HU206213B - Process for producing 2,3,3a,4,5,6-hexahydro-8-cyclohexyl-1h-pyrazino-(3,2,1-j,k)carbazole hydrogen chloride - Google Patents

Abstract

2,3,3a,4,5,6- hexahydro-8-cyclohexyl- 1H-pyrazino(3,2,1,1-j,k) carbazole hydrochloride of formula (I) is new. (I) is obtd. by alkylation of 6-cyclohexyl-3,4-dihydrocarbazol-1 (2H)-one with beta-(N,N-dibenzylamino)ethyl chloride hydrochloride in a two-phase system comprising an aromatic hydrocarbon and a 30-40% aq. soln. of alkali in the presence of an interphase transfer catalyst at 85-100 deg.C, followed by hydrogenation of the resulting 6-cyclohexyl-9-beta- (N,N-dibenzylamino) ethyl-3,4-dihydrocarbazol -1(2H)-one over a Pd catalyst on a carrier in a higher aliphatic alcohol at 50-70 deg.C and 1-30 atmos. The obtd. 2,3,3a,4,5,6 -hexahydro-8- cyclohexyl-1H-pyrazino(3,2,1-j,k) carbazole is then converted to the hydrochloride. The interphase transfer catalyst is selected from tetra-alkyl-or trialkyl benzyl-, or trialkyl(alkylbenzyl)ammonium halide, or polyethylene glycol, or a mixt. of benzyl chloride and triethylamine or dimethyl formamide. The Pd catalyst comprises Pd bisacetyl acetonate or Pd hydroxide, and the catalyst carrier in C or asbestos. When Pd bisacetyl acetonate is used as catalyst on a carbon carrier the hydrogenation stage is pref. carried out at 50-60 de.gC and at 10-20 atmos.

Description

The present invention relates to the field of organic chemistry, more particularly to the preparation of a new compound, 2,3,3a, 4,5,6-hexahydro-8-cyclohexyl-1H-pyrazino [3,2,1-j, k] carbazole hydrochloride. The compound has the formula (I). Based on its anti-depressant activity, the compound is useful as an active ingredient in anti-depression pharmaceutical compositions.

It is known to prepare 2,3,3a, 4,5,6-hexahydro-8-methyl-1H-pyrazino [3,2, 1j, k] carbazole hydrochloride, the active ingredient of the drug Pyrazidol (Pirlindolum, Perlindole) (1370528 British Patent Nos. 1340529 and 1340529).

The compound is prepared by reacting 1-oxo-1,2,3,4-tetrahydro-6-methylcarbazole with a base, and the resulting product is alkylated with chloroacetonitrile in an organic solvent to give 1-oxo-1,2,3 4-Tetrahydro-6-methyl-9-cyanomethylcarbazole is subjected to a reduction ring in an organic solvent in the presence of a hydrogenation catalyst with hydrogen gas at 30-60 ° C and a pressure of 30-70 atoms, and the product is reacted with hydrochloric acid and the hydrochloride is isolated.

The process requires complex, high amounts of solvent and especially high pressure.

Pyrazidol, a drug containing this active ingredient, reduces immobilization time, reduces the depressant effect of reserpine, and enhances the effects on d, l-amphetamine, 1-dofa and 5-hydroxytryptophan and the central nervous system in tests of behavioral stress. Pyrazidol is a reversible, selective inhibitor of monoamine oxidase type A, which also inhibits (rat) resorption of noradrenaline and serotonin through cerebral synapses.

Pyrazidol has no cholinolytic effect; its various etologies are effective in depression with psychomotor inhibition. The lack of a cholinolytic effect allows the use of the drug in cases where the use of Imipramine and other products in this class is contraindicated. In some cases, such as hypersensitivity, taking Pyrazidol may cause dry mouth, tachycardia and dizziness. The therapeutic effect of the drug occurs between days 5 and 12.

The compound of the present invention is novel and has not yet been described in the literature.

SUMMARY OF THE INVENTION The object of the present invention is to provide a process for the preparation of new compounds which has a high antidepressant effect, a high therapeutic efficacy, a low toxicity and a good physiological tolerance, and its action is rapid.

The above problem was solved by the preparation of 2,3,3a, 4,5,6-hexahydro-8-cyclohexyl-1H-pyrazino [3,2,1-j, k] carbazole hydrochloride of formula (I). According to the invention, the compound of formula (I) is prepared by reacting 6-cyclohexyl-3,4-dihydrocarbazol-1- (2H) -one with P- (N, N-dibenzylamino) ethyl chloride from an aromatic hydrocarbon and 36-401 In a two-phase system consisting of a% aqueous alkali metal hydroxide solution, the phase transfer catalyst is tetraalkyl or trialkylbenzyl or trialkyl (alkylbenzyl) ammonium halide, or a mixture of benzyl chloride and triethylamine or dimethylformamide on C the resulting 6-cyclohexyl-9- [p- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbazol-1- (2H) -one in the presence of a lower aliphatic alcohol supported by palladium catalyst at 50-70 ° C. After hydrogenation at 30 t, the resulting 2,3,3a, 4,5,6-hexahydro-8-cyclohexyl-1H-pyrazino [3,2,1j, k] carbazole is hydrochloride formed and the salt isolated.

