NO166228B - HALOGENED CEPHALOSPORINE DERIVATIVES. - Google Patents

Abstract

For the Contracting States : BE, CH, DE, FR, GB, IT, LI, LU, NL, SE 1. A process for the manufacture of acyl derivatives of general formula I see diagramm : EP0030294,P12,F1 in which R represents hydrogen or a readily hydrolyzable ester group, as well as of salts of these compounds and hydrates of these compounds or of their salts by reating a halide of general formula II see diagramm : EP0030294,P12,F2 in which R has the significance given above and Y represents a halogen atom, or a salt of this compound with thiourea and, if desired, converting a compound of formula I obtained into a salt or hydrate or into a hydrate of this salt, characterized in that X signifies one of the groups see diagramm : EP0030294,P13,F3 in which R' represents hydrogen or a readily hydrolysable ether group.

Description

The present invention relates to new halogenated cephalosporin derivatives with the general formula available in syn form

where Y means a halogen atom and X one of the groups

as well as their salts.

The new cephalosporin derivatives with formula II can, for example, be used in the production of cephalosporin derivatives with the general formula available in syn form

where X has the aforementioned meaning, as well as of salts of these compounds and hydrates of these compounds acc. salts. This method is characterized by reacting a cephalosporin derivative of the formula II or a salt of this compound with thiourea and, if desired, transferring a compound of the formula I obtained in a salt or hydrate

respectively a hydrate of this salt.

Group (b) exists in tautomeric equilibrium with group (a).

Examples of salts in the compounds of formula I and II are alkali metal salts such as sodium and potassium salts; the ammonium salt; alkaline earth metal salts such as the calcium salt; salts with organic bases such as salts with amines, e.g. salts with n-ethylpiperidine, procaine, dibenzylamine, N,N<1->dibenzylethylethylenediamine, alkylamines or dialkylamines, as well as salts with amino acids such as e.g. salts with arginine or lysine. The salts can also be monosalts or disalts. The second salt formation can occur in compounds with the hydroxy residue in the 2,5-dihydro-6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl group.

The compounds of formula I likewise form addition salts with organic or inorganic acids. Examples of such salts are the hydrohalides, e.g. hydrochlorides, hydrobromides, hydroiodides as well as other mineral acid salts such as sulphates, nitrates, phosphates and the like, alkyl and mono-aryl sulphonates etc., and also other organic acid salts such as acetates, tartrates, maleates, citrates, benzoates, salicylates, ascorbates etc.

The compounds of formula I (including their salts) may be hydrated. The hydration may occur during the manufacturing process or occur slowly as a result of the hygroscopic properties of a provisionally anhydrous product.

The products according to the invention are available in the syn-isomeric form (Z-form)

in contrast to the anti-isomeric form (E-form) The halogenated cephalosporin derivatives with formula II can be prepared according to the invention, e.g. by a method which is characterized by reacting a primary amine with the general formula where X has the above-mentioned meaning, with a halogenated carboxylic acid with the general formula

where Y is a halogen atom, or with a reactive derivative of this compound. The halogenated carboxylic acid of formula IV is used either in free form in the presence of a condensing agent, e.g. an N,N'-disubstituted carbodiimide, such as N,N<1->dicyclohexylcarbodiimide, or an azolide compound, such as N,N<1->carbonyldiimidazole or N,N'-thionyldiimidazole or also in the form of an acid halide ,

such as acid chloride or bromide, in the form of an acid anhydride, such as acid anhydride, with a carboxylic acid monoester, e.g. with monomethyl or monoisopropyl carbonate, or in the form of an activated ester, such as p-nitrophenyl ester, 2,4-dinitrophenyl ester, N-hydroxysuccinimide ester or N-hydroxyphthalimide ester. The reaction generally takes place in an inert organic solvent, e.g. a halogenated hydrocarbon such as chloroform, dichloromethane, carbon tetrachloride, in an ether e.g. tetrahydrofuran, dioxane, in dimethylformamide, dimethylacetamide, water or mixtures thereof. The reaction temperature is preferably in the range of approx. -50 to + 40°C, preferably at approx. -10 to +10°C.

