FR229M - - Google Patents

Description

FRENCH REPUBLIC

MINISTRY OF INDUSTRY

INDUSTRIAL PROPERTY SERVICE

SPECIAL MEDICINAL PATENT

P.V. No. 836.429 International Classification:

N ° 229 M A 61 k - C 07 d

A-substituted alkoyl penicillins and their salts.

Company known as: Chas. PFIZER & Co. Inc. residing in the United States of America.

Requested on August 22, 1960, at 4:23 p.m., in Paris.

Issued by decree of February 27, 1961.

(Official Bulletin of Industrial Property [BSM], No. 6 of 1961.) (Patent application filed in the United States of America on September 28, 1959, under No. 842,573, in the names of Messrs. Hsing Tsung Huang and Thomas Akiyoshi Seto.) (Patent resulting from the division of invention patent application, PV no. 815,571, filed January 13, 1960.)

The subject of the invention is “.-Substituted alkyl-penicillins and the salts of these penicillins, which constitute novel antibiotic compounds.

The various known penicillinic compounds, which are all commonly obtained by biosynthesis, play a very valuable role in the arsenal of the physician.

The term "penicillin" covers a number of structural compounds:

0

-c-nh-ch-ch '

0 = C — N-

: -ch / N

<

/ CH3

ch3

-ch.cooa in which A denotes hydrogen or a non-toxic saligene radical which differ only in

0

II

the nature of the group attached to —C.

The properties of a particular penicillin are determined by this attached group. The best known and most widespread penicillins are benzylpenicillin and phenoxymethylpenicillin, in which this group is a benzyl or phenoxymethyl radical. Benzylpenicillin, although effective by the parenteral route, has low therapeutic efficacy by the oral route. Phenoxymethylpenicillin, on the other hand, shows therapeutic activity by the oral route. However, its rate of absorption and its subsequent degradation, in the animal organism, into therapeutically inactive products make it desirable to obtain penicillin which does not have these drawbacks.

We have now discovered a series of new α-substituted alkyl penicillins and salts of these penicillins which, although active both by the buccal route and by the parenteral route, are particularly active by the buccal route. The new compounds have a structure different from that of the known phenoxyalkylpenicillins, in that they have a substituent group on the carbon atom adjacent to the penicillin part. These new compounds have the following general formula:

Ri O

k £

-s i II, sx / CH3

Vx-ch-c-nh-ch-ch / \ c <= / i i \ cha

0 = C — N-

—Ch.coor2 (i)

in which R denotes hydrogen, an alkyl, alkoxy, amine, nitro, cyano, hydroxyl or halogen atom, R1 denotes an alkyl radical, R2 denotes hydrogen or a non-toxic saligen radical and X denotes oxygen or sulfur.

The invention encompasses the non-toxic salts of the acidic forms of these new penicillins, i.e. non-toxic metal salts, such as sodium and potassium salts, as well as ammonium and ammonium salts. substituted non-toxic, for example salts of non-toxic amines such as procaine, dibenzylamine, N, N'-dibenzyl-ethylenediamine, 1-epheneamine, N-benzyl- (3-phenethylamine and other amines which have been used to form salts with benzylpenicillin.

It has been found, unexpectedly, that the introduction of an alkyl group into the phenoxy-methyl-penicillin molecule produces penicillins which, although possessing antibacterial spectra similar to that of phenoxymethylpenicillin, both vis-à-vis gram positive microorganisms than gram negative microorganisms,

1 - 41500

Price of the booklet: 1 NF

[229 M] -

characterized by significantly higher blood levels, faster absorption rates and much greater resistance to degradation in the animal body, including in the human body. For example, α-phenoxy-ethylpenicillin and its salts, when administered orally to mice infected with Staphylococcus aureus 5, show a PDgo of 1.5 f * g / kg body weight. When administered to mice, parenterally, a PD50 of 0.78 µg / kg is obtained. Phenoxymethylpenicillin tested under the same conditions and against the same microorganism reveals a PD50 of 2 f / g / kg by oral administration and a PD50 of 1.5 f / g / kg by parenteral administration. The PD50 is the dose, expressed in / xg / kg body weight, that keeps 50% of the test animals alive.