The palladium catalyst is preferably palladium bis (acetylacetonate) or palladium hydroxide on activated carbon or asbestos. The most preferred catalyst is palladium bis (acetylacetonate) on carbon. The hydrogenation temperature is preferably 5060 ° C and the pressure is preferably 10-20 at.

The compound of formula (I) has a potent antidepressant effect and a number of properties which are characteristic of an antidepressant (reducing the depressant effect of reserpine, enhancing the stimulating effect of d, 1-amphetamine, 1-dopa, 5-hydroxytryptophan and other pharmacological effects). According to a number of pharmacological indicators, the effect of the compound of the invention is 2 to 10 times greater than that of the Pyrazidol pharmaceutical formulation.

Like Pyrazidol, the compound of formula (I) has an inhibitory effect on the activity of the monoamine oxidase enzyme, i.e., the compound of formula (I) is reversible. selective monoamine oxidase type A inhibitor.

Pharmacokinetic studies have shown that the compound of formula (I) is rapidly absorbed through the gastrointestinal tract and rapidly distributed to the bloodstream and to individual organs. Compound (I) penetrates well into brain tissue and remains there for 3 to 6 hours, in contrast to Pyrazidol, which remains for up to 1.5 hours. The therapeutic effect is 2-5 after the start of treatment. day.

The compound is slightly toxic. White mice were dosed with LD _{50 of} 1.3 g / kg and 2.5 g / kg in rats.

The drug of the present invention does not adversely affect the parenchyma organs; no cardiotoxic effect; carcinogenic, mutagenic, non-allergenic; does not affect the body's immune system; has no cholinolytic effect. The active ingredient is well tolerated by patients.

The compound of formula (I) of the present invention forms a white, pale yellow powder; a greenish shade is allowed. The compound is slightly soluble in 95% alcohol, chloroform, practically insoluble in water and ether, m.p. 249-252 ° C (with decomposition from aqueous methanol).

The structure of the compound is confirmed by elemental analysis, UV and NMR spectra, and mass spectral data.

The antidepressant effect of the compound of formula (I) was tested.

The effect of the compound on immobilization time in the Porsolt behavioral float test (Porsolt et al., 1977) was tested in male and female white mice weighing 16-18 g. Compounds were dosed at doses of 1.0, 2.5 and 5.0 mg / kg, respectively, with Pyrazidol and Imipramine at 10 and 2.5 mg / kg, respectively, as a single oral dose and repeated for 5 and 18 days. After the last dose (or a single dose) of Acetylsalicylic acid

At 213 Β minutes, the mice were placed in cylinders 10 cm in diameter, 25 cm in height and filled with water up to 6 cm. The water temperature was 21-22 ° C. The animals were observed for 5 minutes (from the end of the first minute after insertion to 6 minutes). The number and duration of interruptions (immobilization) during swimming were monitored. The results are shown in Table 1.

The compound of formula (I) significantly reduces the duration of immobilization during swimming. After a single administration, doses of 2.5 and 5 mg / kg had a 10-fold effect, and after 5 or 18 days, the compound reduced immobilization at a dose of 1 mg / kg.

Single-dose administration of pyrazidol produces only the same effect at a dose of 25 mg / kg, and at repeated doses 10 mg / kg is the effective dose. Imipramine was effective at single doses of both 10 mg / kg and 25 mg / kg. The effect of Imipramine was better with repeated administration, but no significant difference was seen between 5 days and 18 days.

From the above results it can be seen that the compound of the present invention exhibits a protective effect expressed in the Porsolt Emotional Stress Test, within which it reduces the inhibition of the animal and the associated immobilization. In this study, it was effective at doses 10 times lower than Imipramine and Pyrazidol.

Table 1

Effect of the compound of the invention, Pyrazidol and Imipramine on immobilization time measured in a float test

Treatment Dose in mg / kg p.o. Immobilization in seconds with single dosing number of mice time (sec) % Dist. water - 80 158 + 8.6 100 Compound of Formula (I) 1.0 30 145 ± 10.4 92 2.5 30 111 ± 9.9 ^XXX 69 5.0 40 105 ± 8, l ^xx 63 Dist. water - 40 176 ± 6.5 100 Pyrazidol 10.0 40 164 ± 5.9 93 25.0 40 144 + 9 _t 9 ^xxx 82 Dist. water - 30 153 ± 7.2 100 imipramine 10.0 30 131 ± 5.6 ^XX 88 25.0 30 107 ± 6.8 ^X 70

Continuing Table 1, the same parameters are given for multiple dosing (5 days or 18 days). 30 animals were dosed per dose in the 5-day experiment and 20 animals per dose in the 18-day experiment.

Continuation of Table 1:

Treatment Immobilization in seconds, respectively. %-in 5 days 18 days time (sec) % time (sec) % Dist. water 166 ± 9.9 100 184 ± 7.8 100 Compound of Formula (I) 102 ± 8, l ^x 61 107 ± 8.0 ^x 58 102 ± 6, l ^x 61 96 ± 11.0 ^x 52 88 ± 5.2 ^X 53 75 ± 9.8 ^X 41 Dist. water 163 ± 7.2 100 184 ± 7.8 100 Pyrazidol 142 ± 5.7 ^XXX 87 129 ± 8.0 ^x 70 116 ± 8, l ^x 71 112 ± 8.6 ^X 61 Dist. water 157 ± 5.9 100 184 ± 7.8 100 imipramine 92 ± 5.9 ^X 59 96 ± 9.8 ^X 52 61 ± 6.3 * 39 66 ± 9.8 36

Statistical safety of deviation from control: P <0.001 for x), P <0.02 for xx) and P <0.05 for xxx).