Halogenated cephalosporin derivatives with formula II according to the invention can also be prepared by a method which is characterized by halogenating a compound with the general formula

where X has the above meaning. The starting product of formula V used here can in turn be prepared by a method which is characterized by reacting the above-defined primary amine of formula III with 3-oxo-2-methoxyiminobutyric acid or with a reactive derivative of this compound. This reaction proceeds in essentially the same way as the above-described acylation of the primary amine with the halogenated carboxylic acid of formula IV or with a reactive derivative thereof. The halogenation of the obtained acylation product of formula V leads to the above-defined halides of formula II and preferably takes place by treatment with the corresponding halogen or thionyl halide, e.g. with chlorine,

bromine or sulphuryl chloride, preferably in an inert solvent, such as a halogenated hydrocarbon, e.g. dichloromethane, dichloroethane, chloroform, dichloroethylene, carbon tetrachloride or a lower alkane carboxylic acid such as acetic acid, an aromatic solvent such as benzene or toluene. The reaction temperature is generally between approx. (<T>C and 60 "C.

The above-described reaction of the halide with formula II or according to the invention, a salt thereof with thiourea preferably proceeds in an inert solvent, such as e.g. in a lower alkanol, e.g. ethanol, in a lower ketone, such as acetone, in an ether, such as tetrahydrofuran, dioxane, in dimethylformamide, dimethylacetamide, in water or in mixtures thereof. The reaction temperature is generally in the range of approx. 0°C to 60°C, preferably at room temperature. Chloride, bromide, fluoride or iodide can be used as halide with formula II, preferably the chloride or bromide is used. The free acid of formula II can be used, but optionally also a salt thereof, the same salts as the above-mentioned salts of the compounds in formula I being considered.

Preparation of the salts and hydrates of the compounds of formula I or the hydrates of these salts can take place in a manner known per se, e.g. by reacting the carboxylic acid of formula I with an equivalent amount of the desired base, suitably in a solvent, such as water or in an organic solvent, such as ethanol, methanol, acetone and others. By using a further equivalent of the base, salt formation also takes place on a possibly present tautomeric enol form (2,5-dihydro-6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl group X), as a disalt. The salt formation temperature is not critical. It is generally at room temperature, but can easily be above or below this, roughly in the range of 0°C to +50°C. Preparation of the salts of the compounds of formula II takes place in an analogous manner.

The production of the hydrates mostly occurs automatically during the production process or as a result of hygroscopic properties of a provisionally anhydrous product. In an intentional production of a hydrate, a completely or partially anhydrous product (carboxylic acid with formula I or ester, ether or salt thereof) can be exposed to a moist atmosphere, e.g. at approx. +10°C to +40°C.

Any obtained syn/anti mixture of a compound of formula I can be split in the usual way into the corresponding syn and anti forms, e.g. by recrystallization or by chromatographic methods using a suitable solvent or solvent mixture.

The compounds of formula I as well as the corresponding salts or hydrates of these products are antibiotically active, particularly bactericidally active. They have a broad spectrum of action against gram-positive and gram-negative microorganisms, including e-lactamase-producing staphylococci and various e-lactamase-producing gram-negative bacteria such as e.g. Pseudomonas aeruginosa, Haemophilus influenzae, Escherichia coli, Serratia macescens, Proteus and Klebsiella species.

The compounds of formula I as well as the corresponding easily hydrolyzable esters, ethers and the salts respectively the hydrates of these products can be used for the treatment and prophylaxis of infectious diseases. For an adult, a dose of about 0.1 g comes to about 2 g per day in consideration. The parenteral administration of the compounds according to the invention is particularly preferred.

