IT8322537A1 - 3-ALPHA TOLUIL ETHERS SUBSTITUTED BY ASCORBIC ACID, PROCESS FOR THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS INCLUDING THEM AS ACTIVE SUBSTANCE - Google Patents

Description

Patent Application for Industrial Invention entitled: "3-alpha toluil ethers substituted by ascorbic acid, process for their preparation and pharmaceutical compositions that include them as an active principle"

Summary

Has a new series of 3- ethers been prepared? toluil substituted by the formula ascorbic acid

by reaction of the corresponding benzyl bromides and ascorbic acid.

Do the new compounds have activity? antilipidoperoxy -dante and therefore are useful in the prevention and treatment of aging processes, of atherosclerosis; liver poisoning, fibrinogenesis, carcinogenesis and in general all those diseases connected with lipid peroxidation.

Description

The present invention relates to a new series of 3 -? (Toluil substituted ethers of ascorbic acid, the process for their preparation and their use in the pharmaceutical field.

The invention also includes pharmaceutical compositions which contain them as active ingredients. Are the new compounds 3- ethers? toluil substituted by ascorbic acid responding to the general formula:

in which the same or different from each other, they represent a hydrogen atom, a halogen, a linear or branched alkyl group, phenyl, benzyl, linear or branched alkoxy, benzyloxy, nitrogroup, trifluoromethyl group, provided? they are never all the same hydrogen. The new compounds object of the present invention can be prepared by reacting the acid

ascorbic with the corresponding benzyl halides

substituted by the general formula:

in which they are defined as before and X

Br, C1, I, according to the equation:

Mixtures of

water and solvents miscible therein such as for example

acetone, methanol, ethanol, propanol, dimethylformamide, tetrahydrofuran, dimethyl sulfoxide.

According to a preferred embodiment, the ascorbic acid is dissolved in water and the buffered solution

at pH between 3 and 7, preferably 5, for example with

molarity phosphate buffer? between 0, 1 and 1 M;

is then added the desired halide in quantity? between 0, 5: 1 and 1: 1 molar, preferably 0.75: 1

molar than ascorbic acid,

an organic solvent miscible with water, preferably acetone, in a concentration comprised between 1 and 20% and is heated to a temperature comprised between 10? and the 70? C. The reaction time obviously depends on the temperature used: with a temperature of 20 ° C, times of 48 hours are generally required, while at 70 ° C the time drops to 2 hours. At the end of the reaction the organic solvent is evaporated under vacuum.

Optionally, distilled water is added and the unreacted halide is extracted with a solvent selected from the group consisting of toluene, hexane, cyclohexane, diethyl ether, tert-butyl methyl ether. The reaction product is extracted from the residual solution, preferably with ethyl acetate. The solvent is then evaporated under vacuum, the residue is taken up with distilled water and it is dissolved while hot.

Decolorizing charcoal is added, filtered while hot and the product is allowed to crystallize.

With many of the halides mentioned above, in addition to the alkylation of oxygen in 3, an alkylation at the carbon atom 2 is also observed.

The resulting product at the end of the treatment described above is in this case a mixture of 3-0-alkylated and 2-C-alkylated products.

In this case, the purification of the raw product is carried out in the following way. Is the crude product dissolved in methanol in a concentration varying between 5% and 20% depending on its solubility? and 5% with respect to the methanol used 28% concentrated ammonia is added. It is left to react at room temperature for 1 hour. This treatment causes the degradation of the substituted compound at carbon 2. The methanol and ammonia are evaporated under vacuum, the oily residue is taken up with water, the oily residue is brought to pH = 5 and the oily residue is dissolved when hot. Decolorizing charcoal is added, filtered while hot and the product is allowed to crystallize. The preferred halides for carrying out the new process are bromides. Many of the bromides mentioned above are commercially available. Bromides not commercially available can be prepared from the corresponding commercially available benzyl alcohols.

In this case can? the following process be adopted. The desired benzyl alcohol is dissolved in dimethylformamide in concentrations ranging from 5% to 20% and, under appropriate cooling, a quantity is added. equimolecular of PBr3. It is left to react for 30 'and then it is diluted with water.