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The effect of the compound of formula (I) on reserpine-depressant effects (blepharoptosis, hypothermia, etc.) was also investigated.

White mice of both sexes, 16-18 g of body weight, were used for the experiments. The compound of formula (I) was p.o. dosing. Single doses of 1, 2, 5 and 5 mg / kg were used. In both the single dose and the last dosing in the 18 day experiment, a

This was done 60 minutes before the intraperitoneal administration of a 2.5 mg / kg reserpine dose. Here again, Pyrazidol and Imipramine were used as reference. The degree of blepharoptosis was determined according to the four-point system of Rubin et al. (1957) 4 hours after reserpine administration, because the diprimating effect of reserpine reaches its maximum at this time (Cheli et al., 1954). The results of this study are summarized in Table 2 below.

Table 2

Effect of Compound of Formula I, Pyrazidol and Imipramine on Reserpine-Induced Blepharoptosis in Mice

Treatment Dose in mg / kg Single dose 18 day experiment number of animals degree of blepharoptosis % number of animals degree of blepharoptosis % water, water - 60 3.2 + 0.18 100 30 3.5 ± 0.09 100 Compound of formula (I) 0.5 10 2.6 ± 0.21 * 65 1.0 24 2.2 ± 0.18 * 66 10 1.1 ± 0.32 * 31 2.5 30 0.6 ± 0.18 * 17 30 0.4 + 0.09 * 10 5.0 24 0.3 ± 0.18 * 9 10 0.1 + 0.21 * 2.5 Pyrazidol 10.0 84 2.3 ± 0.14 * 69 6 0.7 + 0.35 20 25.0 72 1.7 ± 0.18 * 51 12 0.5 + 0.18 * 14 imipramine 10.0 66 1.9 ± 0.14 * 58 12 0.7 + 0.18 * 20 25.0 60 1.2 ± 0.14 * 36 6 0.5 + 0.35 * 14

Statistical safety of deviation from control: x) P <0.01.

The data show that the antirezerpine effect of the compound of formula (I) is significantly (at least one order of magnitude) greater than that of Pyrazidol in both acute and chronic conditions, and outperforms Imipramine in efficacy.

The effect of the compound of formula (I) on d, lamphetamine (stereotype, hyperactivity, etc.) was also investigated.

To investigate the effect on stereotype, white rats of either sex, 100-150 g, were treated orally with Compound (I), Pyrazidol or Imipramine 60 minutes prior to the 5 mg / kg d, 1 amphetamine subcutaneous administration. Stereotype was evaluated at 0, 1, 2, 3 degrees by Janssen et al. (1967) (Table 3).

Studies have shown that the compound of formula (I) enhances stereotype and is close to the two reference substances in terms of potency.

The effect of d, I-amphetamine-induced hypermobility on male white mice weighing 20-22 g was investigated. The compound of formula I, Pyrazidol and Imipramine p.o. was administered 60 minutes prior to intraperitoneal administration of 2.5 mg / kg of d, l-amphetamine. From 10 minutes to 20 minutes after d, 1-amphetamine administration. motor activity in mice. The results are shown in Table 4.

Table 3

Enhancement of d, l-amphetamine-induced stereotype in rats (stereotype was measured 4 times 4 hours after d, l-amphetamine 5 mg / kg) __.__-_, _

Treatment Dose mg / kg Animals number Degree of stereotype % Dist. water - 60 2.8 ± 0.14 100 Compound of formula (I) 2.5 10 4.0 ± 0.28 * 145 5.0 30 4.8 ± 0.14 * 170 10.0 40 6.3 ± 0.14 * 225 Pyrazidol 5.0 50 4.6 + 0.14 * 165 10.0 45 5.9 ± 0.14 * 210 imipramine 5.0 30 5.6 ± 0.14 * 200 10.0 ¹⁵ 8.6 ± 0.23 * 306

Statistical safety of deviation from control horse: 60 x) P <0.001.

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Compounds of formula (I) potentiate the hyperlocomotor effect of d, 1-amphetamine at doses of 1.0, 2.5, and 5.0 mg / kg. Pyrazidol and Imipramine did not increase the effect of d, 1-amphetamine in similar experiments.

Table 4

Effect of the compound of formula (I), Pyrazidol and Imipramine on the hyperlocomotor effect induced by d, l-amphetamine in mice (mean values of groups of 5 animals)

Treatment Dose mg / kg Groups number Mean value of motor activity Dist. water - 20 1924.5 ± 177.6 Compound of Formula (I) 1.0 12 3482.6 ± 445.5 * 2.5 10 3315.5 ± 462.6 ^XX 5.0 10 4885.0 ± 537.2 ^XX Pyrazidol 5.0 10 1440.0 ± 380.2 10.0 10 1926.0 ± 119.9 Imiprami- not 5.0 12 1440.3 ± 365.2 10.0 12 2024.5 ± 221.7

Statistical safety of deviation from control: P <0.01 for x), P <0.02 for xx).

The potentiating effect of the compound of formula (I) on d, l-amphetamine-induced stereotype and hyperactivity reflects the potentiation of adrenergic and dofaminergic processes in the brain.