When administered to dogs orally, α-phenoxyethylpenicillin shows a significant increase in blood levels at doses of 10 mg / kg body weight. Table I gives a comparison of the levels of α-phenoxyethylpenicillin in blood serum and of its well-known homologue which is phenoxymethylpenicillin.

Table I Blood level of α-phenoxyethylpenicillin in dogs (Oral administration at 10 mg / kg body weight)

Penicillin

Time in hours

0.5

1

2

3

5

mg / ml

a-phenoxyethyl. . .

3.23

1.326

0.431

0.132

0.006

Phenoxymethyl ...

3.16

1,102

0.345

0.101

0

In humans, significant increases in blood serum antibiotic levels are obtained by the use of α-phenoxyethylpenicillin instead of phenoxymethylpenicillin. Oral administration of α-phenoxyethylpenicillin and phenoxymethylpenicillin to humans at a dose of 250 mg of the antibiotic (calculated as free acid) produces the following levels of antibiotic in blood serum:

(See table opposite)

It is therefore seen that α-phenoxyethylpenicillin produces increased therapeutic effects and has a more sustained action in the animal organism, compared with the effect and action of an equivalent dose of phenoxymethylpenicillin.

Repetition of these blood level tests demonstrates consistency of bactericidal levels

2 -

Table II Levels of a-phenoxyethylpenicillin in human blood

Penicillin

Time in hours

0.5

1

<>

3

ml

Test A

Phenoxymethyl

1.0

1.3

0.6

0.2

a-phenoxyethyl

1.4

3.4

1.8

0.8

Test B

Phenoxymethyl

-

1.4

0.63

0.27

a-phenoxyethyl

-

3.12

1.88

0.95

Dose = 250 mg (as free acid).

high levels and the speed with which therapeutic concentrations are reached with α-phenoxyethylpenicillin. The significant activity by the oral route, together with the greater safety and ease of therapy by the oral route, compared to that by the parenteral route, makes this compound a compound of great value to the profession. medical.

The remaining homologous α-phenoxyalkylpenicillins and analogous phenolmercaptoalkylpenicillins designated by Formula II also show higher blood levels and faster rates of absorption in the animal body.

In addition, these new penicillins are, unexpectedly, much more resistant to degradation to 6-amino-penicillanic acid in the animal organism, including in the human organism, than phenoxymethylpenicillin, for example. Paper chromatographic analysis of human urine samples after oral ingestion of α-phenoxyethylpenicillin revealed a very low presence of 6-aminopenicil-lanic acid in the urine. In addition, 6-amino-penicillanic acid is rapidly detected in the urine of most test subjects after oral administration of phenoxymethylpenicillin. It therefore seems that the alpha substituent on the side chain of penicillin slows down the degradation processes, which give rise to a cleavage of the amide group. The above-described advantageous features of the new penicillins allow the administration of these valuable products in doses of substantially the same order of magnitude, but at shorter intervals than, for example, for phenoxymethylpenicillin. Somewhat smaller doses of the newer penicillins can also be used. The particular regimen and dosage adopted will, however, be fixed by the physician, taking into account the age, weight and condition of the patient.

Valuable products, such as α-phenoxy-ethylpenicillin, are remarkably effective for the treatment of a number of infections in animals, especially in humans. For this purpose, the pure material or mixtures thereof with other antibiotics can be used. For administration to humans and animals, a non-toxic vehicle or carrier is used, i.e. a non-toxic vehicle or carrier when administered in an amount sufficient to provide the required dose of α-Phenoxyethylpenicillin. This vehicle or support can be any pharmaceutical vehicle, for example liquid or solid, in particular water, aqueous ethanol, syrup, physiological serum, glucose, starch, lactose, sodium phosphate. calcium, or animal feed. Administration can be by the oral route or by the parenteral route. However, the oral route is preferred because of the higher contents of active product which it makes it possible to obtain in the blood.