To demonstrate the antimicrobial activity of said products, the in vitro activity (minimum inhibitory concentration in pg/ml) was determined for (6R,7R)-7-[2-(2-amino-4-thiazolyl)-2-(Z -methoxyimino)acetamido]-3-[[(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl)thio]methyl]-8-oxo-5-thia- 1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (hereinafter denoted by A), a representative example of the process products obtained according to the invention. The result is summarized in the following table:

The antibacterial effect in vivo was determined as follows:

Groups of 5 mice are infected intraperitoneally with an aqueous suspension of Escherichia coli. Three times, i.e. 1 hour, 21 hours and 4 hours after the infection, the test substance is applied in physiological saline solution. The number of surviving animals is determined on the 4th day. Different dosages are applied, and by interpolation the dose at which 50% of the test animals survive is determined (CD50, mg/kg).

The products with formula I can be used as pharmaceuticals, e.g. in the form of pharmaceutical preparations which may contain these or their salts in admixture with a pharmaceutical, organic or inorganic inert carrier material suitable for enteral or parenteral application such as e.g. water, gelatin, gum arabic, milk sugar, starch, magnesium stearate, talc, vegetable oil, polyalkylene glycols, vaseline, etc. The pharmaceutical preparations can be in solid form, e.g. as tablets, dragére, suppositories, capsules; or in liquid form, e.g. as solutions, suspensions or emulsions. They may be sterilized and/or contain auxiliary substances such as preservatives, stabilisers, wetting agents or emulsifiers, salts to change the osmotic pressure, anesthetics or puffs. They may also contain other therapeutically valuable substances. The compounds of formula I and the salts respectively the hydrates thereof are preferably intended for parenteral application and are prepared for this purpose preferably as lyophilisates or dry powders for dilution with common agents, such as water or isotonic saline.

Example 1

37.1 g (7R)-7-amino-3-desacetoxy-3-/"(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl)-tiq7- cephalosporanic acid is suspended in 800 ml of acetic ester and 100 ml of N,O-bis-(trimethyl-silyl)-acetamide is added. The mixture is stirred under the exclusion of moisture for 30 minutes at 25° C., whereby a light yellow solution is formed. In this to -10°C cooled solution, a solution of (Z)-4-bromo-2-methoxyimino-3-oxo-butyric acid chloride, which is prepared from 22.4 g of (Z)-4-bromo-2- methoxyimino-3-oxo-butyric acid in 300 ml of alcohol-free and anhydrous dichloromethane and 20.8 g of phosphorus pentachloride at 8-10°C,

for 30 minutes at minus 10 to 0°C. The reaction mixture is stirred for 30 minutes at 0-5°C and 1 hour at 25°C. 1 liter of vinegar and 500 ml of water are added while stirring. The aqueous phase and the resinous intermediate layer are discarded. The organic phase is washed six times with 500 ml each of water/dried with sodium sulfate and reduced under vacuum at 40°C to a volume of 200 ml. This orange colored concentrate is added dropwise to 1.8 liters of ether with stirring, whereby the reaction product precipitates out amorphously. This is filtered off, washed with 1 liter of ether and 1 liter of deep-boiling petroleum ether and dried overnight under vacuum at 35°C. 37.2 g (64.4

% theoretical yield) (6R, 7R) -7-/4-bromo-2-/"(Z)-methoxyyiminq7aceto-acetamideq7-3-/2r(2» 5-dihydro-6-hydroxy-2-methyl- 5-oxo-as-triazin-3-yl)thio7methyl/-8-oxo-5-thia-1-azabicyclo/*4.2.O/oct-2-en-2-carboxylic acid as beige, amorphous product with / "°c./D

= -2 23.1° (c = 1 in methanol. <1>H-NMR spectrum in DMSO-dg ( 6 -values in ppm, s = singlet, d = doublet, q = quartet,

b = wide; J = coupling constant in Hz; proton number in brackets) : 3.60 (N-CH3) (s) (3), 3.63 (2-CH-) (AB-q/centering value; Jgem = 18 Hz) (2), 4.07 £= N^0Cf*3, {Z)J (s) (3), 4.25 (3-CH--S) (AB-q/centering value; J em =13 Hz) (2),

2 ^ ^ gem ' 4.62 (Br-CH2-) (s) (2), 5.15 (H-6) (d,JH_g H_?= <5> Hz) (1), 5.78 (H -7) (q,JH_7;NH = 8 Hz, JH_7/H_6 <=><5>'<hz>) (1), 9.47 (NH)

(<dJ>NH>H_7= 8 Hz) (1), 11,12 (-COOH and -OH) (b) (2).