We further investigated the effect of the compound of formula (I) on 5-hydroxytryptophan irritation (head twitches). The experiments were carried out with white mice of both sexes weighing 16-20 g, according to the method of Come et al. (1963).

Compounds of formula (I) were administered orally at doses of 1.0, 2.5, 5.0 and 10 mg / kg 60 minutes prior to intraperitoneal administration of 5-hydroxytryptophan 50 mg / kg. At this dose, 5-hydroxy-tryptophan does not cause convulsions in mice, however, the compound of formula (1) or Pyrazidol did show development in some animals.

To assess the effect, the number of mice that exhibited at least one jerk every 25 minutes after administration of 5-hydroxytryptophan was calculated and the EDjq dose, which caused a jerk in 50% of the animals, was calculated. In this experiment, the compound of formula I has an ED ™ of 2.5 (2.1-3.0) mg / kg p.o. of Pyrazidol was 20 (14-28) mg / kg p.o.

From this it can be concluded that the compound of formula (I) enhances the seizure activity of 5-hydroxytryptophan in mice much more efficiently than Pyrazidol (about eight times the level), suggesting that the compound of formula (I) is serotonergic in excess of Pyrazidol. effect.

Based on its ability to enhance the seizure activity of 5-hydroxytryptophan, the compound of formula (I) has a monoamine oxidase inhibitory activity. Therefore, the effect of the compound of formula (I) on the activity of monoamine oxidase was investigated by special biochemical experiments.

Studies in this regard were performed on male white rats weighing 180-200 g. The compound of formula (I) was administered orally at doses of 5, 10, 25 and 50 mg / kg, respectively. The control animals were treated with an equal volume of 0.9% saline. 1.5 hours after drug administration, the animals were sacrificed. In a parallel experiment, the durability of the effect was tested by 25 mg / kg p.o. animals were sacrificed at different times (1.5.6 and 48 hours) after dosing. Monoamine oxidase activity was assayed in homogenized liver and brain tissue samples. The sample was diluted with an equal volume of 0.1 M phosphate buffer, pH 7.4; the buffer contained 2% Tritol Χ-100 as a detergent. The concentrations of the substrates in the samples were as follows; serotonin; 10 gm, Thyramine: 6 pmol. Monoamine oxidase activity was determined by the amount of ammonia released during incubation at 37 ° C in an oxygen atmosphere for 50 minutes.

Protein content of homogenized liver and brain tissue samples was determined according to Peterson's method (Peterson, 1977). The compound of formula (I) has been shown to have a significant monoamine oxidase inhibitory activity over Pyrazidol.

However, the monoamine oxidase inhibitory activity of the compound of formula I differs from that of Pyrazidol monoamine oxidase in terms of substrate and tissue selectivity: the compound of formula (I) inhibits the oxidative deamination of serotonin more than thyraminate, and monoamine oxidase in the brain like the liver. The monoamine oxidase inhibitory effect is already apparent at a dose of 5 mg / kg and increases with dose. Substrate selectivity remains complete at increasing doses in the liver, whereas in the brain this selectivity is reduced. The results are summarized in Table 5.

Table 5

Influence of compound of formula (I) on oxidative deamination of monoamines (on homogenized rat brain and liver samples)

The dose of the compound of formula (I) is mg / kg p.o. Percent inhibition of deamination Brain Liver serotonin tyramine serotonin tyramine 5 60 ± 6.3 17 ± 4.2 36 ± 9.0 0 10 61 ± 7.6 16.6 ± 3.4 27 ± 6.7 0 25 71 ± 7.6 40 ± 3.0 64 ± 6.4 0 50 93 ± 3.0 43 ± 6.6 89 ± 2.7 0

From the table, the compound of formula I exhibits a selective monoamine oxidase inhibitory activity at a lower dose (5 mg / kg) which is more potent in the brain than

HU 206 213 Β in the liver. In the brain, the compound noticeably (60%) inhibits the deamination of serotonin, and much less inhibits thyamine. Increasing the dose (up to 50 mg / kg) also increases the inhibitory effect on type A monoamine oxidase.

In rats, the difference between serotonin and thyramine deamination is maintained at both 5 mg / kg and 50 mg / kg. None of the tested doses of the compound had an effect on hepatic deamination of thyramine.

At the 25 mg / kg dose, the above-mentioned experiment demonstrates that the effect is maximal at 1.5 hours post-dose, with 6 hours of deamination of serotonin and thyramine mainly in the brain and liver. and after 48 hours, monoamine oxidase activity is completely restored.

The results of the study are shown in Table 6,

Table 6

The compound of formula (I) exhibits a monoamine oxidase inhibitory activity of 25 mg / kg p.o. dose (in rat liver and brain tissue)

time clock % Inhibition of deamination Brain Liver serotonin tyramine serotonin tyramine 1.5 71.0 + 2.0 40.0 ± 3.0 64.0 + 6.4 0 6.0 66.5 ± 3.0 36.0 + 9.3 53.0 ± 3.0 0 48.0 14.0 + 4.8 2.5 + 1.1 0 0

When pyrazidol is administered, monoamine oxidase activity is restored in the brain after 24 hours and in the liver after 6 hours.

It is seen that the monoamine oxidase inhibitory activity of the compound of formula (I), like Pyrazidolene, is constant and reversible; mainly concerns type A monoamine oxidase.

