The catalyst was then filtered off, the filtrate was concentrated and the obtained oil was distilled under reduced pressure, collecting the fraction boiling at 145 ° C / 0.022 Torr. The thus obtained N- [2- (isopropyl-8-azabicyclo [3.2.1] oct-3a-ylamino) ethyl] -acetamide was dissolved in 100 ml of dilute hydrochloric acid (concentrated hydrochloric acid: water 1: 1) and heated boiling for 3 hours. The reaction mixture was then concentrated. The brown residue was dissolved in 100 ml of methanol and refluxed with 1 g of active charcoal for 10 minutes. After filtering off the carbon and cooling the filtrate, a white precipitate of N- [1- (8-isopropyl-8-azabicyclo [3.2.1] oct-3a-yl)] ethane-1,2-diamine trihydrochloride crystallized, which was recrystallized from methanol . 10.7 g (53%) of the product with m.p. 262-266 ° C.

Elemental analysis for the formula C12H25N3 x 3HCl x H2O m.w. 338.75

Cal: C% = 42.6, H% = 8.9, N% = 12.4

Aper .: C% = 42.5, H% = 8.9, N% = 12.5

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N- [1- (8-isopropyl-8-azabicyclo [3.2.1] oct-3a-yl)] ethane-1,2-diamine

1.0 g of N- [1- (8-isopropyl-8-azabicyclo [3.2.1] oct-3a-yl) trihydrochloride was suspended in an ethanolic solution of sodium ethoxide formed by the reaction of 0.2 g of metallic sodium with 20 ml of absolute ethanol. ] -ethane-1,2-diamine (3a) and stirred with a magnetic stirrer for 10 minutes. The resulting suspension was filtered to separate the separated sodium chloride. The filtrate was concentrated on an evaporator until constant weight was obtained. 0.59 g (95.2%) of N- [1- (8-isopropyl-8-azabicyclo [3.2.1] oct-3a-yl)] ethane-1,2-diamine was obtained.

HRMS: C12H25NsNa Cald. 234.1949 Std. 234.1946 (ppm 1.0).

1H-NMR (ppm / TMS): 3.40; C1, C5 2H, 2.87 C3H t, ³ J1 = 6.5, J2 = 0.0, 2.78 C9H2 t ³ J = 6.0, 2 , 68 C11H sp ³ J = 6.0, 2.62 C10H2 t, ³ J = 6.0, 2.05 C6H (E), C7H (E) m, 1.97 C2H (E), C4H (E) pk, 1.87 C6H (A), C7H (A) m, 1.52 NH, NH2 bs, 1.41; C2H (A), C4H (A) pd, 1.08 C12H3, C13H3d ³ J = 6.0 ¹³ C-NMR: 54.43 C1, C4, 50.97 C9, 50.02 C11.45.77 C3, 42.22 C10, 33.22 C2, C4, 27.32 C6, C7, 21.57 C12.C13

The N- [1- (8-isopropyl-8-azabicyclo [3.2.1] oct-3a-yl)] ethane-1,2-diamine trihydrochloride obtained in the above synthesis, containing a water molecule of formula C12H23N3 x 3HCl x H2O, with a molecular weight of 338.75, was subjected to pharmacological tests.

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a. Study of the effects on blood pressure and heart rate in drugged normotensive rats.

Measurements were carried out on rats, female, strain Ipf; RIZ, weighing about 300 g, anesthetized with ethyl urethane at a dose of 1.2 g / kg ip. The animals were fasted for 24 hours. before the experience. Arterial blood pressure was measured using the carotid blood method using the EMT-31 electromanometer and the EMT-35 pressure transducer. The electrocardiogram was recorded from limb leads with needle electrodes. Simultaneous recording of pressure and ECG was carried out continuously on the Mingograph 61.

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The test preparation was administered intravenously (femoral vein) in the volume of 1 ml / kg at the following doses: 3.9, 1.3 and 0.43 mg / kg, which were 1/10, 1/30 and 1/90 part of the established ID50, respectively. for mice with the same route of administration.

At the three doses used, the preparation produced a dose-proportional reduction in blood pressure. The pressure drops were most pronounced 15 minutes after administration of the preparation (about 50%). A systematic increase in pressure was observed over a period of 15 minutes to 1.5 hours, but until the end of the observation (3 hours) it was approximately 25% below the baseline value (Table 1).

b. Study of the effects on blood pressure and heart function in non-drugized normotensive (NR) and genetically hypertensive (SHR) rats.

