CH615931A5 - Process for the preparation of the syn isomer or of a mixture of syn and anti isomers, the content of the syn isomer being at least 90%, of 7-acylaminoceph-3-em-4-carboxylic acids - Google Patents

Abstract

Preparation of the syn isomer or of a mixture of syn and anti isomers, the content of the syn isomer being at least 90%, of antibiotic 7-acylaminoceph-3-em-4-carboxylic acids of the formula I <IMAGE> in which B denotes &rdurule& S or &rdurule& S->O; R<1> denotes furyl, thienyl or phenyl; and R<2> denotes C1-C4-alkyl, C3-C7-cycloalkyl or phenyl and of their non-toxic salts, including their solvates, and esters, by reaction of the corresponding 3-hydroxymethyl compound, optionally with intermediate protection of the 4-carboxyl group, with a carbamoylating agent, to introduce a carbamoyloxymethyl group in the 3-position and subsequent isomerisation of a ceph-2-em compound which may be obtained to the ceph-3-em compound. The compounds are distinguished by a broad spectrum of action against pathogenic microorganisms, resistance against beta -lactamases and by a good stability in vivo.

Description

The invention relates to a process for the preparation of the syn isomer or a mixture of syn and anti isomer, the proportion of the syn isomer being at least 90% of antibiotic 7-acylaminoceph-3-em-4-carbon acids of formula I.

H

H

1

i i

»

R .C.CONH

\

OR

r J-

COOH

(I),

CH20.C0.NH2

wherein

B> S or> S-> 0; 3s

R1 furyl, thienyl or phenyl; and R2 is Ci-C4-alkyl, C3-C7-cycloalkyl or phenyl, and of their non-toxic salts, including their solvates, and esters.

The cephalosporin compounds of the 40 species mentioned at the beginning are named with reference to "Cepham" (J. Amer. Soc. 84 [1962] 3400), the term "cephem" referring to the cepham basic structure with a double bond.

Numerous compounds of the 4s cephalosporin series are known which have a certain antibacterial activity. These compounds have an A3 double bond and are usually substituted in the 3-position by a methyl group or a substituted methyl group and in the 7 β-position by an acylamino group. so

It has now been found that the antibiotic properties of a specific ceph-3-em-4-carboxylic acid are mainly influenced by the nature of the 7-acylamido group and of the substituent in the 3-position. Extensive research has been carried out to find combinations of such groups (in 3- and 7-position) that lead to special antibiotics.

Cephalosporin antibiotics are widely used to treat diseases caused by pathogenic bacteria in humans and animals. For example, they are used to treat diseases caused by other antibiotics, e.g. As penicillins, resistant bacteria are caused, and used in the treatment of patients who are sensitive to penicillin. In 65 many cases, it is desirable to have a cephalosporin antibiotic that has activity against both gram-positive and gram-negative microorganisms

55

having. There have therefore been many attempts to find cephalosporin antibiotics with a broad spectrum of activity.

The practical utility of a significant number of known commercial or experimental cephalosporin antibiotics is limited by their relatively high sensitivity to β-lactamases produced by a variety of bacteria. There is therefore a desire to obtain cephalosporin antibiotics with a broad spectrum of activity, which are characterized by a substantial resistance to β-lactamases, including those which are produced by gram-negative microorganisms.

Another difficulty encountered with many cephalosporin antibiotics intended for therapeutic use is that they are broken down in vivo. It has been found that a considerable number of known cephalosporin antibiotics have the disadvantage that they are often rapidly administered after administration by enzymes present in the body, e.g. B. esterases are inactivated.

A class of cephalosporin antibiotics has now been found which have a special combination of 7β-acylamido groups and substituents in the 3-position, as a result of which the compounds have a good broadband action in conjunction with the desired good β-lactamase stability and good stability is conferred in vivo. These compounds are distinguished by the fact that the 7β-acylamido group is a 2-aryl-2- (etherified oximino) acetamido group which is essentially in the syn configuration, as defined below, and that the substituent in 3- Position is a carbamoyloxymethyl group.

These compounds correspond to the formula I mentioned at the outset and are present as a syn isomer or as a mixture of syn and anti isomer, the proportion of the syn isomer being at least 90%. Products which are essentially free of anti-isomer are particularly preferred.

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With regard to the configuration of the OR2 group with respect to the carboxamido group, the compounds obtainable according to the invention are referred to as syn (cis) isomers.