The effect on brain bioelectric activity was studied in 8 non-anesthetized Dipplatin-treated cats weighing 2.5-3.4 kg and in 25 rabbits (2.6-3.1 kg) with controlled breathing using electrodes permanently implanted. In addition to electroencephalography, pulses out of the reticulum of the midbrain, the posterior hippocampus, and the tonsil were recorded in addition to the electroencephalogram of the sensory motor, visual and midbrain cerebral cortex.

Compounds of formula (I) did not alter the bioelectric activity of the cerebral cortex and subcortical brain structure at doses of 0.5 and 1 mg / kg (i.p. or i.v.). At a dose of 2.0 mg / kg in cats, acceleration in the rhythm of the biopotentials was observed up to 20-25 / sec, the amplitude of the oscillation decreased to 25-40 μV (in the control, the oscillation frequency was 8-10 sec, the amplitude was 90-120 was), that is, in every recorded part of the cortex. Even in rabbits, increased rhythm and decreased amplitude were observed in the sensory region of the cerebral cortex, whereas low-amplitude, 5-7 / sec. Theta-like activity was observed in the hippocampus: sinusoidal, 4-6 / s frequency, 150-200 μν amplitudes. These changes in the encephalogram were observed 75-90 minutes after drug administration. At 5 mg / kg, the effect of the compound was similar to that seen at 2 mg / kg, but was more rapid at 45-60 minutes after administration. However, the activation of the encephalogram induced by the compound of formula (I) was interrupted by periods of waves of different amplitudes and frequencies, typical of control background noise. In general, there was no continuous activation.

At a dose of 1-5 mg / kg i.v. administration of pyrazidol also activates the encephalogram of the cerebral cortex and subcortical bed structures.

Tricyclic antidepressants (Imipramine, Amitriptylin) exert a synergistic effect against the compound of formula (I) and Pyrazidol, and their activity in the encephalogram is dominated by slow-amplitude activity.

The effect of the compound of formula I on the recovery of memory loss (amnesia) was also investigated. The studies were performed on male rats weighing 180-200 g.

The effect of memory loss was investigated by eliciting a conditional reflex of passive avoidance followed by an amnesia-inducing agent (50mA, 0.3 milliseconds, electroshock applied to the ear electrode, or scopolamine 1 mg / kg subcutaneously).

The conditional reflex of passive avoidance was developed by the step-down method (Izquerdo, 1981). The experimental apparatus consisted of a 30 x 30 x 40 cm ³ chamber with a tensioned floor. In the center of the chamber was a 10x15x0.5 cm plastic stand. The rat was placed on the stand and the number of seconds to leave the stand was measured. Walking to the floor, the rat received an electrical stimulus (0.5 mA, 10 inp) in the paw causing it to run back onto the stand. The learning process consisted of 6 lessons of 3 minutes each. A conditional reflex was considered to be formed if the animal did not leave the stand within 1 minute.

Amnesia was induced immediately after the learning process, and 30 minutes later, compounds of formula I were dosed at 1 and 3 mg / kg, respectively, and Pyrazetam at 100, 300, 600, and 1000 mg / kg, respectively. Memory recovery was assessed 24 hours after electroshock and 2.5 hours after scopolamine administration.

The results obtained are summarized in Table 7.

The table shows that the compound of formula (I) at a dose of 3 mg / kg significantly increases the number of animals in which passive avoidance is avoided.

His reflex weakened due to electroshock or scopolamine, but later recovered. Pyrazetam exerts a similar effect only at 1000 mg / kg.

The corrective action of the compound of formula (I) on amnesia-damaged imprinting suggests the nootropic properties of the compound.

Table 7

The effect of the compound of formula (I) and Pyrazetam on the restoration of the conditional reflex of passive avoidance (anti-amnesic effect). (20 rats were dosed per dose for test compound and 10 for Pyrazetam.)

Treatment Dose mg / kg % Of rats on the stand for 1 minute,% 1 day after electroshock after administration of scopolamine 2.5 hours Dist. water - 85 + 2.0 85 ± 2.0 electroshock 14.2 ± 3.0 10 ± 3.3 Compound of the formula 1 + electroshock 1 25 ± 3.2 22 ± 6.0 3 40 ± 6.0 * 33 ± 4.4 * Pyramid + electric shock 100 12 ± 3.3 12 ± 5.5 300 13 ± 4.2 13 ± 1.6 600 12 ± 3.3 20 ± 5.5 1000 46 ± 6.4 52 ± 2.0 *

Statistical safety of deviation from control: x) P <0.001.

The effect of the compound on the cardiovascular system was also examined. In Wister rats with normal blood pressure (280-300 g), the compound of formula (I) had no significant effect on arterial blood pressure and heart rate at doses of 1-100 mg / kg (arterial blood pressure at the tail, 1, 3 and 6 hour). The compound was administered to rats at 10 mg / kg / day for 5 days, with no change in heart rate on day 1 or subsequent days.

An important criterion for the safety of drugs is their effect on the thyramine effect of the pressor.