The new "-substituted alkyl penicillins and their salts are prepared by reacting 6-amino-penicillanic acid or a salt thereof, with an alpha-substituted alkanoic acid or a derivative of such an acid containing the group:

Ri 0

Vx-CH-C

rX = /

or reagents forming this group in situ, then, if R2 denotes hydrogen, by reacting, if desired, the product with a base comprising a non-toxic saligenic radical.

These novel α-substituted alkyl penicillins can be prepared by reaction of 6-aminopenicillanic acid with: 1 ° the appropriate substituted alkanoyl chloride such as α-phenoxy-propionyl chloride; 2 ° the appropriate substituted alkanoic acid anhydride, such as α-phenoxypro-pionic anhydride; 3 ° suitable mixed anhydrides, such as t-butoxyformyl-α-phenoxypro-pionic anhydride. The compounds in question can also be prepared by reacting 6-amino-penicillanic acid with a carbodiimide, such as 1,3-dicyclohexylcarbodiimide and the appropriate substituted alkanoic acid, such as α-phenoxypro-pionic acid.

Suitable starting materials are as follows:

Α-Phenoxypropionic acid;

Α-Phenoxybutyric acid;

Α-Phenoxyvaleric acid;

Α-Phenoxyhexanoic acid;

Α-Phenoxyheptanoic acid;

"-Phenylmercaptopropionic acid;

Α-Phenylmercaptobutyric acid;

- [229 M]

Α-Phenylmercaptovaleric acid;

Α-Phenyimercaptohexanoic acid;

Α-Phenylmercaptooctanoic acid;

Α-Phenoxyisobutiric acid;

Α-Phenoxyisovaleric acid;

A-phenylmercaptoisobutyric acid,

as well as their chlorides and anhydrides. "Phenylmercaptoalkanoic acids are prepared as described by Plummerer, Ber. 43,1408 by reacting the desired α-bromoalkanoic acid, such as α-bromopropionic acid, with thio -phenol in neutral solution.

It is preferred to use the reaction of 6-amino-penicillanic acid with the appropriate substituted alkanoic acid chloride, such as α-phenoxy-propionyl chloride, in the presence of an acid acceptor, at neutral pH to moderately alkaline, i.e., pH between about 6.0 and about 9.0, since this procedure provides substantial yields of the desired product.

When prepared in this way, the new penicillins are obtained as sodium or potassium salts. They are easily converted to the acid form by neutralization with a mineral acid, such as sulfuric acid or hydrochloric acid, and they are recovered by filtration or centrifugation of the precipitated acid.

The acidic forms of the new penicillins are in turn readily converted to their salts by reaction with an appropriate base. Thus, by treating the desired penicillin, in aqueous solution, with ammonium hydroxide, the ammonium salt is obtained. Similarly, other salts are formed including the calcium, magnesium, barium, potassium, and sodium salts. In addition, salts of amines, such as procaine, dibenzylamine, N, N'-dibenzylethylenediamine, 1-ephenamine and N-benzyi-p-phenethylamine are prepared by reacting a solution of penicillin suitable in an aqueous or non-aqueous solvent, with the desired amine. Alternatively, the amine salts are prepared in aqueous solution, by reacting a metal salt of the desired penicillin, eg sodium salt, with the desired acidic amine salt, eg amine hydrochloride.

The introduction of substituted alkanoyl groups, such as the α-phenoxypropionyl group, which contain an asymmetric carbon atom, into the 6-amino-penicillanic acid molecule, produces a penicillin with an asymmetric center in the side chain and enables the formation of two new epimeric penicillins. The product isolated from a given reaction mixture consists of a mixture of two stereoisomeric compounds, both of which are biologically active.

The following examples are given to illustrate the preparation of certain compounds forming the subject of the invention.