According to the suggestion by Ahmad and Spencer (Can. J. Chem. 39 [1961] 1340), this configuration is represented as follows:

R.C.CO.NH—

II

N

The term “non-toxic”, as it is applied here to the salts, which may also be in the form of their solvates, and esters of the compounds obtainable according to the invention, includes those derivatives which are physiologically tolerated at the dosage administered. If the salts are in the form of their solvates, the hydrates are particularly suitable for this.

Salts that can be prepared from the compounds obtainable according to the invention include:

Salts with inorganic bases, such as alkali metal salts, e.g. B. sodium and potassium salts, alkaline earth metal salts, e.g. B. Calcium salts and salts with organic bases, e.g. B. procaine, phenylethylbenzylamine and dibenzylethylenediamine, ethanolamine, diethanolamine, triethanolamine and N-methylglucosa mintsalze.

The salts also include resinates which are obtained, for example, with a polystyrene resin or a crosslinked polystyrene-divinylbenzene copolymer which has amino groups or quaternary amino groups.

s If R1 is a furyl group, this can be a fur-2-yl or a fur-3-yl group. If R1 is a thienyl group, this can be a thien-2-yl or a thien-3-yl group. Of these groups, the fur-2-yl group is preferred.

io Examples of R2 include: methyl, ethyl, t-butyl, cyclopentyl and phenyl.

The compounds obtainable according to the invention are distinguished by a particularly valuable combination of properties and develop a high antibacterial activity against a wide range of gram-positive and gram-negative organisms. The breadth of the spectrum of activity is increased by the particularly high stability of the compounds towards β-lactamases, which are produced by various gram-negative organisms. The compounds show the advantageous property of good stability in vivo, especially against esterases.

The properties inherent in the compounds obtainable according to the invention have their usefulness for the treatment of a large number of diseases caused by pathogenic bacteria in humans and animals.

Of the compounds obtainable according to the invention, (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) methoxyiminoacetamido] -ceph-3-em-4-carboxylic acid (syn isomer) is special to name important connection; this compound 30 corresponds to formula II

15

20th

CH20.C0.NH2

(II),

COOH

which is conveniently in the form of an alkali metal salt, especially the sodium salt. This compound is active against a wide range of gram-positive and gram-negative microorganisms, e.g. B. Staphylococci, including Staphylococcus aureus, Streptococcus pyogenes and Streptococcus vilidans, Diplococcus pneumoniae, Haemophilus influenzae, Neisseria and Clostridia species, Escherichia coli, Klebsiella, Proteus and Enterobacter species, which also shows in vivo in tests, as well as in vitro in vitro. The compound has good in vitro activity at inoculum levels as high as 107 organisms / ml and has particularly high in vitro activity against strains of Haemophilus influenzae, Neisseria gonorrhoeae and Neisseria meningitidis.

The compound has a very high stability against ß-lactamases, which are produced by a number of gram-negative organisms, which is demonstrated, for example, by its in vitro activity against various ß-lactamase-producing strains of Escherichia, Enterobacter and Klebsiella species. The compound is resistant to the action of mammalian esterases and is therefore stable in the bodies of humans and animals, which is demonstrated by the high recovery level of the unchanged compound in the urine. In addition, the compound gives high serum levels after parenteral administration to both humans and animals. It is remarkable that it shows a low serum binding.

For therapeutic applications, it is advantageous to use highly soluble base salts, e.g. B. Alkali metal salts, such as the sodium 45 salt to use, since these are distributed more quickly in the body when administered by injection.

It has been shown that the syn isomer of sodium (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4 carboxylate occurs in a number of such different crystalline forms, including the solvates.

The sodium salt is conveniently prepared by adding a solution of the compound of formula II in a polar organic solvent, e.g. B. dimethyl-55 acetamide, in a mixture of such solvents, e.g. B. a mixture of dimethylacetamide and acetone, or of dimethylformamide and technical or denatured alcohol, or in an aqueous polar organic solvent system, for. B. aqueous acetone, with a slight excess 60 of sodium 2-ethylhexanoate, which in a suitable organic solvent, for. B. an alkanol, such as ethanol, a ketone, such as acetone, a chlorinated hydrocarbon, such as methylene chloride, an ester, such as ethyl acetate, or an ether, such as dioxane, is dissolved, and then 65 collects the precipitated salt. The reaction is conveniently carried out at room temperature. The salt can be precipitated by cooling the solution, e.g. B. accelerated to 4 ° C.