The studies were performed on Wister rats with normal body weight and weighing 210-250 g; the animals were free to move. Thyramine was administered orally at a dose of 20 mg / kg, 1, 3.6, 18 and 24 hours after administration of the compound of formula (I). To the control, no control group was given Moclobemide, which is an antidepressant and a reversible monoamine oxidase type A inhibitor. It has been found that the compound of formula I (like the same dose of Moclobemide) at a dose of 25 mg / kg p.o. doubles the effect of thyramine pressor. The increase occurs 6-18 hours after administration of the compound of formula (I).

When the compound of formula I is administered at a dose of 5 mg / kg p.o.

administered for 5 days, there is no enhancement of the effect of thyramine. In contrast, moclobemide enhances the effect of the thyroid pressor at a single dose of 5 mg / kg.

The central and peripheral anticholinergic activity of the compound of formula (I) was further investigated. The compound was administered at doses of 10 and 25 mg / kg p.o., and 1, 2 and 5 mg / kg i.v. it did not alleviate the convulsions and fever caused by oxotremorine, did not reduce the intensity and duration of the hyperecinesis of arecoline, nor did it decrease the stimulatory effect of galantamine on one of its bioelectric activity. This demonstrates that the compound of formula (I) has no anticholinergic activity.

The acute and chronic toxicity of the compound of formula (I) was investigated in mice, rats and rabbits. Studies have shown that the compound of formula (I) is only slightly toxic: LD _{50 is} 1300 mg / kg in mice and 2500 mg / kg in rats.

The compound of formula (I) was administered daily for 6 months and no impairment of the function of the internal organs of the animals was observed. The drug has no significant effect on the central nervous system and the cardiovascular system, and does not change the morphological and biochemical blood parameters. At a dose of 10-50 mg / kg / day (2 to 10 times the expected therapeutic dose), no morphological changes were observed, 100 mg / kg (20 times the therapeutic dose) did not cause any specific pathological changes in the organs which, however, proved to be reversible. One month after dosing, the test animals did not show any pathological changes in the viscera.

The potential mutagenic effects of the compound of formula (I) were also investigated in the Drosophila gene mutation, the lethal dominant mutation of embryonic rat cells, the chromosomal degeneration of mouse bone marrow cells, and in human lymphocytes. None of the tests was mutagenic in the compound of formula (I).

The carcinogenicity of the compound of formula (I) was tested in long-term studies in mice and rats with negative results. The compound was neither allergenic, nor embryotoxic, nor teratogenic.

The preparation of 2,3,3a, 4,5,6-hexahydro-8-cyclohexyl-1 H -pyrazino [3,2,1-j, k] carbazole hydrochloride of the formula I according to the invention is illustrated in Scheme A.

6-Cyclohexyl-4,5-dihydrocarbazole (2H) -one (II) is alkylated with P- (N, N-dibenzylamino) ethyl chloride hydrochloride (III) from an aromatic hydrocarbon (e.g., chlorobenzene, toluene) and the like. In a two-phase system consisting of -40% by weight alkali metal hydroxide solution at 85110 ° C in the presence of a phase transfer catalyst.

Examples of phase transfer catalysts include tetraalkyl or trialkylbenzyl or trialkyl (alkylbenzyl) ammonium halides such as tetrabutylammonium bromide, triethylbenzylammonium chloride, benzyl chloride and triethylamine or dimethylamine or dimethylamine or dimethylamine. . The resulting 6-cyclohexyl-9- [2- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbanzol-1 (2H) -one of formula (IV) is formed on a carrier such as activated carbon or a non-combustible carrier, like asbestos

HU 206213 Β in the presence of a palladium catalyst. The hydrogenation medium used is lower alcohol. The hydrogenation is carried out at 50-70 [deg.] C. and a pressure of 1-30 [mu] l. Preferably the catalyst is palladium bis (acetylacetonate) or palladium hydroxide on activated carbon or asbestos. In the case of palladium-carbon bis (acetylacetonate), the hydrogenation is preferably carried out at 50-60 ° C under a pressure of 10-12 atoms. The resulting 2,3,3a, 4,5,6-hexahydro-8-cyclohexyl-1H-pyrazino [3,2,1-j, k] -carbazole is converted to the hydrochloride and isolated as such. The yield of the final product is 70-75% by weight of the starting compound (II).

The invention will now be further illustrated by the following embodiments.

Example 1

To a mixture of 100 ml of toluene and 100 ml of 30% aqueous sodium hydroxide solution was added 20 g of 98% (0.0733 mol) of 6-cyclohexyl-3,4-dihydrocarbazol-1 (2H) -one [II]. The mixture was stirred for 5-10 minutes and then 27.75 g of 96% (0.0899 mol) of 2- (N, N-dibenzylamino) ethyl chloride hydrochloride and 0.4 g of tetrabutyl ammonium bromide was added. The mixture was stirred and heated at 103-106 ° C for 15-16 hours. After completion of the TLC-controlled reaction, the phases are separated, the aqueous phase is extracted with toluene and the toluene extract is added to the main toluene fraction. The toluene was removed in vacuo and the residue was dissolved in 100 ml of anhydrous ethanol with heating. The crystalline precipitate which formed upon cooling was filtered, washed with cold anhydrous ether (15 ml) and dried.

34.0 g (94.52%) of substantially pure 6-cyclohexyl-9- [2- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbazol-1 (2H) -one are obtained in the form of light yellow crystals.

Mp 103-104 ° C (recrystallized from ethanol, m.p.

104-105 ° C).