Measurements were carried out on female rats with a body weight of 220-250 g. The animals were fasted for 24 hours. before the experience. The preparation was applied intragastrically, in 0.5% gum arabic gruel, in a dose of 200 mg / kg in a volume of 2 ml / kg. Systolic blood pressure was measured on a rat tail bloodless method with a photoelectric transducer. The rats were placed in a thermostatic cage to keep the internal body temperature stable. A cuff about 2 cm wide was placed on the tail closer to the root, and a photoelectric transducer was placed below. The measurement principle is based on the simultaneous registration of pressure changes in the clamping cuff and the pulse wave curve received from the caudal arteries below the pressure point. Pressure changes in the clamping cuff were measured and recorded using an EMT-34 pressure transducer and an EMT-35 electrometer. The course of the pulse wave line was recorded with the use of a proprietary photoelectric converter connected to the universal EMT-12 amplifier. The measured values of pressure in the clamping cuff and the course of the pulse wave, from which the frequency of heart contractions was additionally read, were recorded on a Hingograf 81 physiopoligraphy.

The preparation in the dose of 2200 mg / kg significantly decreased blood pressure, both in normotensive rats and in genetically determined hypertension. The antihypertensive effect was more pronounced in SHR rats and persisted even after 24 hours (approximately -25%) from the administration of the preparation. At the same time, normotension rats showed a return to baseline values (Table 2).

The decrease in blood pressure in normotensive rats in the first two hours of observation was accompanied by tachycardia, and then the heart rate remained close to the baseline level. In SHR rats, heart rate decreased throughout the observation period (Table 2).

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Study of anti-inflammatory properties.

The anti-inflammatory properties were assessed in a biological model of acute inflammation in the carrageenan test.

The carrageenan test was performed on fasted rats of both sexes of the herds of the strain Ipf; RIZ, weighing from 100 to 150 g. The groups of animals were 10 each. Acute inflammation was induced by injecting 0.1 ml of 1% carrageenan solution according to the method of Winter and Lance into the hind paw of rats. 1 hour before injection, carrageenan was administered intragastrically to rats in the form of a suspension in 5% gum arabic containing the test compound at a dose of 50 mg / kg body weight. (1/10 LD50). All preparations were administered in a volume of 1 ml / 100 g c.c. rat. The control group received a 5% gum arabic solution in the volume of 1 ml / 100 g c.c. 1 hour before the injection of carrageenan by gavage. As a standard drug, acetylsalicylic acid at a dose of 37.5 mg / kg body weight was used. (1/10 LD50). Acetylsalicylic acid was administered orally as a suspension in 5% gum arabic in the volume of 1 ml / 100 g c.c. The volume of rats' paws was measured three times: before and 2 and 4 hours after the injection of carrageenan. The degree of edema inhibition was expressed as a percentage. The results are shown in Table 3.

The tested compound showed an anti-inflammatory effect as it inhibited the swelling of the rat's paw by 31.60% after 2 hours and by 29.43% after 4 hours. The differences between the amount of paw volume gain in rats treated with the compound of the invention and the size of the foot volume gain in control rats were statistically significant at 2 and 4 hours.

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Study of analgesic properties.

Analgesic activity in the "drag" test in mice.

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The test compound administered intragastrically at doses of 15, 30, 45, and 60 mg / kg reduced the number of stalls in response to a chemical irritant stimulus. Number of animals in group 6-8.

The compound showed the strongest analgesic effect in this test at a dose of 60 mg / kg, reducing statistically significantly the number of stretches in response to a chemical irritant stimulus by 92.4%. When administered at a dose of 45 mg / kg, it statistically significantly reduced the number of stays by 74.3% and at a dose of 30 mg / kg by 54.5%. At the lowest dose of 15 mg / kg, the weakest, statistically insignificant analgesic effect was observed. (The ED 50 value is 27.7 mg / kg and the teragent index is 108.3)

Analgesic activity in the "hot" plaque test.

The test compound administered intragastrically in doses of 30.45 and 60 mg / kg did not change the reaction time to the thermal stimulus.

Analgesic activity in the writhing test according to Witkin.

The test compound and Ansolysen were intragastrically administered to mice at doses of 60 mg / kg and 15 mg / kg. After 30 min, 0.2 ml / mouse was injected intraperitoneally with 0.5% acetic acid. Immediately after injection, the number of body turns of the animals over 20 minutes was counted. The results were related to the control group. Both compounds exerted a similar analgesic effect, but the tested compound was stronger.

Claims (3)

Patent claims 1. N- [1- (8-isopropyl-8-azabicyclo [3.2.1] oct-3a-yl)] ethane-1,2-diamine of formula 1, and pharmaceutically acceptable salts thereof. H0 Μ \ Formula 1 2. A compound according to claim 1 in base or trihydrochloride form. 3. N- [1- (8-isopropyl-8-azabicyclo [3.2.1] oct-3a-yl)] ethane-1,2-diamine for use as an antihypertensive, analgesic and anti-inflammatory agent.