DE2250449C3 - N-disubstituted aminoethyl ester of vincamic acid and process for their preparation - Google Patents

Description

N-CH ₂ CH ₂ -X

(II)

.15

in which X is a halogen atom, in an organic solvent in the presence an A'ikalicar-4c which is insoluble in the reaction medium bonats heated in an inert atmosphere or b) a compound of the general formula

N-CH ₂ -CH ₂ -X · HCl (111)

45

with an alkali salt of vincamic acid in the presence of an acid acceptor that is insoluble in the reaction medium and of dry acid Potassium acetate in a solvent at its reflux temperature for reaction brings, filtered off from the potassium chloride formed, and the resulting product by feeding from dry gaseous hydrogen chloride or from concentrated hydrochloric acid precipitates as dihydrochloride or

c) in the presence of an alkali metal alcohol dissolved in an aromatic hydrocarbon get an amino alcohol of the general formula R.

N-CH ₂ -CH ₂ -OH (IV) fts

inert atmosphere and protected from light with heating for about 7 hours and the resulting ester is isolated as a dihydrochloride.

The invention relates to N-disubstituted aminoethyl esters of vincamic acid of the general formula

N-CH, -CH _{5 -OOC}

in which the two R are methyl radicals or together with the nitrogen atom to which they are attached are, form a piperidino, morphoiino or pyrrolidino group and their dihydrochlorides and processes for the preparation of these esters.

These esters are useful for therapeutic purposes. Comparative experiments between the compounds according to the invention and vincamine led to the following results: vincamic acid dimethylaminoethyl ester is designated with A _1, vincamic acid morpholinoethyl ester with B, vincamic acid piperidinoethyl ester with C and vincamic acid pyrrolidinoethyl ester with D.

1. Acute toxicity tests were carried out on mice to determine the lethal dose LD ₅₀ by the method of Kerber and Behrens. The results were as follows:

Table I.

Dosage in mg / kg p. 0. (oral) i.v. LD50 HCI medium *) LD ₅₀ 850 Vincamine 42 > 1000 A. 117 > 1000 B. 98 940 C. 82 870 D. 55.5

reacts with vincamine and the reaction in *) says. that the vincamine, which is water-soluble, is dissolved in an aqueous hydrochloric acid solution to form an injectable solution.

2. Furthermore, experiments on the hemodynamic effects on were selected at random male and female dogs weighing 15 to 20 kg. The dogs were through Injection of about 1% chioralose solution at a dosage of about 100 mg / kg into the saphenous veins anesthetized. The dogs were anesthetized by slowly throughout the duration of the experiments Sodium 5-ethyl-5- (l-methylbutyl) barbiturate in one Dosage of about 0.1 mg / kg / min / 0.005 ml was infused into the saphenous vein. The dogs were Artificially ventilated and received injections of the substances to be tested in doses of about 1/10 LD50 with the exception of vincamine, the dose of which was slightly higher.

Vio LDsc was chosen to increase the intensity the pharmacological effects of different substances under identical toxicity conditions for Compare all products except for

Table II

the vincamine, which was dosed a little higher in order to get a slightly better value for vincamine.

The results are given in Table Ii below.

A.
11.7 mg / kg B.
9.8 mg / kg C.
8.2 mg / kg D.
5.5 mg / kg Vincamine
73 mg / kg Contraction force ^ 23% Ml% ^Ν 15% ^ 10% Thickness of the femoral artery Diast ^ l 8%
Syst s 3% Diast ^ 9%
Syst ^N 12% Diast ^s U ° / o
Syst ^N 8% Diast ^N 5%
Syst ^N 12% ^N 20%
^X HO / o Internal maxillary veins
pressure / 129% _/ 141% / 167% / 135% / 117% Heart rate ^N ll% ^ 15% M 5% ^N 6% s 7% Peripheral vascular resistance ^ 62% ^S 51% ^% 60% ^N 40% "· 370/0 Vertebral arteries
flow * 142% / 167% / 181% / 138% / 127% Femoral artery flow , .33% / 35% /> 57% ^ 34% ^ • 22%

3. Experiments were carried out on human blood to determine the effects of the compounds on platelet aggregation using the method of Prost et al (Jouen Coagulation, 5,145 [1971]) of an aggregometer according to Mustard.