5

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If essentially anhydrous solvents are used in this process, form I of the syn isomer of sodium (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph -3-em-4-carboxylate obtained; this material contains about 1.5% water. However, if the solvent system contains more than about 2% water, Form II salt is obtained which normally contains about 2% water. If the solvent system contains more than about 60% dioxane, Form III of the salt is normally obtained; this material comprises a dioxane solvate containing about 1 mole of dioxane, although the Form Ii salt can be obtained if a water-wet or water-wet solvent system is used at an elevated temperature (e.g. 60-80 ° C). The crystallization of amorphous freeze-dried sodium (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] ceph-3-em-4-carboxylate (syn- Isomer) from correspondingly dry, water-containing or dioxane-rich solvent systems gives the salts of Form I, Form II or Form III in the same way.

Exposing the Form I salt to water vapor (e.g., at 75% relative humidity), the salt absorbs more water and changes its crystalline form, which usually leads to the Form IV salt. The resulting material contains about 4% water (i.e., about 1 mole) and is believed to be a hydrate. This change is reversible so that the Form IV salt can be converted to the Form I salt by, for example, drying in vacuo over a drying agent such as phosphorus pentoxide. The Form II salt no longer absorbs water when exposed to water vapor, but it can be converted to the Form I salt by heating (e.g., for about 5 minutes) a suspension of the Form II material in almost boiling methanol .

The form III salt obtained by reacting the compound of formula II and the sodium 2-ethylhexanoate in dioxane-rich solvent systems as described above is normally precipitated as a gel which can be dried in vacuo to form a solid. The solid has a low bulk density and is little or no crystalline. However, the Form II crystalline salt can be prepared by treating an aqueous solution of the salt with a substantial excess (e.g., about 8 volumes) of dioxane, if desired together with a minor amount of ethanol, the resulting white acicular crystals being useful after cooling to reduced temperature (e.g. 4 ° C), the product is washed with dioxane and the crystals are dried (e.g. in vacuo at 20 ° C).

The salt of form III is hygroscopic and if it is exposed to water vapor (e.g. at 75% relative humidity), it loses all the dioxane present and forms the material of form IV, which can then be dried (e.g. over phosphorus pentoxide) to give the Form I salt. When the crystalline Form III material is treated in this way, the crystal habit of the product appears to be maintained through the transformation sequence. The Form III salt can also be converted to the Form I salt by heating a suspension of the Form III material in almost boiling methanol; this conversion leads to a loss of crystallinity when crystalline material of the form in is used.

The four forms of sodium (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylate (syn-isomer) , which have been described above, are characterized by the following X-ray powder patterns (d distances and intensities) and IR spectroscopic

Characterized data:

X-ray powder diagram

Camera - Debye-Scherrer, radius 114.6 mm

Irradiation - copper Ka = 1.5418 Â

Intensities (I) by visual comparison with calibrated

default

Formi d

I.

d

I.

8.33

80

3.05

4th

7.44

4th

2.93

14 (wide)

6.85

45

2.72

8 \ hardly

6.38

5

2.69

10 J resolved

5.86

4th

2.57

9

5.36

4th

2.47

6

4.82

100

2.40

10th

4.56

35

2.35

10th

4.36

6

2.26

4th

4.19

40

2.20

3rd

3.95

26

2.11

8 (wide)

3.82

24th

2.04

3rd

3.62

28

1.94

4th

3.47

28

1.89

5

3.32

10th

1.82

6 (wide)

3.19

10th

1.77

2nd

Form II

d

I.

d

I.

8.78

60

3.49

14

7.81

9

3.07

6 (wide)

6.65

25th

2.91

8th

4.68

100 (wide)

2.77

6

4.45

10th

2.32

3 (wide)

4.20

10th

2.19

2nd

3.76

20 (wide)

2.08

2nd

Form III

d

I.

d r

14.98

60

4.29

20th

12.95

40

4.16

100

10.16

20th

3.81

25 (wide)

8.23

45

3.60

20th

7.52

5

3.47

5

6.61

65

3.32

10th

6.08

3rd

3.26

30th

5.57

20th

3.13

17 (wide)

4.98

40

2.43

10th

4.73

60

2.15

15

Form IV

d

I.

d

I.

