CH625240A5 - Process for preparing novel derivatives of vincamine and apovincamine - Google Patents

Abstract

For producing derivatives of vincamine or apovincamine, the starting material is vincamine or apovincamine respectively in the form of a solution or suspension. This solution or suspension is reacted with a solution of glucose 1-phosphate, glucose 6-phosphate or, respectively, 2,4-dihydroxybenzoic acid. In this way, derivatives of vincamine and apovincamine are prepared which belong to the classes of the glucose 1-phosphate, glucose 6-phosphate and of resorcylate. These novel derivatives have therapeutic properties which are of interest at the cardiovascular level and on the circulation system in general.

Description

The present invention relates to a process for the preparation of new vincamine and apovincamine derivatives having interesting therapeutic properties at the cardiovascular level and, in general, of the circulatory system.

The vincamina, having formula

CH.OOC C0H_

OR 4 D

(the)

45 The general process for the preparation of the compounds in question involves reacting vincamine or apovincamine according to the desired salt, in the form of a solution or suspension in a suitable solvent and when hot, in contact with acid 2,4- dihydroxybenzoic acid or with a solution of glucose-1-phosphate or glucose-6-phosphate, keeping the reaction mass under stirring until the reaction has taken place, after which it is concentrated, eliminating by filtration the excess vincamine or excess apovincamine which separates and then the desired salt is crystallized. 55 The particular aspects and details of the preparation of the new compounds according to the present invention will clearly appear from the following examples, having an illustrative but not limitative purpose. The examples refer in particular to glucose-1-phosphate but substantially identical are the operating conditions for the glucose-6-phosphate derivatives.

65

Example 1 Vincamine glucose-1-bisodic phosphate

In this case it is an equimolecular adduct, (C:, 1H2i; N203. CuH11Na, 09P) having formula

CH2OH

H OH

3.54 g (10 ~ 2 moles) of vincamine are dissolved in a mixture of 180 ml of ethyl alcohol and 25 ml of CHC13, hot (70 ° C) on a water bath and under stirring.

A solution consisting of 3.76 g (IO-2 moles) of glucose-1-phosphate disodium salt tetra-hydrate (CGH11Na209P. 4H20) in 20 ml of water is added dropwise.

The reaction mass is kept hot under stirring for 30 minutes and then concentrated in full to a final volume of about 50 ml.

Another 60 ml of alcohol are added and the solvent is distilled off to a residue.

This operation is repeated a second time, ultimately reaching a final volume of about 10 ml.

The precipitation is completed, leaving the mixture to rest in an ice bath.

After filtering and drying the product in a ventilated oven at 60 ° C, 7.2 g of a white and crystalline substance, insoluble in water and in alcohol, are obtained, having a total melting point of about 240 ° C.

The vincamine dosage in the adduct is 55%. The above procedure is repeated, varying only the ratios of the two reagents, which are respectively 2.5 g of vincamine and 7.5 g of glucose-1-phosphate bisodic salt tetra-hydrate.

9.8 g of a product identical to the previous one are obtained, with a titer of 26%.

15

20

30

35

Example 2 Apovincamine glucose-1-disodium phosphate

40

CHJDOC

3 C H

U2n5

CHgOH

C21H24N.2O2

0 n <-W +>

„^ 0 Na ■ P ^ (-) (+) ^ -Cr Na

C0H11Na2O9P

The procedure of Example 1 is repeated, except that the adduct is prepared from 3.36 g (IO-2 moles) of apovincamine and from 3.76 g of glucose-1-phosphate disodium salt tetrahydrate.

7 g of a white, crystalline substance insoluble in water and alcohol and having a complete melting point of about 160-165 ° C are obtained.

The dosage of apovincamine in the adduct is 53.1%. The above procedure is repeated, varying only the ratios of the two reagents, which are respectively 2.5 g of apovincamine and 7.5 g of glucose-1-phosphate disodium salt tetra-65 hydrate.

9.8 g of a product identical to the previous one are obtained, with an apovincamine titre of 26%.

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4

Example 3

Vincamine 2,4-dihydroxy-benzoate (vincamine ß-resorcylate)

COOH

CH300C C2H5

C28tL, 2N207 P.M. = 508.6

A suspension of 7.08 g (2.10-2 moles) of vincamine in 100 ml of ethyl alcohol is prepared in a suitable container equipped with a stirrer, reflux cooling column and loading funnel. The mixture is heated to reflux under stirring and the gradual addition of a solution consisting of 3.08 g (2.IO-2 moles) of 2,4-dihydroxy-benzoic acid in a sufficient quantity of ethyl alcohol is started. The mass is kept at boiling for one hour and in the meantime about 50 ml of CHCIj are added, so as to obtain a homogeneous solution.