[229M!] -

Example 1. - To a well-stirred solution of 30 g of 6-aminopenicillanic acid, 400 ml of 3% sodium bicarbonate, 200 ml of acetone and 5 ml of a 50% hydroxide solution sodium, a solution of 20 g of α-phenoxypropionyl chloride (prepared from α-phenoxy-propionic acid and α-phenoxy-propionic acid) is gradually added at 0 ° C at 0 ° C. thionyl) in 100 ml of acetone. The pH is maintained at 7.5 by adding sodium hydroxide. The mixture is stirred at room temperature for thirty minutes after the end of the addition. 200 ml of water are then added and the solution is extracted with an equivalent volume of ether. The ethereal phase is discarded and the pH of the aqueous phase is adjusted to 2.5 with phosphoric acid, after which this aqueous phase is extracted twice with 300 ml of methylisobutyl ketone. The extracts combined with methylisobutyl ketone are then extracted with 300 ml of water and, after having further added 300 ml of water, the pH is adjusted to 6.5 by adding 5N potassium hydroxide. The aqueous phase is separated and dried by freezing, so that the potassium salt of α-phenoxyethylpenicillin is obtained in the form of a powder.

The potassium salt is purified and obtained in crystalline form by dissolving in acetone: water (4: 1) in an amount of 1 g of dry powder per 6.5 ml of the acetone: water mixture, by adding 19 ml of acetone per gram of powder and upon standing at room temperature. The crystallized potassium salt is filtered off with suction, washed with dry acetone and dried in vacuo. Chemical testing of the crystalline product by the hydroxylamine method described by Grove et al., "Essay Methods of Antibiotics," Medical Encyclopedia, Inc. 1955, New York, NY, page 17 revealed that the product was made up for more than 99% by α-phenoxyethyl penicillin potassium salt. The specific optical rotation of a 1% solution in water is [a] f, 5 ° = + 207.

Example 2. - To a well-stirred solution of 0.216 g of 6-aminopenicillanic acid dissolved in 15 ml of water containing 2.1 g of sodium bicarbonate is added a solution of 0.530 g of a-phenoxypropionic anhydride in 10 ml of acetone over ten minutes at room temperature. After half an hour at room temperature, the mixture is acidified to pH 2.2 using phosphoric acid and extracted with ether. The ethereal extract is then passed through a column of silica buffered with phosphate (pH: 6.0) and the column is developed with an ether-methanol solution and eluted with a phosphate buffer diluted to pH: 7.0. The eluate is acidified to pH 2.2 using phosphoric acid and the acidic eluate is extracted with ether. The ethereal extract is then extracted in turn with a dilute solution of potassium hydroxide, after which the potassium salt is recovered by drying by freezing. This salt is further purified as described in Example 1.

Example 3. - To a solution of 0.166 g of α-phenoxypropionic acid in 10 ml of tetrahydrofuran, 0.204 g of 1,3-dicyclohexylcarbodiimide in 5 ml of tetrahydrofuran and a solution of 0.216 g of acid are added. 6-aminopenicillanic acid in 20 ml of a water: tetrahydrofuran (1/1) mixture containing enough sodium bicarbonate, to form a clear solution. The mixture is left to stand at room temperature for one hour. It is then diluted with water, filtered to remove the 1,3-dicyclohexylurea and the 1,3-dicyclohexylcarbodiimide unreacted, after which the procedure is carried out as described in Example 2, except that the sodium hydroxide is used instead of potassium hydroxide. The sodium salt of α-phenoxyethylpemcillme is thus produced.

Example 4. - A solution of α-phenoxypropionic acid (0.330 g) and triethylmin (0.3 ml) in 10 ml of dry acetone is stirred vigorously and cooled to -5 ° C. A solution of t-butyl chlorocarbonate (0.2 ml) in 3 ml of dry acetone is added dropwise, and after fifteen minutes the mixture containing t-butoxyformyl-α-phenoxypropionic anhydride and Triethylamine hydrochloride is cooled to -50 ° C. It is slowly added to a solution of 6-aminopenicillanic acid (0.430 g) in 20 ml of 3% sodium bicarbonate and 5 ml of acetone, the temperature being maintained at 0 ° - 5 ° C. The mixture reacts tional is then allowed to return to room temperature and, after half an hour, the α-phenoxyethylpenicillin produced is isolated, as described in Example 2, in the form of the potassium salt.

Similarly, the following penicillins are prepared:

a-phenoxy-n-propylpenicillin; α-phenylmercaptoethylpenicillin; a-phenoxy-n-butylpenicillin; α-phenoxy-α-methylethylpenicillin.