8.85

70

3.75

35

7.80

6

3.10

1

7.15

25th

2.93

4th

6.01

20th

2.76

12

5.06

18th

2.62

1

4.65

100

2.41

2nd

4.30

25th

2.30

3rd

4.01

25th

s

10th

15

20th

25th

30th

35

40

45

50

55

60

65

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6

IR spectra

Spectrometer - Perkin-Elmer 521, range 4000 - 650 cm-1 spectra recorded in Nujol (the 3ands assigned to the Nujol were excluded).

Shape!

3520 w

* 1590 s

1262 m

1004 m

3460 m

1556 m

1248 m

978 m

3370 m

1534 s

1170 m

918 w

3265 s

1480 m

1152 m

882 s

1770 sh

1410 s

1134 w

878 sh

1752 s

1400 s

1112m

838 w

1706 s

1338 s

1076 m

814 w

1660 s

1328 s

1054 sh

790 w

1620 s

1284 m

* 1042 s

778 w

754 m

Form II

3526 m

1544 p

1152 m

920 w

3492 w

1478 m

1142 m

882 m

* 3364 m

1412 s

1112 m

878 w

3250 m

1398 s

1080 m

840 w

1758 p

1332 s

1058 m

818 w

1695 s

1284 m

* 1045 m

792 w

1665 p

1268 m

1005 m

752 m

1642 sh

1240 m

980 m

1624 s

1172 m

954 w

Form III

3465 m

1532 s

1155 m

820 w

3415 m

1482 m

* 1124 s

800 w

3345 m

1412 s

1078 m

790 w

3275 m

1395 s

* 1058 s

768 m

3200 m

1326 s

1048 s

748 m

1780s

1285 m

1014 m

1702 s

1260 m

985 m

1660 s

1230 m

938 w

1632 m

1225 m

888 m

1618 p

1196 w

878 s

1552 m

1180 m

836 w

Form IV

3585 w

1594 s

1264 m 1008 m

788 w

3520 w

1555 m

1240 m 980 m

752 m

3370 m

1540 m

1172w 956w

* 3260 s

1478 m

1152 m 920 w

1758 p

1410 s

1114 w 882m

1712s

1400 s

1078 m 878 w

1664 p

1330 s

1058 m 838 w

1620 s

1285 m

1042 m 818 w

Key s = strong sh = shoulder m = medium w = weak

* denotes bands that are characteristic of each crystalline form.

Are insoluble salts of compounds of formula I desired for certain applications, e.g. B. for depot preparations, they can be prepared in a conventional manner, for example using an organic amine.

The compounds of formula I are prepared using the method defined in the characterizing part of patent claim 1.

The subsequent conversion of the compounds of the formula I into their non-toxic salts and esters can be carried out in a conventional manner. For example, the sodium and potassium salts can be prepared by reacting the cephalosporic acid with sodium or potassium 2-ethylhexanoate. Biologically acceptable esters can be obtained using conventional esterification agents.

In addition, if desired, the 1-oxides can be treated by treating the corresponding 1-sulfide with a suitable oxidizing agent, e.g. B. a peracid, such as metaperiodic acid, peracetic acid, monoperphthalic acid or m-chloroperbenzoic acid, or tert-butyl hypochlorite, conveniently in the presence of a weak base such as pyridine.

The carbamoylating agents suitable for carrying out the process according to the invention include isocyanates of the formula VIII

R13-NCO (VIII),

wherein R13 is an unstable, i.e. H. easily removable, substitutes means.

These isocyanates lead to the formation of an N-protected carbamoyloxymethyl group of the formula

-CH2O-CO-NHR13

in 3 position. This group can then be converted into the desired unsubstituted carbamoyloxymethyl group by subsequent elimination of the substituent R13.

The easily removable groups R13 include: chlorosulfonyl, bromosulfonyl; Aralkyl, e.g. B. benzyl, p-methoxybenzyl and diphenylmethyl; tert-butyl; halogenated Niederalka-noyl, e.g. B. dichloroacetyl and trichloroacetyl; and halogenated lower alkoxycarbonyl, e.g. B. 2,2,2-trichloroethoxycarbonyl. With the exception of aralkyl groups such as diphenylmethyl, groups of this type can be hydrolyzed by acid or base catalyzed e.g. B. by base-catalyzed hydrolysis using sodium bicarbonate.

Halogenated groups such as chlorosulfonyl, trichloroacetyl and 2,2,2-trichloroethoxycarbonyl can also be removed reductively and groups such as chloroacetyl can also be split off by reaction with thioamides such as thiourea.