The bromide which is used as such for the preparation of the new compounds of formula I precipitates or separates as oil.

Some examples are reported for illustrative purposes only, but in no case limiting the present invention.

Example 1

Preparation of 3-0- (4 bromobenzyl) -L-ascorbic acid (MD 158)

425 g of L-ascorbic acid are dissolved in 41 of distilled water.

500 g of are added and the resulting solution is brought to pH = 4.75 with 40% NaOH.

Separately, 400 g of 4-bromobenzyl bromide are dissolved in 4 1 of acetone and added to the previous aqueous solution.

The mixture is heated under stirring and is left to react for 3 hours.

The reaction mixture is cooled. The acetone is evaporated under vacuum.

It is diluted with distilled water up to a volume of 8 1.

Any unreacted benzyl bromide and the corresponding benzyl alcohol formed by hydrolysis of the former are extracted twice, with 11 of benzene each time.

The reaction product is extracted 3 times, with 1 1 of ethyl acetate each time.

It is brought to dryness by completely evaporating under vacuum l? ethyl acetate.

The oily residue is taken up with distillate, heated until completely dissolved, 50 g of activated carbon are added and filtered while hot. The product is allowed to crystallize.

It is filtered, washed with and dried under vacuum. 300 g of product are obtained.

The raw product so? obtained ? an approximately 50% mixture of 3-0-alkylated and 2-C-alkylated products.

The crude product is dissolved in 21 of methanol containing 5% of concentrated aqueous 28% (100 ml).

Can it react at room temperature for 50? and then the methanolammonia mixture is evaporated under vacuum.

The oily residue is taken up with 21 di and a few drops of up to pH = 5.

It is heated until complete dissolution, 30 g of activated carbon are added, filtered while hot and the product is left to crystallize at 3 ° C.

120 g of final product are obtained.

The IR spectrum of the product cos? obtained shows the two intense bands at 1,760 and 1,685 characteristic of ascorbic acid derivatives, while

? the 1,790 band characteristic of the 2-C-alkylated product completely disappeared.

The product at the U.V. shows a maximum absorption at 240 nm with? = 13,800.

The elementary analysis d? the following result:

Examples 2-10

Operating as in example 1, but using instead

4-bromobenzyl bromide respectively 4-fluoro benzyl bromide, 2-bromo benzyl bromide, 3-bromo benzyl bromide, 2-nitrobenzyl bromide, 3-nitro benzyl bromide, 4-nitro benzyl bromide, 3-methyl benzyl bromide, 4- methyl benzyl bromide, 2-chloro - 4-nitro benzyl bromide, the respective derivatives are obtained

3-0-alkyl substitutes of ascorbic acid whose characteristics are reported in the following

table 4

TABLE 4

Example 11

Preparation of 3-0- (4 chlorobenzyl) -L-ascorbic acid (MD 155)

284 g of 4-chlorobenzyl alcohol are dissolved in 11 of N, N dimethylformamide in an ice bath and under stirring 100 ml of

It is left to react for 30 minutes, and then the reaction mixture is diluted with 41 di

The 4-chloro benzyl bromide precipitates which is collected by filtration, washed with and redissolved with 4 1 of acetone.

Apart from 425 g of L-acorbic acid are dissolved in 4 1 of distilled water.

500 g of are added and the resulting solution is brought to pH = 4.75 with 40% NaOH.

This aqueous solution is added to the previous acetone solution and heated under reflux under stirring for 3 hours.

We proceed from this point onwards, exactly as described in example 1.

