DE1493963C - Substituted Flavandes and Processes for Their Production - Google Patents

Description

R _{1 is} a hydroxyl, methoxy or ethoxy group or the radical -OCH ₂ CONH ₂ or - OCH ₂ COOC ₂ H ₅ ,

R _{2 is} an alkoxy group having 1 to 5 carbon atoms and

R _{3 represents} an oxygen atom or at the same time a hydrogen atom and a hydroxyl group.

2. Process for the preparation of substituted flavan derivatives of the general formula I.

25th

in the

R ₁ denotes a hydroxyl, methoxy or ethoxy group or the radical -OCH ₂ CONH ₂ or - OCH ₂ COOC ₂ H ₅ ',

R _{2 is} an alkoxy group having 1 to 5 carbon atoms and

R _{3 represent} an oxygen atom or at the same time a hydrogen atom and a hydroxyl group,

characterized in that a ketone optionally generated in situ of the general Formula II

II

OH

CO-C (CHj) = CH

in which R ₁ and R _{2 have} the meaning given above and where phenolic hydroxyl groups can also be present in protected form, cyclized in a manner known per se in the presence of a basic or acidic catalyst and, if the product obtained contains a protected hydroxyl group, this is conventionally Way by treatment with hydrolyzing and / or reducing agents sets free or that a flavone derivative of the general formula III

III

in which R ₁ and R _{2 have} the meaning given above

possess, treated in a manner known per se with reducing agents and that optionally in a compound of the general formula I obtained in which R _{1 represents} a free hydroxyl group, this is converted into a methoxy or ethoxy group or the in a conventional manner by treatment with an etherifying agent rest

- OCH ₂ CONH ₂ or - OCH ₂ COOC ₂ H ₅

transferred or the one in the 4 position The keto group is reduced to a hydroxyl group in the usual way.

3. Medicament containing a compound of the general formula I given in claim 1 in addition to the usual inert carriers and additives.

The invention relates to substituted flavan derivatives of the general formula I.

in the

R _{1 is} a hydroxyl, methoxy or ethoxy group or the radical -OCH ₂ CONH ₂ or - OCH ₂ COOC ₂ H ₅ ,

R _{2 is} an alkoxy group having 1 to 5 carbon atoms and

R _{3 represents} an oxygen atom or at the same time a hydrogen atom and a hydroxyl group.

These flavan derivatives have very valuable pharmacological ones, especially those that lower cholesterol levels Properties.

The cholesterol-lowering effect was determined in rats according to that of C ο u η s e 11 et al in J. med. pharm. Chem., Vol. 5, pp. 720 and 1224 ff (1962), described method determined. So resulted in a Oral administration of 25 mg / kg of 3-methyl-6-hydroxy-4'-isoamyloxy-fiavanone lowering cholesterol level in the serum of 29%. In contrast, the known compound shows 2-p-chlorophenoxy-2-me ethyl propionate (cf. British patent specification 860 303) in the higher dosage of 50 mg kg, all other things being equal, the cholesterol level was reduced by only 8%.

Compared to other known cholesterol levels! lower like 20,25-diaza-cholesterol, 22,25-diaza-chc lesterine, 25 - aza - cholesterol, 3/5 - diethylamino acid oxy - 5 - androsten - 17 - one, 1 - [p - (2 - diethylamine ethoxy) - phenyl] -1 .- (ρ - tolyl) - 2 - (ρ - chlorophenyl ethanol and trans -1,4-bis- (2-chloro-benzylamine methyl) - cyclohexane, the compounds according to the invention are distinguished by the fact that according to him Administration no unphysiological accumulation of desmosterin or 7-dehydro-cholesterol in German Serum sterols occurs and the total sterol content in the serum decreases.

The substituted flavan derivatives of the general formula I given above are thereby hc

provided that a ketone of the general formula II, which may be generated in situ

OH

II

CO- C (CH ₃ ) = CH- <

in which R ₁ and R _{2 have} the meaning given above and where phenolic hydroxyl groups can also be present in split form, cyclized in a manner known per se in the presence of a basic or acidic catalyst and, if the product obtained contains a protected hydroxyl group, these are conventionally Way, by treatment with hydrolyzing and / or reducing agents, or that a flavone derivative of the general formula III '

III

in which R ₁ and R _{2 have} the meaning given above, treated in a manner known per se with reducing agents and that optionally in a compound of the general formula I obtained in which R _{1 represents} a free hydroxyl group, this is treated in the customary manner with an etherifying agent into a methoxy or ethoxy group or the rest.