Then it is concentrated in small volume under reduced pressure and the precipitation of the salt is completed by diluting with diethyl ether. It is filtered on Büchner and dried in a ventilated oven at 50 ° C.

10 g of crystalline product are obtained, soluble in ethyl alcohol and having a melting point of 160-170 ° C. The dosage of vincamine in salt is 69%.

20

25

30

35

Example 4 Apovincamine 2., 4-dihydroxy-benzoate

COOH

CH 00C p "3 2 5

^ 28 ^ 30 ^ 2 ^ 6

P.M. = 490.54

6.73 g (2.10 2 moles) of apovincamine are dissolved in 55 100 ml of ethyl alcohol and subsequently added with 3.08 g (2.1 (h2 moles) of resorcylic acid (2,4-dihydroxy-benzoic acid) dissolved in the minimum amount of ethanol.

The mixture is kept under boiling under reflux for one hour and then concentrated to a small volume. 60

The precipitation of the product is completed by adding diethyl ether and cooling in an ice bath.

It is filtered on Büchner and dried at 50 ° C in a ventilated oven, obtaining 9.6 g of product with a melting point of 170-65 173 ° C, soluble in alcohol and insoluble in water and in common organic solvents. The dosage of apovincamine in salt is 65%.

Example 5 Vincamine glucose-1-phosphate ch3ooc

CH2OH

H

l / l

OH H

I HAVE

5.5 g of vincamine are suspended in a mixture of 250 ml of ethyl alcohol and 35 ml of CHCI3. The mixture is heated to 70 ° C on a water bath under stirring and an aqueous solution containing 2 g of glucose-1-phosphate is added dropwise. 25

The mixture was kept under stirring at 70 ° C for 30 minutes and then concentrated to a small volume under reduced pressure. The mixture is subsequently taken up with 2 X 200 ml of ethanol and then concentrated at a final volume of 80 ml.

Excess vincamine is removed by filtration, which separates and the filtrate is concentrated to 40 ml.

The solution is diluted until it becomes cloudy, then left to crystallize in the cold. After filtration and drying in a ventilated oven at 60 ° C, 5.2 g of vincamine glucose-1-phosphate are obtained which is presented in the form of 35 a white crystalline solid, partially soluble in water, with a melting point of 210 ° C ( dec.).

The dosage of vincamine in salt is 70.3%.

40

Example 6 Apovincamine glucose-1-phosphate k-t • \ °

OH ^ j-

CH20H

H

CH300C? 2H5

The procedure of the previous example is repeated, except that 6.7 g of apovincamine and 2.6 g of glucose-1-phosphate are used.

6.25 g of a white crystalline product, soluble in water and having a melting point of 155 ° C (de-comp.) Are obtained.

The dosage of vincamine in salt is 70%.

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6

Example 7 Vincamine glucose-1-acid phosphate

CH20H

OcOv • jtjj / LL »r: r

H0> JvJL J h oh ° h ch3ooc ^ J2h5

The procedure of Example 5 is repeated unless 3.8 g of vincamine and 3.1 g of glucose-1-phosphate are used.

5.8 g of a crystalline white product, soluble in water and having a melting point of 172 ° C are obtained.

The dosage of vincamine in salt is 58.6%.

Example 8 Apovincamine glucose-1-acid phosphate

This compound is prepared according to the method of the previous example, starting from 4.3 g of glucose-1-phosphate and 5.56 g of apovincamine.

5.7 g of white solid product, crystalline and soluble in water, with melting point of 162 ° C (dee.) Are obtained. The dosage of apovincamine in salt is 54%. The new derivatives obtained with the process of the present invention have been the subject of a pharmacological investigation, during which the following aspects were examined in particular, capable of highlighting not only the pharmacological activity at the brain level but also that it is of the type protracted effect.

The properties under investigation were the following:

- acute intraperitoneal toxicity;

- blood levels, urinary levels and intestinal levels at different times from oral treatment;

- change in blood flow to the carotid artery at times other than intravenous administration;

- influence on blood pressure.