The (Z)-4-bromo-2-methoxy-imino-3-oxo-butyric acid used as starting compound can be prepared as follows: 592.1 g of acetoacetic acid tert-butyl ester is dissolved in 560 ml of glacial acetic acid. In this solution, it is dripped at 5-10°C

during 2\ hours a solution of 290.6 g of sodium nitrite in 655 ml of water. The resulting yellow suspension is stirred for 30 minutes at 20°C, 940 ml of water is added and stirred for a further 2 hours. The mixture is added to 900 ml of water and 900 g of ice and extracted in the mixing vessel three times with 1 liter of ethyl acetate. The combined ethyl acetate extracts are washed three times with 1 liter of water, then 5 liters of water are added,

and with sodium bicarbonate the pH value is adjusted to 6.8. After the separation of the aqueous phase, it is washed once more with water. The ethyl acetate solution is then dried over sodium sulphate and evaporated under vacuum at 40°C. (A)-2-hydroxyimino-3-oxo-butyric acid tert-butyl ester is obtained as a yellow oil which is dried for a further 9 hours under high vacuum at 40°C. The yield is 626.65 g (89.2% theoretical yield).

626.65 g of (Z)-2-hydroxyimino-3-oxo-butyric acid tert-butyl ester are dissolved in 2.86 liters of acetone. The solution is cooled to 5°C and 703.5 g of potassium carbonate is added in portions. 322 ml of dimethylsulphate are then dripped into the yellow suspension without cooling over the course of 1 hour, whereby the temperature of the mixture should not rise above 25°C. The light beige suspension is stirred at 20-25°C for approx. 4 hours, until no starting material can be detected by thin-layer chromatography. The mixture is then poured into 7 1 of water and extracted with 1 liter of ethyl acetate. The combined ethyl acetate extracts are washed three times with 1 liter of water, dried over sodium sulphate and evaporated under vacuum at 40°C. The remaining yellow oil is dried for a further 6 hours under high vacuum at 40 oC and then distilled. 577 g of (Z)-2-methoxyimino-3-oxo-butyric acid tert-butyl ester (85.6% theoretical yield) are obtained as a yellow oil with a boiling point of 57°C at 0.02 mm Hg . <i>H-NMR spectrum in CDCl3 (6 values in ppm, s = singlet, proton number in parentheses) : 1.55 £-" C (CH3)3^7(s). (9), 2.36 (CH3-CO) (s) (3), 4.01 /=N-<*0CH>3,

(Z) J (s) (3).

86 g of (Z)-2-methoxyimino-3-oxo-butyric acid tert-butyl ester are dissolved in 400 ml of trifluoroacetic acid. The solution is left for 1 hour at 25°C, then evaporated. under vacuum at 35°C. The oily residue is crystallized from ether/petroleum ether. 50 g (80.6% theoretical yield) of yellowish, water-soluble (Z)-2-methoxyimino-3-oxo-butyric acid is obtained from m.p. 80-85°C.

^"H-NMR spectrum in CDCl^ (£ values in ppm, s = singlet, proton number in parentheses): 2.43 (CH3~CO) (3), 4.14

/= N °<CH>3, (Z)_/ (S) (3), 10.47 (OH) (s) (1).