Table III

C% o (a) PRP *)

C% o final value

ADP

Inhibition

C% o final value Adrenaline inhibition

C% o
Final value

Collagen inhibition

Papaverine

Vincamine

250 μΜ
125 μΜ
25 μΜ 3.1
3.1
3.1 μΜ
μΜ
μΜ + + ±
+ ±
0 3.1 μΜ
1.1 μΜ
3.1 μΜ 0 250 μΜ
125 μΜ
25 μΜ Ui Ui Ui μΜ
μΜ
μΜ + + + ± 6.25 μΜ
6.25 μΜ
6.25 μΜ ±
0 250 μΜ
125 μΜ
25 μΜ 3.1
3.1
3.1 μΜ
μΜ
μΜ + + + ±
± 6.25 μΜ
6.25 μΜ
6.25 μΜ 0 250 μΜ
125 μΜ
25 μΜ rf rf rf μΜ
μΜ
μΜ + ±
0 ± 6.25 μΜ
6.25 μΜ
6.25 μΜ 0 250 μΜ
125 μΜ
25 μΜ Ui Ui Ui μΜ
μΜ
μΜ + + 6.25 μΜ
6.25 μΜ
6.25 μΜ ±
0

250 μΜ

3.1 μΜ

6.25 μΜ

(a) C 96ο means concentration per liter.

250, 125, 25 μΜ indicates the concentrations of the test substances.

The other digits refer to the concentration values of the aggregating agent.

0 means no effect on the aggregation,

+ means little impact on aggregation,

+ + means medium inhibition of aggregation,

+ + + means complete inhibition of aggregation,

± means uncertain intensity of the inhibiting effect.

*) Platelet-rich plasma.

Ln Ui Ui
OOO
TTT
222 0
0 50 μΜ
50 μΜ
50 μΜ 0 50 μΜ
50 μΜ
50 μΜ 0 50 μΜ
50 μΜ
50 μΜ 0 50 μΜ
50 μΜ
50 μΜ 0 5OuM 0

4. Further experiments were carried out to determine the hypolipemic effect of the compounds. Male rats of an original body weight of about 250 g, given food and drink free accessible were divided into four groups of 8 rats each. The rats received one each daily injection of the compounds to be tested into the bones of the animals at a dose of 65 mg / kg

('S within 8 days. A group of 16 rats served as a control group. The rats were sacrificed under ethereal anesthesia 15 hours after the last injection. The thorax was then cut open and blood was drawn intracardiacally. The blood was tested for total lipids ( Sulpho-Phospho-Vanilin) according to the method of Tollner and was made according to the method of Van

Hand and Z i 1 ν e r s with examined for triglycerides. The results of these experiments are given in Tables IV and V below.

Table IV
Triglycerides:

Control dose

Differences from the mean

Qu; .drat d. differences

1.44

1.44 1.50 1.36 1.50 1.44 1.72 1.50 1.44 1.44 1.5 1.58 1.30 1.30 1.44 1.44

Total = 23.34 mean

0.02 0.02 0.04 0.10 0.04 0.02 0.28 0.04 0.02 0.02 0.04 0.12 0.16 0.16 0.02 0.02

= 1.46 6 = R ^

0.0004 0.0004 0.0016 0.0100 0.0016 0.0004 0.0784 0.0016 0.0004 0.0004 0.0016 0.0144 0.0256 0.0256 0.0004 00004 -CU632

= 10.011 = ± 0.105

Permissible limit = 1.46 ± 0.105

A B C D

Table V

Total lipids:

Mean = , 41 N.S. Mean = , 11 S. Mean = , 18 S. Mean = 1.02 S. Mean = 1.02 S.