- OCH ₂ CONH ₂ or - OCH ₂ COOC, H,

transferred or the keto group in the 4-position Injectedly reduced to a hydroxyl group.

The cyclization of the ketones of the general formula II is under the action of basic or acid catalysts carried out. The catalysts used are preferably alkalis such as sodium or potassium hydroxide, sodium amide, sodium hydride, basic salts such as sodium acetate or sodium carbonate, buffer solutions, for example those made from citric acid and disodium phosphate or from potassium dihydrogen phosphate and borax or from boric acid, sodium hydroxide and potassium chloride, organic bases such as piperidine, pyridine, tetramethylguanidine, benzyltrimethylammonium hydroxide, mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, organic sulfonic acids such as toluenesulfonic acid or camphorsulfonic acid. The reaction is preferably carried out in the presence of an inert solvent, such as methanol, ethanol, dioxane, tetrahydrofuran, ethyl acetate, optionally also in mixtures of these Solvent with each other or with water. The reaction takes place at room temperature, faster with heating, optionally up to the boiling point of the solvent used and is usually finished after a few minutes to a few days.

For the implementation it is not necessary to have the connection of the formula II to be used as such, but you can do this in situ, for example by reaction of a corresponding 2-hydroxy-propiophenone substituted in the 5-position with a corresponding one Treat the product obtained p-alkoxybenzaldehyde directly with the cyclizing agent.

In the ketone to be used, the phenolic hydroxyl group can also be present in protected form, for example as an ester or as a tetrahydropyranyl ether, the cyclization among those Can carry out conditions that the protective group is split off.

The reduction of the corresponding flavone derivatives of the general formula III can be carried out, for example, by catalytic hydrogenation, although usually contains mixtures of the corresponding flavones and 4-hydroxyflavans. It is z. B. under ver j use of Raney nickel or copper-chromium oxide in methanol or ethanol, advantageous if higher Hydrogenated temperature using pressure (up to 250 at).

The reduction of the relevant flavone derivative of the general formula III can also be carried out in such a way that at the same time the keto group in the 4-position is reduced to a CHOH group, for example by reduction with sodium or aluminum amalgam or with Raney nickel in aqueous alcohol , it being possible to work at room temperature or in the warmth or boiling point; the implementation is finished after _1/2 hour to 3 days.

If the process product contains a protected hydroxyl group, this is carried out in the usual way Hydrolysis or reduction set free again. For example, one can use esterified or tetrahydropyranyl ethers hydrolyze protected hydroxyl groups or split benzyloxy groups hydrogenolytically.

The optionally to be carried out reduction of the keto group in the 4-position of a compound of general formula I can, for example, by catalytic hydrogenation in the presence of platinum oxide in glacial acetic acid or ethanol or by reaction with aluminum amalgam or with complex hydrides such as lithium aluminum hydride, optionally in the presence of aluminum chloride or sodium borohydride.

The new compounds can be mixed with conventional drug carriers in human or veterinary medicine can be used. The carrier substances used are organic or inorganic Substances in question that are suitable for parenteral, enteral or topical application and those with the new compounds do not react, such as water, vegetable oils, polyethylene glycols, Gelatine, milk sugar, starch, magnesium stearate, talc, petroleum jelly, cholesterol, etc. For parenteral use Application are in particular solutions, preferably oily or aqueous solutions, as well as suspensions, Emulsions or implants. For enteral application, tablets or dragees, for topical application ointments or creams, optionally sterilized or with auxiliary substances, such as Preservatives, stabilizers or wetting agents or salts to influence the osmotic Pressure or with buffer substances are applied.