Analysis: Calculated for C ₃₄ H ₃₈ N ₂ O: C, 83.22; H, 7.81; N, 5.71; Found: C, 83.55; H, 7.90; N, 5.64.

IR spektrunrv _co = 1650 cm- ^first

UV spectrum (alcohol): λ nm (Ig E): 241.9 (4.27);

314.7 (4.34).

A suspension of 6-cyclohexyl-9- [2- (N, N-dibenzylamino) -ethyl] -3,4-dihydrocarbazol-1 (2H) -one (0.0204 mol) in methanol (2 ml) was treated with 5 g of 5% methanol. in the presence of palladium on carbon (palladium on carbon precipitated on carbon) under hydrogen at 10 [deg.] C. until hydrogen uptake ceases. Hydrogen uptake is generally the same as theory. The catalyst was filtered off and the filtrate was acidified to pH 1-2 with concentrated hydrochloric acid (3-4 mL). After cooling, the precipitate was filtered off, washed with acetone and dried.

5.75 g (80.66% of starting material of formula II) of technical purity 2,3,3a, 4,5,6-lexahydro-8-cyclohexyl-1H-pyrazino [3.2, lj, k] Carbazole hydrochloride is obtained in the form of white crystals with a slightly yellowish tinge. Recrystallization from aqueous methanol gave 5.25 g (73.65% of the starting material) of the hydrochloride.

UV spectrum: nm (1g E): 229.5 (4.651), 276.7 (3.123).

Mass Spectrum: m / z M ⁺ 330.9.

1 H-NMR (chemical shift, ppm). H, 4.15; H-2

4.38; H-4, 3.12; H-5, 3.02; H-6 2.29; H-7 7.58; H-9

7.49; H, 10.49; H-1 '262; H-2 ', H-3', H-4 ', 1.21,9 ppm.

Example 2

To a mixture of 100 ml of toluene and 100 ml of 30% aqueous sodium hydroxide solution is added 20 g of 98% (0.0733 mol) of 6-cyclohexyl-3,4-dihydrocarbazol-1 (2H) -one, After stirring for 10 minutes, 27.75 g of 96% (0.0899 mol) of P- (N, N-dibenzylamino) ethyl chloride hydrochloride and 0.4 g of triethylbenzylammonium chloride are added. . The procedure described in Example 1 was followed. 34.35 g (95.5%) of 6-cyclohexyl-9- [2- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbazol-1 (2H) -one are obtained, m.p. 103-104 ° C. are.

A suspension of 6-cyclohexyl-9- [2- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbazol-1 (2H) -one (0.0204 mol) in methanol (60 mL) was treated with palladium (0.35 g). hydrogenated in the presence of bis (acetylacetonate) and 2.5 g of activated carbon at a pressure of 20 at 50 ° C. After completion of the reaction, the catalyst is filtered off and the filtrate is acidified to pH 1-2 with concentrated hydrochloric acid. After cooling, the precipitate is filtered off, washed with acetone and dried. 5.87 g (83.17% of starting compound II) of technical purity 2,3,3a, 4,5,6-hexahydro-8-cyclohexyl-1 H -pyrazino [3,2,1] k] carbazole hydrochloride are obtained. . Recrystallization from aqueous methanol afforded 5.12 g (72.54%) of 2,3,3a, 4,5,6-hexahydro-8-cyclohexyl-1H-pyrazino [3,2.1j, k] carbazole hydrochloride. The physical data of the product is as in Example 1.

Example 3

To a mixture of 100 ml of chlorobenzene and 100 ml of 40% aqueous sodium hydroxide solution was added 20 g of 98% (0.0735 mol) of 6-cyclohexyl-3,4-dihydrocarbazol-1 (2H) -one [Compound II] After stirring for 5-10 minutes, 27.75 g of 96% (0.0899 mol) of P- (N, N-dibenzylamino) -ethyl chloride hydrochloride, 0.5 ml of benzyl chloride and Triethylamine (6 mL) was added. The reaction is carried out as described in Example 1 at the boiling point of the mixture for 5-6 hours.

34.73 g (96.55%) of 6-cyclohexyl-9- [2- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbazol-1 (2H) -one are obtained, m.p. 103-104 ° C. are.

A suspension of 6-cyclohexyl-9- [2- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbazol-1 (2H) -one (0.0204 mol) in methanol (60 ml) was treated with palladium bis (0.35 g). acetylacetonate) and 2.5 g of activated carbon are hydrogenated at 60 DEG C. under 1-3 at. After completion of the reaction, the catalyst is filtered off and the filtrate is acidified to pH 1-2 with concentrated hydrochloric acid. After cooling, the precipitate was filtered off, washed with acetone and dried to give 5.75 g (82.37% of the starting compound II) of technical purity.

HU 206 213 Β. Recrystallization from aqueous methanol gives 5.20 g (74.49%) of 2,3,3a, 4,5,6-hexahydro-8-cyclohexyl-1H-pyrazino [3,2,1-j, k] carbazole hydrochloride. The physical data of the product is as in Example 1.