A - Acute toxicity

Acute toxicity was determined in the mouse strain Swiss de! average weight of 20 g and male, using groups of 5 animals each, with the Litchfield and Wilcoxon method (observation time 8 days). The compounds were administered in 1% carboxymethylcellulose suspension.

Acute toxicity was low for all the compounds examined as shown in table 1, which also contains those of vincamine (HCl) and apovincamine.

P.M. = 596.6 TABLE 1

Composed

LD50 mg / kg i.p.

Type of tox

Vincamina HCl

800

modest

Ex. 1

2000

negligible

Ex. 3

750

modest

Ex. 5

1150

slight

Ex. 7

700

modest

Apovincamina

2000

negligible

Ex. 2

2000

slight

Ex. 4

650

modest

Ex. 6

850

modest

Ex. 8

600

modest

The results therefore demonstrate that the compounds are poorly toxic administered parenterally. In fact, for all compounds the toxicity evaluated according to the Gleason method can be classified as mild, moderate or negligible.

B - Absorption research.

All compounds were administered orally at a dose of 100 mg / kg, expressed as vincamine and apo-

./°H

pv

^ OH

7

62524 "

vincamine, in suspension in a 5% carboxymethyl cellulose solution.

Absorption was determined by evaluating blood levels at the following times: 0 ', 30', 120 ', 240', 480 ', 10 h and 12 h.

Urinary elimination was also determined at the following times: 24 h and 48 h.

To establish a possible delay in relation to intestinal absorption, intestinal percentage recoveries after 120 'and 480' from the administration of vincamine salts and after 120 'and 480' from the administration of apovincamine salts were also evaluated.

The dosages of vincamine and apovincamine were carried out by chromatographic method.

a) Vincamine salts

For the evaluation of the delayed action of vincamine salts, the following criteria were followed: delayed action derivatives are considered to be those derivatives which after 120 'from administration show blood levels higher than those obtained with vincamine.

Intestinal delay compounds are considered to be those salts which present after at least 120 'intestinal levels of vincamine in a statistical sense significantly higher than vincamine itself.

TABLE 2

Composed

Intestinal levels

Max conc. Time

Vincamina HCl

-

20 '

Ex. 1

-

570 '

Ex. 3

-

120 '

Ex. 5

-

240 '

Ex. 7

+

240 '

It is evident from table 2 that vincamine salts determine maximum blood levels at times significantly higher than those of vincamine hydrochloride, depositing this for a long-acting or delayed effect.

b) Apovincamine salts

For the evaluation of the delayed action of apovincamine salts, the following criteria were followed: delayed action derivatives are considered to be those compounds which after 120 'from the administration present blood levels higher than those obtained with apovincamine.

Intestinal delay compounds are considered to be salts which present after at least 120 'intestinal levels of apovincamine significantly higher than the apo-vincamine itself.

TABLE 3

Compound Time max conc.

Apovincamine 60 '

Ex. 2 120 '

Ex. 4 120 '

Ex. 6 120 '

It is evident from table 3 that the apovincamine salts determine the maximum blood levels at times significantly higher than those of the apovincamine, depositing this for a long-acting or delayed effect.

5

c) Research on blood flow

For the research relating to the cerebral vasodilator action, the tests were carried out on male hare rabbits with an average weight of kg. 3 under urethane anesthesia (1.7 g / kg i.p.). io In animals, the left common carotid artery was isolated on which blood flow was recorded by applying a 1.5 mm diameter probe connected to a Statham ST 2201 electromagnetic flow meter.

The latter was connected to an 8802 A gain amplifier (Hewlett Packard) for the graphic recording of the flow on HP polygraph mod. 7754.

Femoral artery blood pressure was also recorded by Statham pressure transducer. The drugs were administered intravenously into the isolated jugular vein isolated and cannulated with a special cannula needle. The administration of vincamine and apovincamine salts was carried out at the corresponding dose of vincamine and apovincamine of 2 mg / kg and 4 mg / kg.

For the evaluation of the vasodilator effect of the salts of 25 vincamine and apovincamine, the percentage variation of the arterial flow determined by the drug under examination was compared.

The results are reported in table 4 which shows the percentage variations of the flow found at the level of the common cara-30 tide at different times for the various compounds under examination.

The results show that the compounds made are all characterized by a vasodilator action at the level of the carotid circle from which, as is known, the arteries depart which also provide for cerebral circulation.