The dosage of the substituted flavan derivatives according to the invention is preferably 1 to 500 mg.

example 1

A solution consisting of 2.5 g of 2.5 _T dihydroxypropiopherion-5-tetrahydropyranyl ether, which by

30-minute boiling of 2,5-dihydroxy-propiophenone with dihydropyran and a few drops of hydrochloric acid has been obtained, 1.9 g of p-isoamyloxybenzaldehyde and 19 ml of ethanol are shaken with 12 g of hot 50% sodium hydroxide solution for 5 minutes, water is added and the resulting 3-Methyl-6- (tetrahydropyranyl-2-oxy) -4'-isoamyloxyflavanone was filtered off. This crude product is _{boiled for 2 and 2} hours in 5% strength aqueous alcoholic hydrochloric acid, stirred into water, and the mixture is extracted with chloroform. After evaporation of the chloroform, the crude 3-methyl-6-hydroxy-4'-isoamyloxy-flavanone is obtained, which melts at 198 to 199 ° C. after recrystallization from ethanol. The yield is 2.1 g.

The tetrahydropyranyl ether of 3-methyl-6-hydroxy-4'-methoxy-flavanone is obtained in an analogous manner, and the free 3-methyl-6-hydroxy-4'-methoxy-flavanone is obtained therefrom by treatment with aqueous methanolic hydrochloric acid; F. 189 to 190 ⁰ C.

Example 2

A hot ethanolic solution of 1.7 g of 2,5-dihydroxypropiophenone and 1.4 g of anisaldehyde are mixed with 8 ml of piperidine and left to stand at 25 ° C. for 6 days. The mixture is then stirred into water, the 3-methyl-6-hydroxy-4'-methoxyflavanone obtained suctioned off, washed with water and recrystallized from benzene; M.p. 189 to 190 ° C; yield 2.9 g.

Example 3

1.7 g of 2,5-dihydroxypropiophenone and 1.5 g of anisaldehyde are dissolved in 15 ml of ethanol, 15 ml of ethanol are dissolved, 15 g of potassium hydroxide in 10 ml of water are added and the mixture is left to stand for 2 days at room temperature. The reaction mixture is stirred into water, acidified to pH 6 with dilute hydrochloric acid and extracted with chloroform. The extract is washed with water, dried with sodium sulfate and the solvent is distilled off. The residue is dissolved in 60 ml of ethanol, a solution of 12 g of sodium acetate in 30 ml of water is added and the mixture is boiled on the steam bath for 2 hours. The ethanol is distilled off and water is added to the residue. It is then extracted with ether, the organic phase is washed with water, dried over sodium sulfate and the solvent is distilled off in vacuo. The 3-methyl-6-hydroxy-4'-methoxy-flavanone is recrystallized from benzene; M.p. 189 to 190 ⁰ C; Yield 2.7g.

Analogously one obtains from

2 - hydroxy - 5 - ethoxy - propiophenone, made from 2,5 - dihydroxypropiophenone and diethyl sulfate with p-isoamyloxybenzaldehyde

3 - methyl - 6 - ethoxy - 4 '- isoamyloxy - flavanone, mp 119 to 120 ° C (methanol).

Example 4

1.5 g of 2 ', 5'-dihydroxy-4-methoxy-a-methyl-chalcone, the condensation of anisaldehyde with 2,5-dihydroxy-propiophenone, as described in Example 3, but isolated after standing overnight at room temperature heated in 70 ml of ethanol together with 0.5 g of camphor sulfonic acid for 2 hours at 130 ° C in a sealed tube. When the reaction mixture cools, 3-methyl-6-hydroxy-4'-methoxy-flavanone separates and is filtered off with suction and is recrystallized from benzene. 189-190 ° C. Yield 1.4g.

B e i s ρ i e 1 5

3 g of 3-methyl-6-hydroxy-4'-methoxy-flavone are dissolved in 70 ml of ethanol with 5 g of Raney nickel as a catalyst Hydrogenated at 85 ° C for 12 hours. The catalyst is filtered off, the solvent is distilled off and

ίο the residue is chromatographed on neutral aluminum oxide. Elution with chloroform gives 0.9 g of 3 - methyl - 6 - hydroxy - 4 '- methoxy - flavanone (M.p. 189 to 190 ° C) and 1.0 g of 3-methyl-4,6-dihydroxy-4'-methoxy-flavan (M.p. 222 to 223 ° C) in addition to unchanged starting material.

B e i s ρ i e 1 6

1 g of 3-methyl-6-hydroxy-4'-isoamyloxy-flavone and 0.4 g of 5% palladium-carbon are in 40 ml of tetralin Heated to 200 ° C for 2 hours. It is then cooled, the catalyst filtered off and the filtrate with 5% Sodium hydroxide solution extracted. The extract is washed three times with a little ether and acidified, whereby the crude 3-methyl-6-hydroxy-4'-isoamyloxyflavanone precipitates. By recrystallization from aqueous Ethanol, the pure compound is obtained with a temperature of 198 to 199 ° C. The yield is 0.4 g.