Example 4 To a mixture of 100 ml of toluene and 100 ml of 40% aqueous sodium hydroxide solution is added 20 g of 98% (0.0735 mol) of 6-cyclohexyl-3,4-dihydrocarbanzol-1 (2H) -one. , the mixture was stirred for 5-10 minutes, followed by 27.75 g of 96% (0.0899 mol) of P- (N, N-dibenzylamino) ethyl chloride hydrochloride, 1 ml of benzyl chloride and 1.2 ml. of dimethylformamide was added. The procedure described in Example 1 was followed. 34.21 g (95.1%) of 6-cyclohexyl-9- [2- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbazole (2H) -one are obtained, m.p. 103-104 ° C. melted. In the following, the procedure of Example 1 is followed. 5.76 g (81.27% of starting material of formula II) are obtained in the technical grade. Recrystallization from aqueous methanol 5.09 g [71.82% of starting material II] 2,3,3a, 4,5,6-hexahydro-8-cyclohexyl-1H-pyrazino [3,2,1- jcarbazole hydrochloride is obtained. The physical data of the product is as in Example 1.

Example 5

To a mixture of 100 ml of toluene and 100 ml of 30% aqueous sodium hydroxide solution is added 20 g of 98% (0.0733 mol) of 6-cyclohexyl-3,4-dihydrocarbazol-1 (2H) -one, After stirring for -10 minutes, 27.75 g of 96% (0.0899 mol) of P- (N, N-dibenzylamino) ethyl chloride hydrochloride and 1 ml of polyethylene glycol are added. The procedure of Example 1 was followed. 34.0 g (94.52%) of 6-cyclohexyl-9- [2- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbazol-1 (2H) -one are obtained. ° C. The product was further reacted as described in Example 1.

Example 6

To a mixture of 100 ml of toluene and 100 ml of 30% aqueous sodium hydroxide solution was added 20 g of 98% (0.0735 mol) of 6-cyclohexyl-3,4-dihydrocarbazol-1 (2H) -one, After stirring for -10 min, 27.75 g of 96% (0.0899 mol) of P- (N, N-dibenzylamino) ethyl chloride hydrochloride and 1.5 ml of 50% dimethyloctylbenzylammonium were added. chloride is added. The procedure described in Example 1 was followed. 34.69 g (96.43%) of 6-cyclohexyl-9- [2- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbazol-1 (2H) -one are obtained. ° C. The product was further reacted as in Example 1.

Example 7

To a mixture of 200 ml of chlorobenzene and 90 ml of aqueous sodium hydroxide solution was 40.92 g of 98% (0.15 mol) of 6-cyclohexyl-3,4-dihydrocarbazol-1 (2H) -one, 53.59 g of 99, 5% (0.18 mol) p- (N, N-dibenzylamino) ethyl chloride hydrochloride, 1.5 ml benzyl chloride and 1.5 ml triethylamine were added. The reaction was carried out as in Example 1, but the product (IV) was isolated from methanol, 72 g [96.26% of starting material II] 6-cyclohexyl-9- [2- (N). N-dibenzylamino) ethyl 1 - 3,4-dihydrocarbazol-1 (2H) ontone (IV) is obtained.

A suspension of 20.33 g (0.0408 mol) of 6-cyclohexyl-9- [2- (N, N-dibenzylamino) ethyl] -3,4-dihydrocarbazol-1 (2H) -one in 150 ml of methanol was added. , Hydrogenated in the presence of 4 g of palladium bis (acetylacetonate) and 4 g of activated carbon at 1020 at 60 ° C. After completion of the reaction, the catalyst is filtered off, washed with methanol and the filtrate combined with the washing liquid is acidified to pH 1-2 with concentrated hydrochloric acid. After cooling, the precipitate was filtered off, washed with acetone and dried.

11.82 g (84.35% of the starting material of the formula II) of the technical grade are obtained, which are recrystallized from aqueous methanol. 10.74 g (76.65% of compound of formula II) are obtained: 2,3,3a, 4,5,6hexahydro-8-cyclohexyl-1H-pyrazino [3,2,1-j, k] carbazole hydrochloride. The physical data of the product is as in Example 1.

Claims (3)

PATENT CLAIMS A process for the preparation of 2,3,3a, 4,5,6-hexahydro-8-cyclohexyl-1H-pyrazino [3,2.1-j, k] carbazole hydrochloride of the formula I, characterized in that 6-cyclohexyl-3,4 -dihydrocarbazol-1- (2H) -one with 3- (N, N-dibenzylamino) ethyl chloride in a two-phase system consisting of aromatic hydrocarbon and 3040% aqueous alkali metal hydroxide solution as phase transfer catalyst, tetraalkyl or trialkyl Benzyl or trialkyl (alkylbenzyl) ammonium halide is alkylated at 85-110 ° C using a mixture of benzyl chloride and triethylamine or diethylformamide or polyethylene glycol to give 6-cyclohexyl-9- [2- ( N, N-Dibenzylamino) ethyl] 3,4-dihydrocarbazol-1- (2H) -one is hydrogenated in the presence of a palladium catalyst on a lower aliphatic alcohol at 50-70 ° C at a pressure of 1-30 at The hydrochloride from 3,3a, 4,5,6-hexahydro-8-cyclohexyl-1H-pyrazino [3,2,1j, k] carbazole is formed and the salt is isolated. The process according to claim 1, wherein the palladium catalyst is palladium bis (acetylacetonate) or palladium hydroxide and the carrier is carbon or asbestos. 3. A process according to claim 1 wherein the palladium catalyst is palladium bis (acetylacetonate) supported on carbon and the hydrogenation is carried out at a pressure of 10-20 at a temperature of 50-60 ° C.