105 g of product are obtained having the following characteristics:

I.R. = two intense bands at 1,760 and 1,685

characteristics of ascorbic acid derivatives, while? the band at 1,790 cm 1 characteristic of the 2-alkylated product is completely absent;

U .V. ? maximum absorption at 244 nm with = 13 - 020. Elemental analysis:

theoretical

found :

Example 12

One operates as in example 11 using as starting products instead of 4-C1 benzyl alcohol, respectively, 2-fluoro benzyl alcohol, 3-fluoro benzyl alcohol, 2-chloro benzyl alcohol, 3-chloro benzyl alcohol, 2-iodobenzyl alcohol, 3-iodobenzyl alcohol, 3-trifluoromethyl benzyl alcohol, 4-tert-butyl benzyl alcohol,

2-phenyl benzyl alcohol, 4-phenyl benzyl alcohol, 4-methoxy benzyl alcohol.

Do you get quantities? varying between 80 and 130 g. of 3-0-alkylated products, with I.R. and U.V. similar to those of the products described in the previous examples.

The melting points of all compounds prepared according to the process described are shown in the following table 1.

TABLE 1

In addition, all compounds show the I.R. the bands at 1,760 and 1,685

As initially said, the compounds of the present invention were found to be endowed with activity? antilipidoperoxidant e.

This activity? ? has been evidenced by "in vitro" (A) and "in vivo" (3) tests.

A) Activities "in vitro" antilipid peroxidant

It was evaluated on rat liver and brain homogenates.

Liver: a quantity? of supernatant (9 mg protein) obtained by centrifugation at 10,000 g x 151 of rat liver homogenate in 1.15% KC1 was incubated for 1 hour at 37 ° C in a NADPH system generating 0.1 M Tris-HCl pH 7 buffer , 4, as described by Cignoli et al. in Exp. Mol. Pathol. 14: 43-56, 1971.

Lipid peroxidation, induced by 4? L of

in the incubation mixture (final volume 3 ml)? was evaluated as malondialdehyde production by means of the colorimetric reaction with thiobarbituric acid (Cignoli et al.).

The products tested at a concentration of 10071M (final conc.) Were dissolved in an aqueous solution of 10% alcohol.

Was an equal amount added to the control samples? of alcohol.

The results obtained are shown in Table 2, expressed as a percentage inhibition of the development of malondialdehyde with respect to control samples to which only carbon tetrachloride was added. The reported values represent the mean of 2 determinations.

Brain: a quantity? of brain homogenate in KC1 150 mM (l g / 20ml) corresponding to about 0, 5 mg protein was incubated 1 hour at 37 ° C in 0.2 M Trisacetate buffer pH 7.0 (final volume 0.5 ml) according to the method described by Bishayee et al. in J. Neurochem. 18: 909-920, 1971.

The lipid peroxidation induced by adding to the ac system. 0.3 mM ascorbic acid was evaluated as malondialdehyde development (MDA).

The products at a concentration of 100? M (final conc.) Were dissolved in a 10% alcohol solution. Was the same amount added to control samples? of alcohol.

The results obtained are shown in table 2 and expressed as a percentage inhibition of the development of MDA in the samples compared to the controls to which only ac was added. ascorbic (0.3 mM).

The reported values represent the mean of 2 determinations.

B) Activities "in vivo" antilipid peroxidant

It was evaluated as the production of pentane exhaled by rats after treatment with CC1 at a dose of 90? L / 100 gr i.p. in 30% mineral oil.

The products were administered at a dose of 200 mg / kg / os in 2% gum arabic, simultaneously with the administration of CCl4, 1 hour before the determination.

The pentane exhaled by the animal, placed in a suitable glass container, was evaluated by gas chromatography according to the method of Hartmut et al. (Toxicol. Appi. Pharmacol. 56: 337-344j 1980).

The quantity of pentane exhaled by the animal and measured as the area of the peak obtained, was calculated by referring to the area of the peak obtained after injection of a quantity? note of pure pentane gas. The results reported in table 3 and obtained 3 hours after the administration of CCl4 are expressed as a percentage of inhibition of the production of pentane exhaled by animals treated with the products under examination, compared to control animals that received only 2% gum arabic. The reported values are the average of determinations carried out on 5 rats for each product.

As shown in tables 2 and 3, the compounds of the present invention inhibit, in many cases in percentages higher than 50%, both in vitro at the hepatic and cerebral level, and "in vivo", the lipid peroxidation processes.