Control dose

4.35 4.50 4.35 4.35 4.30 4.00 5.00 4.30 3.25 3.55 3, (K) 4.20 4.50

Differences from the mean

0.23 0.38 0.23 0.23 0.18 0.12 0.88 0.18 0.87 0.57 1.12 0.08 0.38

Square d. differences

0.053 0.144 0.053 0.053 0.032 0.014 0.774 0.032 0.757 0.325 1.254 0.006 0.144 Control dose

differences jicgcnabcr mean value

3.70
4.30
4.20

Total score = 65.85
Mean = 4.12 6 =

0.42
0.18
0.08

• Juadrai d differences

0.176 0.032 0.006 3.855

• 3 OCC

'- ^ = 10.257 = ± 0.507

Permissible limit value [4.12 ± 0.5 071

substance

Vincamine Mean = 4.06 N. S. A. Mean value = 3.42 S. B. Mean = 3.35 S. C. Mean = 3.15 S. D. Mean value = 3.26 S.

Annotation:

N.S. means dall the effect of lowering the lipid or Triglyceride content with respect to the control group is not significant.

S means that this effect is statistically significant.

5. Experiments were carried out to determine the antidepanocidal activity of the compounds. in the In case of drepanocytosis, sickling appears to be due to a temporary lack of oxygen in the red Due to blood cells. Accordingly, any substance that sickles in vitro in the absence of oxygen delayed or inhibited theoretically active against the clinically detectable Observation of drepanozitären effects, since these are essentially due to intravascular sickling phenomena are due.

A modified, accelerated embodiment of the conventional sickle test was in attendance of a reducing agent, here sodium metabisulphite. The blood used for the experiments came from it of SS homozygotes. The red blood cells and the solutions of the products to be tested were taken brought into contact with one another in the absence of air and incubated at 37 ° C for 30 minutes calmly.

Observation was then made with a microscope. The 5+ means that all cells are sickling have (no effect), 1+ means that a small number, if any, of cells with Sickling were observed.

Products Concentrations of the substances under investigation (, 0 (aqueous solution)

ΙΟ ^"3 mg / ml of 10- ² mg / ml 10"'mg / ml

Vincamine 5 + 3 + 1 + A. 5 + 2 + 1 + B. 5 + 2 + 1 + C. 4 + 1 + 1 + D. 4 + + ■ 1 +

Conclusions

The new vincamine esters are remarkably less toxic than vincamine.

They have a much better hemodynamic effect than vincamine on the cerebral blood flow, expressed as a percentage of the increase in internal maxillary venous pressure and in particular vertebral arterial flow. This increase is 10 to 50% higher than for vincamine. Besides that the new vincamine esters delay the sickle formation quite decisively and much more effectively than vincamine of red blood cells in SS homozygote subjects, and this up to a concentration of 10-mg / ml.

The compounds of the invention also have useful properties similar to those of vincamine are not found because they have hypolipemic and platelet aggregating properties, as by tests on hypolipemic activity and platelet anti-aggregation properties has been proven.

The compounds of the invention can be prepared by adding vincamic acid in Zwitterion form with a substituted haloaminoethane of the general formula

N-CH ₇ -CH ₂ -X

(H)

in which X is a halogen atom, in an organic solvent in the presence of one in the reaction medium insoluble alkali carbonate heated in an inert atmosphere.

Anhydrous alcohol, in particular isopropanol, can be used as the organic solvent. Each other organic solvents which do not dissolve the alkali carbonates can also be used. Potassium carbonate is preferably used as the alkali carbonate. It is used in the course of the reaction to bind released hydrohalic acid. This will bring the balance in the way you want Senses shifted and the yield increased.

The vincamic acid required as a starting material can be saponified either from vincamine or from Prepare epi-16 vincamine. The vincamic acid is used at the pH value at which its isoelectric point lies, in the form of zwitterions through precipitation directly from the Separated saponification mixture.

Due to the insolubility of the zwitterion in the saponification mixture, losses are avoided and the Yield is increased. In addition, the acid obtained has a high degree of purity, since the mineral and organic salts remain in solution.