For some compounds, this action is much more marked than vincamine and apovincamine; for all compounds the vasodilator effect is superior in duration.

As far as blood pressure is concerned, all the compounds 40 examined have shown to perform a hypotensive action similar to that carried out by vincamine and apovincamine.

On the basis of these considerations, therefore, it can be stated that the salts object of this invention can be used both orally and parenterally in order to obtain a long-acting pharmacological effect.

It is important to underline that through the administration of these compounds it is possible to reduce the dosage of vincamine by maintaining or even improving its therapeutic action.

Ex. 8

240 '

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8

TABLE 4

Carotid blood flow changes Composed at the following times by treatment

1 '3' 5 '10' 30 '

The table shows that the delayed effect of vincamine salts and apovincamine salts is also evident from the evaluation of changes in the blood flow detected at the carotid after intravenous administration of the compounds, in fact while for vincamine and for apovincamine the maximum variations are found at 3 'and after 10' this effect has already disappeared, for salts the maximum effect occurs at 5 'and after 30' it is still evident.

Vincamina HCl

10

25

20

10

-

Ex. 1

11

22

29

19

10

Ex. 3

9

20

31

21

9

Ex. 5

12

24

27

18

11

Ex. 7

13

21

32

22

12

15

Apovincamina

10

23

18

10

-

Ex. 2

13

20

29

22

14

Ex. 4

15

22

31

16

10

Ex. 6

12

18

30

15

13

00 (À

w

10

19

28

20

15

V

Claims (11)

625240 2 1. Process for the preparation of derivatives of vincamine or apovincamine belonging to the class of glucose * 1-phosphate, glucose-6-phosphate and resorcylate, characterized in that it leads to react vincamine or respectively apovincamine, in the form of solution or suspension in a suitable solvent and when hot, with a solution of jucose - 1-phosphate, glucose-6-phosphate or respectively with 2,4-dihydroxybenzoic acid free or in the form of a salt; the mixture is kept under stirring until the reaction is completed and the desired salt is separated. 2. Process according to claim 1, characterized in that the adduct vincamine glucose-1 - disodium phosphate is obtained. 3. Process according to claim 1, characterized in that glucamine-1-phosphate is obtained, neutral salt. 4. Process according to claim 1, characterized in that glucamine-1-phosphate, acid salt is obtained. 5. Process according to claim 1, characterized in that 2,4-dihydroxy-benzoate is obtained. 6. Process according to claim 1, characterized in that the adduct apovincamine glucose - 1 disodium phosphate is obtained. 7. Process according to claim 1, characterized in that apovincamine glucose-1-phosphate, neutral salt is obtained. 8. Process according to claim 1, characterized in that apovincamine glucose-1-phosphate, acid salt is obtained. 9. Process according to claim 1, characterized in that apovincamine 2,4-dihydroxy-benzoate is obtained. 10. Process according to claim 1, characterized in that the reaction is carried out in a solvent selected from water, alcohols and chlorinated solvents and at a temperature between 20 ° C and the boiling temperature of the reaction mixture. 11. Vincamine or apovincamine derivatives obtained by the process according to claim 1. and apovincamine, having formula / N (2) i CH-, 00 C2H5 15 cerebral arteriosclerosis, due to their effective vasodilator action at the brain level and also to their ability to activate the metabolism of nerve cells. 20 However, their therapeutic action in the different routes of administration is characterized by a short duration, consequent to their rapid elimination, so that repeated administrations are necessary within 24 hours. It has now been found that some salts or associations of vincamine and apovincamine have the property of possessing similar therapeutic activity associated with a protracted effect over time, i.e. of the so-called long-acting type. More specifically, it has been found that the salts of vincamine and apovincamine which possess the aforementioned properties belong to the class comprising glucose-1-phosphate, 30 glucose-6-phosphate and resorcylate of both vincamine and apovincamine. In particular, the salts belonging to the aforementioned class are: 35 vincamine glucose-1-disodium phosphate (about 50:50 and 25:75) vincamine 2,4-dihydroxy-benzoate vincamine glucose-1-phosphate neutral salt vincamine glucose-1-phosphate salt acid apovincamine glucose-1-disodium phosphate ( 50:50 and 25:75) 4th apovincamine 2,4-dihydroxy-benzoate apovincamine glucose-1-phosphate neutral salt apovincamine glucose-1-phosphate acid salt and the corresponding derivatives with glucose-6-phosphate.