By working in the same manner, but using ethoxyformic-α-phenoxypropionic anhydride instead of t-butoxyformic-α-phenoxypropionic anhydride, potassium salt of α-phenoxyethylpenicillin is also formed.

Example 5. By operating as described in Example 1, but using the appropriate acyl chloride, the following penicillins are prepared in the form of their potassium salts: a-phenoxy-n-propylpenicillin e; a-phenoxy-n-butylpenicillin; œ-phenoxy-n-pentylpenicillin; a-phenoxy-n-hexylpenicillin; a-phenoxy-n-heptylpenicillin;

- 5

α-phenoxy-α-methylethylpenicillin; α-phenoxy-ji-methylpropyl-penicillin; α-phenyhnercapto-ethylpenicillin; a-phenylmercapto-n-propylpenicillin; a-phenylmercapto-n-pentylpenicillin; a-phenylmercapto-n-heptylpenicillin; a-phenylmercapto-α-methylethylpenicillin; "-Phenylmercapto-p-methyi-propyipeniciliin. Example 6. By acidification of aqueous solutions of the products of Examples 1, 2 and 5 to pH 2.2 with 6N hydrochloric acid, followed by refrigeration for two hours, the acid forms of the penicillins precipitate. The products are recovered by suction filtration, then washed with cold water and dried under vacuum. The following acids are thus prepared: α-phenoxy-n-propylpenicillin; a-phenoxy-n-butylpenicillin; a-phenoxy-n-pentylpenicillin; a-phenoxy-n-hexylpenicillin; a-phenoxy-n-heptylpenicillin;

a-phenoxy-a-methylethyl-p-enicillin; a-phenoxy-fS-methylpropyl-penicillin; α-phenylmercaptoethylpenicillin; a-phenylmercapto-n-propylpenicillin; a-phenylmercapto-n-pentylpenicillin; a-phenylmercapto-n-heptylpenicillin; α-phenylmercapto-α-methylethylpenicillin; a-phenylmercapto- [3-methylpropylpenicillin. Example 7. - The sodium and ammonium salts of the products of Example 6 are prepared by neutralizing a suspension of the appropriate penicilla-nic acid (0.001 mol) in 20 ml of water with an equimolar amount of sodium or ammonium hydroxide. The salts are isolated by freeze drying and obtained in crystalline form, as described in Example 1.

Example 7. 0.001 mol of N, N'-dibenzylethyl-enediamine hydrochloride in 20 ml of water is added 0.001 mol of each of the products of Example 5 in 10 ml of water. The mixture is stirred vigorously and the salts of N, N'-dibenzylethyl-

- [229 M]

enediamine, which precipitate, are filtered off with suction, washed with water and dried.

Similarly, using an equivalent amount of the appropriate hydrochloride instead of N.N'-dibenzylethylenediamine hydrochloride, amine salts are prepared with the following amines:

Procaine;

Dibenzylamine;

1-ephenamine.

N-benzyl-p-phenethylamine.

Example 9. A solution of 236 mg of procaine base in 10 ml of ethanol is added to 352 mg of α-phenoxyethylpenicillin in 20 ml of methyl isobutyl ketone. After four days of standing at room temperature, the precipitate which forms. form is filtered off with suction, washed with ether and dried. It is identical to the procaine salt of α-phenoxyethyl-penicillin prepared in Example 8.

Similarly, the procaine salt of α-phenyimercaptoethyipenicillin is prepared.

abstract

The subject of the invention is α-substituted alkyl-penicillins, and their salts, corresponding to the following general structural formula:

R1 O

^ —V 1 11 yCHs

C VX-CH-C-NH-CH-CH / \ C <rA == / j J | \ CHa

0 = C-N CH. COOR2

in which R is hydrogen or an alkyl, alkoxyl, amino, nitro, cyano, hydroxyl or halogen radical, R1 is an alkyl, R2 is hydrogen or a radical forming non-toxic salts and X is l oxygen or sulfur.

Company known as: Chas. PFIZER & Co. Inc.

Vicarious :

Plasseraud, Front, Gutmann, Jacqdeun

To sell the booklets, contact the Imprimerie Nationale, 27, rue de la (Convention, Paris (15 *).