To prepare the compounds according to the invention, one can also use a compound of the general formula

N-CH ₂ -CH ₂ -X · HCl (111)

and dry potassium acetate in a solvent such as isopropanol at its reflux temperature Bring reaction, filter off the potassium chloride formed and the resulting product through Feeding in dry gaseous hydrogen chloride or concentrated hydrochloric acid as dihydrochloride fail.

Finally, the compounds according to the invention are also obtained by reacting in the presence of an alkali metal alcoholate dissolved in an aromatic hydrocarbon, preferably an amino alcoholate or sodium methylate, an amino alcohol of the general formula

N-CH, -CH, -CH

(IV)

with an alkali salt of vincamic acid in the presence of an acid acceptor which is insoluble in the reaction medium Reacts with vincamine and the reaction in an inert atmosphere and protected from light with heating carried out for about 7 hours and the resulting ester isolated as dihydrochloride

Any methanol formed during the reaction can be eliminated using molecular sieves. In this way, the equilibrium and the yield are shifted in the desired direction increased. The molecular sieve is not required in all cases and can also be used by other means Trapping of methanol to be replaced.

The product is separated from the organic phase by washing with water to remove the unreacted Eliminate alcohol. The organic phase is then dried over sodium sulfate and in vacuo Evaporated to dryness. The residue obtained is dissolved in an organic solvent and mixed with dry, gaseous hydrogen chloride or treated with concentrated hydrochloric acid to do this to obtain the desired dihydrochloride.

The invention is explained in more detail by the following exemplary embodiments

example 1

Vincamic acid dimethylaminoethyl ester dihydrochloride

3.4 g of vincamic acid, 100 ml of anhydrous isopropanol and 1.2 g of anhydrous sodium carbonate are with 1.1 g of dimethylaminochloroethane heated under reflux in an inert atmosphere. The zwitterion follows and after in solution. At the end of the reaction, the precipitate is filtered off and washed with something dry Washed isopropanol. The filtrate is mixed with gaseous hydrogen chloride to a pH of about 2 acidified A white precipitate forms in a mixture of isopropanol and ethanol is recrystallized; Yield 3.7 g (77% of theory).

Vincamic acid dimethylaminoethyl ester dihydrochloride:
F. 201 ° -202 ⁰ C;
(<x) _D : + 9- (C = I) (H ₂ O);
UV: Max. At 228 and 280 πιμ;
ft.s IR: carbonyl ester at 1745 cm- ';
Analysis: C ₂₄ H ₃₅ N ₃ O ₃ Cl ₂

Calculated: C 59.50, H7E N 8.67%;
found: C 59.48, H 7.19, N 8.69%.

Vincamic acid dimethylaminoethyl ester:
F. 103 ° -104 ⁰ C;
(<x) _D : 0 ± 2 (C = I) (MeOH);
UV: Max. At 228 and 280 πιμ;
IR: carbonyl ester at 1745 cm - ';
Analysis: C ₂₄ H ₃₃ N ₃ O ₃

Calculated: C 70.24, H 7.85, N 10.02%;

Found: C 70.14, H 7.06, N 10.31%.

Example 2

Vincamic acid dimethylaminoethyl ester dihydrochloride

3.79 g of potassium vincaminate, 0.98 g of dry potassium acetate and 1.7 g of dry potassium carbonate are suspended in 150 ml of isopropanol. The mixture is placed in an ice bath and cooled to a temperature between 5 ° C and 10 ⁰ C. Then 1.58 g of dimethylaminochloroethane hydrochloride are added in small amounts. As soon as everything has been added, the suspension is refluxed for one hour and then cooled. The precipitate is filtered off and washed with a little isopropanol. The filtrate is acidified with gaseous hydrogen chloride to a pH of about 2. A white precipitate forms, which is recrystallized from a mixture of isopropanol and ethanol. The same physical constants as in Example 1 are obtained; Yield 3.9 g (81% of theory).