Example 7

A mixture of 1 g of 3-methyl-6-hydroxy-4'-methoxy-flavanone and 0.3 g of sodium borohydride in 30 ml Ethanol is stirred for 10 hours at room temperature, then acidified with a little acetic acid and im Reduced vacuum. The 3-methyl-4,6-dihydroxy-4'-methoxyflavan which precipitates out is recrystallized again from ether; M.p. 222 to 223 ° C; yield .0.3 g.

The following can be produced in the same way:

S-MethyM-hydroxy-o-ethoxy ^ '- isoamyl-flavan, 188 ° C .;

3-methyl-4,6-dihydroxy-4'-isoamyl-flavan,
M.p. 200 to 201 ° C.

B is ρ i el 8
^y

1 g of 3 - methyl - 6 - hydroxy - 4 '- isoamyloxy - flavanone and aluminum amalgam (from 3 g of aluminum foil) are boiled in 100 ml of 80% ethanol for 6 hours. The catalyst is filtered off and the solution is concentrated in vacuo, the 3-methyl-4,6-dihydroxy-4'-isoamyloxy-flavan crystallizing out; M.p. 200 to 201 ⁰ C; Yield 0.2g.

B ei s ρ i e 1 9

In 50 ml of absolute acetone, 5.7 g of 3-methyl-6-hydroxy-4'-methoxy-flavanone, 2 g chloroacetamide and 2.6 g anhydrous potassium carbonate cooked for 72 hours. Then water is added and extracted with ether. The ethereal phase is separated, the precipitate which separates out of the water phase is suctioned off and dried. By recrystallization pure 3-methyl-4'-methoxyflavanon-6-oxyacetic acid amide is obtained from ethanol receive; M.p. 193 to 194 ° C; Yield 5.2g.

Example 10

2.85 g of 3-methyl-6-hydroxy-4'-methoxy-flavanone, 1.75 g of ethyl bromoacetate and 1.3 g of water

free potassium carbonate are treated analogously to Example 9. 3-Methyl-4'-methoxyflavanone-6-oxyacetic acid ethyl ester is made from ether obtained crystalline; M.p. 92 to 93 ° C; Yield 2.95g.

Example 11

A suspension of 0.6 g of lithium aluminum hydride in 60 ml of absolute ether is added with stirring a solution of 3 g of 3-methyl-6-ethoxy-4'-isoamyloxy-flavanone in 60 ml of absolute ether was added dropwise. After refluxing for 30 minutes, the excess lithium aluminum hydride is removed with ethyl acetate destroyed, the reaction mixture mixed with water and acidified with 2η hydrochloric acid. The severed one aqueous phase is extracted with ether, washed the combined organic phases with water and dried over sodium sulfate. The 3-methyl-4-hydroxy-6-ethoxy-4'-isoamyloxy-flavan obtained melts at 188 ° C (from acetone); Yield 1.3g.

Analogously, 3-methyl-6-hydroxy-4'-methoxy-flavanone is reduced to 3-methyl-4,6-dihydroxy-4'-methoxy-flavan; M.p. 222 to 223 ° C (from ether).

B e i s ρ i e 1 12

By adding dropwise a solution of 2 g of 3-methyl-6-hydroxy-4'-isoamyloxy-flavanone in 80 ml of absolute tetrahydrofuran in a stirred suspension of 0.4 g of lithium aluminum hydride in 40 ml of absolute ίο Ether analogous to Example 7 becomes 3-methyl-4,6-dihydroxy-4'-isoamyloxy-flavan receive; Mp 200 to 201 ° C (from ether); Yield 0.7g.

Example 13

2.84 g of 3-methyl-6-hydroxy-4'-methoxy-fiavanone are in 250 ml of absolute dioxane with platinum dioxide at room temperature and normal pressure to 3-methyl-4,6-dihydroxy-4'-methoxy-flavan hydrogenated; M.p. 222 to 223 ° C; Yield 1.8g.

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Claims (1)

1 claims: 1. Substituted flavan derivatives of the general formula I. IO in the