145 g of (Z)-2-methoxyimino-3-oxo-butyric acid are dissolved in 1000 ml of alcohol and anhydrous dichloromethane. 10 ml of 30% hydrobromic acid in glacial acetic acid is added to this solution. Then drip on for approx. 2 hours a solution of 37.5 ml of bromine in 112.5 ml of dichloromethane, whereby the temperature of the reaction mixture is maintained by moderate cooling at 20-25°C.

Nitrogen must now be blown through to remove HBr from the reaction mixture. Then 250 g of ice, 250 ml of water and 2 liters of ether are added one after the other. The aqueous phase is separated and discarded. The organic phase is washed with 250 ml of water and 250 ml of saturated sodium chloride solution, dried with sodium sulphate and evaporated in vacuo. 170 g of brown oil remain, which is crystallized from carbon tetrachloride. One obtains 100 g (44.6% theoretical yield) practically colorless (Z)-4-bromo-2-methoxyimino-3-oxo-butyric acid H-NMR spectrum in CDCL^

(£ -values in ppm, s = singlet, number of protons in parentheses): 4.24 f= N^0CH3, (Z)7 (s) (3), 4.41 (-CH2~) (sO (2), 11.00 (OH) (S) (1) •

Example 2

28.8 g of (6R,7R)-7-[4-bromo-2-(Z-methoxyimino)acetamido]-3-[[(2,5-dihydro-6-hydroxy-2-methyl-5-oxo- as-triazin-3-yl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid is dissolved in 400 ml of absolute ethanol. 7.6 g of thiourea are added to the solution. After 15-20 minutes of stirring at 25°C, the reaction product begins to crystallize as hydrobromide from the orange solution. After VA hours of stirring, the latter is filtered off, washed successively with 200 ml of alcohol and 200 ml of low-boiling petroleum ether and dried overnight in a high vacuum at 35-40°C. 22 g of practically colorless hydrobromide is obtained. This is dissolved in a mixture of 110 ml of water and 110 ml of acetone together with 15.7 g of sodium acetate trihydrate. 150 ml of acetone is added to this solution until a light clouding occurs. Shortly thereafter, the reaction product begins to crystallize. The mixture is stirred for 30 minutes, then added dropwise to 180 ml of acetone for a further 30 minutes, whereby the crystallization becomes complete. The reaction mixture is filtered off, washed successively with 250 ml of 85% aqueous acetone, 250 ml of acetone and 250 ml of low-boiling petroleum ether and finally dried in vacuum at 25°C. 19.6 g (59.3% theoretical yield) of practically colorless disodium salt of (6R,7R)-7-[2-(2-amino-4-thiazolyl)-2-(Z-methoxyimino)acetamido] is obtained -3-[[(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2 .0]oct-2-ene-2-carboxylic acid, which is recrystallized from aqueous acetone. 17.3 g (52.3% theoretical yield) of pure substance with [a]^<5> = -150.8° (c=l in water) is obtained. The compound contains 3.5 mol H2O per moles of substance. 1H-NMR spectrum in DMSO-d6 (S values in ppm, s=singlet, d=doublet, q=quartet, b=broad; J=coupling constant in Hz; number of protons in parentheses): 3.47 (N-CH3 ) (s) (3), 3.94 (2-CH2)

(AB-q/centering value; J = -18 Hz) (2), 3.85 [= n/0CH3,

(Z)] (s) (3), 4.37 (3-CH2-S) (AB-q/centering value; Jgem = 12.5 HZ) (2), 5.04 (H-6) (d, JH_tfH_7 = 4.5 Hz) (1), 5.59 (H-7) (q,JH_7jNH<=><8> Hz, JH_? H_6 ='4.5 Hz) (1), 6.75 (thiazole -yl-H) (s) (1), 7.29 (-NH2)' (b) (2), 9.52 (-C0-NH-)

(d'JNH,H-7 = 8 HZ> W"

Claims (2)

1. Halogenated cephalosporin derivatives present in syn-form, characterized by the general formula where Y means a halogen atom and X one of the groups as well as the salts thereof. 2. Compounds according to claim 1, characterized in that Y is bromine.