These processes are implicated in the onset of physiological processes such as aging (J. Gerontol. 23: 470-482, 1968; Life Sci. 27: 731-738, 198?), Or in pathological processes such as atherosclerosis (Am . J. Pathol. 22: 135-144, 1952; J. Pathol. Bacteriol. 72: 267-269, 1956; in: Metabolism of Lipids as Related to Atherosclerosis, edited by F.A. Kummerow, Springfield: Thomas 1965, p. 18 and page 48), cellular degradation processes in the phage and brain (Pharmacol. Rev. 19: 145, 1967; Federation Proc. 26: 1436, 1967; Physiol. Rev. 48: 331, 1968), induced carcinogenesis by chemical agents (in: Free Radicale Lipid Peroxidation and Cancer, edited by D.C.H. MacBrien and T.F. Slater). In the particular case of lipid peroxidation induced experimentally by an acute dose of alcohol in the rat (Pharmacology 22: 343-348, 198l) the compounds of the present invention have proved capable of preventing the drop in hepatic glutathione (GSH) levels.

Active products such as antilipidoperoxidants are used in human therapy in the treatment and prevention of all those processes, such as aging, atherosclerosis, liver intoxication, fibrogenesis, carcinogenesis, in which? there is known to be an increased production of lipid peroxides.

TABLE 2

TABLE 3

The invention also relates to pharmaceutical forms containing the products described above. The pharmaceutical compositions must contain as active principle at least one compound selected from those of Table 1 and pharmaceutically acceptable solid or liquid excipients and auxiliary agents.

The product can? be presented in different pharmaceutical forms, such as tablets, pills, capsules, tablets-delay, suspensions, suspensions-delay, syrups, syrups-delay, creams, lotions, suppositories, injectable forms.

Some examples of pharmaceutical formulations are shown below.

Example 13

Preparation of MD 152 tablets

1 tablet of 50 mg contains:

MD 152 50 mg

Lactose 75 mg

Starch 30 mg

PVP 6 mg

Magnesium stearate 4 mg

500 g of MD 152, 750 g of lactose, 300 g of starch and 60 g of PVP are granulated together.

Magnesium stearate is added.

It is compressed and about 10,000 tablets are obtained, each containing 50 mg of MD 152.

Example 14

Preparation of of MD 182

1 tablet of 50 mg contains:

MD l82 50 mg

Lactose 75 mg

Starch 30 mg

PVP 6 mg

Magnesium stearate 4 mg

For the preparation proceed as in example 13. Example 15

Preparation of MD 155 tablets

1 tablet of 50 mg contains:

MD 155 50 mg

Lactose 75 mg

Starch 30 mg

PVP 6 mg

Magnesium stearate 4 mg

Is the preparation carried out as in example 13? R i v e n d i c a z i o n i

1. 3-alpha toluil-substituted ethers of the ascorbic acid of formula

in which the same or different from each other represent hydrogen, halogen, alkyl

linear or branched, phenyl, benzyl, linear or branched alkoxy, benzyloxy, nitro, trifluoromethyl, provided? at least one of them is other than hydrogen.

2. Process for the preparation of 3-alpha toluil-substituted ethers of scorbic acid of formula

in which the same or different from each other represent hydrogen, halogen, alkyl

linear or branched, phenyl, benzyl, linear or branched alkoxy, benzyloxy, nitro, trifluoromethyl, provided? at least one of them is different from hydrogen, characterized in that a benzyl halide of the formula is reacted

in which they are defined as above and X = Br, Cl, I, with ascorbic acid, in an aqueous-organic medium, at temperatures between 10? and 70? C.

Process according to claim 2, wherein the organic solvent? selected from the group consisting of acetone, methanol, ethanol, propanol, dimethylformamide, tetrahydrofuran, dimethyl sulfoxide. 4- Therapeutic compositions with activity? antilipid peroxide comprising as active principle at least one compound according to claim 1, in admixture with therapeutically acceptable solvents and / or diluents.