Example 3

Vincamic acid dimethylaminoethyl ester dihydrochloride

A solution of 8.9 g of dimethylaminoethanol in 150 ml of dry benzene is 0.023 g of sodium added. The mixture obtained in this way is mixed with 3.5 g of vincamine and then in a nitrogen atmosphere and refluxed for 7 hours, protected from light. Then the reaction mixture cooled and washed with water. The benzene phase is then over anhydrous Sodium sulfate dried and evaporated to dryness in vacuo. The residue is dissolved in isopropyl alcohol dissolved and acidified with gaseous hydrogen chloride; Yield 4.1 g (85% of theory).

Mp 201 ° -202 ° C;

(<x) d: + 9 ° (C = I) (H ₂ O);

U.V .: Max. At 228 and 280 Γημ;

I.R .: carbonyl ester at 1745 cm - ';

Analysis: C ₂₄ H ₃₅ N ₃ O ₃ CI ₂

Calculated: C 59.50, H 7.23, N 8.67%;

found: C 59.48, H 7.19, N 8.69%.

Example 4

Vincamic acid dimethylaminoethyl ester dihydrochloride

The reaction is carried out in a Soxhlet. 3.9 g of vincamine hydrochloride, 8.9 g of dimethylaminoethanol, 0.54 g of sodium methylate and 150 ml of dry benzene were introduced. In the 10 g molecular sieve of type 4 A are used in the filter paper cartridge of the Soxhlet. The mixture is 7 Refluxed for hours under a stream of nitrogen. The transesterification takes place completely. The The mixture is then cooled and washed with water. The benzene phase is then over anhydrous Sodium sulfate dried and evaporated to dryness in vacuo. The residue is dissolved in isopropyl alcohol dissolved and acidified with gaseous hydrogen chloride.

The same physical constants as in Example 3 are obtained; Yield 4 g (83% of Theory).

The compounds listed below were each made after one of those described above Process made:

1) Vincamic acid morpholinoethyl ester dihydrochloride
M.p. 205-206 ° C;

(x) d: + 7 ° (C = I) (H ₂ O);
jo UV: max. at 222 and 272 Γημ;

IR: carbonyl ester at 1745 cm - ';
Analysis: C ₂₆ H ₃₇ N ₃ O ₄ CI ₂

Calculated: C 59.09, H 7.01, N 7.95%;
found: C 59.12, H 7.04, N 7.87%.
Yield 83% of theory.

2) vincamic acid pyrrolidinoethyl ester dihydrochloride

195-196 ° C;
((K) ₀ : + 18 ° (C = I) (H ₂ O);
₄ n UV: max. At 223 and 272 πιμ;

LR .: carbonyl ester at 1745 cm - ';
Analysis: C ₂₆ Hi ₇ NjOjCl ₂

Calculated: C 61.17, H 7.25, N 8.23%;
found: C 61.09, H 7.29, N 8.19%.
Yield 73% of theory.

3) Vincamic acid piperidinoethyl ester dihydrochloride

Mp 194-195 ° C;
(<x) _D : + 5 ° (C = I) (H ₂ O);
UV: Max. At 222 and 272 πιμ;

LR .: carbonyl ester at 1745 cm - ';
Analysis: C ₂₇ H ₃₉ N ₃ O ₃ Cl ₂

Calculated: C 61.83, H 7.44, N 8.01%;
found: C 61.78, H 7.50, N 8.04%.
Yield 85% of theory.

Claims (6)

Patent claims: 1. N-disubstituted aminoethyl ester of vincamic acid of the general formula HO N -CH, -CH, -OOC in which the two R are methyl radicals or together with the nitrogen atom to which they are attached are bonded, form a piperidino, morphoiino or pyrrolidino group, and their dihydrochlorides. 2. Vincamic acid morpholinoethyl ester dihydrochloride. 3. Vincamic acid pyrrolidinoethyl ester dihydrochloride. 4. Vincamic acid piperidinoethyl ester dihydrochloride. 5. Vincamic acid dimethylaminoethyl ester dihydrochloride. 6. Process for the preparation of the compounds according to claim 1, characterized in that one a) either vincamic acid in zwitterionic form with a substituted halo-aminoethane the general formula