Aralkyl groups, such as diphenylmethyl, are conveniently obtained by treatment with acid, e.g. B. a strong organic acid such as trifluoroacetic acid.

The carbamoylating agent of formula VIII can, if desired, in excess, e.g. B. at least 1.1 mol, based on the compound of formula V. The carbamoylation can by the presence of a base, e.g. B. a tertiary organic base, such as a Triniederal-kylamin, z. B. triethylamine, or by using the acid of formula V in the form of an alkali metal salt, e.g. B. the sodium salt, are supported. Such support of the carbamoylation reaction is not necessary, however, if more active isocyanates, i. H. Compounds of formula VIII, wherein R13 is a strongly electron-withdrawing group, e.g. B. chlorosulfonyl or trichloroacetyl means.

Carbamoylation reactions which involve the reaction of a free acid of formula V with an excess of an isocyanate of formula VIII, wherein R13 is a strongly electron-withdrawing group, e.g. B. means a chlorosulfonyl or Trichlorace-tylgruppe are thanks to the simplicity of the reaction conditions of particular practical advantage, since at s

10th

15

2 «

25th

30th

35

40

45

50

55

60

65

the need to protect the 4-carboxyl group as an intermediate is eliminated and the substituent R13 is easily formed from the N-protected 3-carbamoyloxymethyl compound which has formed in the meantime, e.g. B. can be removed by hydrolysis with aqueous sodium bicarbonate.

To avoid undesired side reactions, it may also be expedient to maintain or even introduce the N-substituting group R13 during the conversion of 3-carbamoyloxymethyl compounds which have formed in the meantime.

Another suitable carbamoylating agent is cyanic acid, which is conveniently prepared in situ, e.g. B. from an alkali metal cyanate such as sodium cyanate. The reaction is carried out by the presence of an acid, e.g. B. a strong organic acid, such as trifluoroacetic acid, relieved. The action of cyanic acid corresponds to that of a compound of the formula VIII in which R13 is hydrogen and accordingly effects the direct conversion of a compound of the formula V into its 3-carbamoyloxymethyl analogue.

The 3-hydroxymethyl starting material to be used to carry out the process according to the invention can be prepared, for example, by the processes described in GB-PS 1 121 308 and BE-PS 783 449.

Preferred protective groups for the 4-carboxyl group of the compound of formula V are those groups which can easily be split off at a later stage in the course of the reaction; they advantageously have 1 to 20 carbon atoms. Suitable carboxyl protective groups are known, for example a list of representative protective groups is contained in the aforementioned BE-PS 783 449. Suitable protective groups include, for example, the residues of ester-forming aliphatic and araliphatic alcohols, furthermore the residues of ester-forming phenols, silanols or stannols and symmetrical or mixed anhydride groups derived from suitable acids.

Preferred protected carboxyl groups are, for example, aryl-lower alkoxycarbonyl groups, such as p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl and diphenylmethoxycarbonyl; Lower alkoxycarbonyl groups, such as tert-butoxycarbonyl; and halogeno lower alkoxycarbonyl groups such as 2,2,2-trichloroethoxycarbonyl. The carboxyl protecting groups can then be removed by any suitable methods known from the literature. So the removal of the protective group z. B. in many cases by acid- or base-catalyzed hydrolysis or by enzyme-catalyzed hydrolysis.

If a sulfoxide analogue of a compound of the formula I is obtained at the end of a given preparative reaction sequence, this can be converted into the corresponding sulfide. The transfer can be carried out, for example, by reducing the corresponding acyloxysulfonium or alkyloxysulfonium salt formed in situ. The formation of these salts can e.g. B. by reaction with acetyl chloride in the case of the acetoxysulfonium salt. The reduction can, for example, with the help of sodium dithionite or iodine ions, e.g. B. a solution of potassium iodide in a water-miscible solvent such as acetic acid, tetrahydrofuran, dioxane, dimethylformamide or dimethylacetamide. The reaction can be carried out at a temperature of from -20 to + 50 ° C.

If a ceph-2-em compound is obtained as the reaction product, this can be converted into the desired ceph-3-em compound by treatment with a base.

The antibiotically active compounds obtainable according to the invention can be packaged in a customary manner, analogously to other antibiotics, into pharmaceutical preparations for use in human or veterinary medicine. The assembly is usually done

615 931

using pharmaceutically acceptable carriers or excipients.

The compounds obtainable according to the invention can, for. B. formulated for preparations for injection and provided in the form of single doses in ampoules or in multi-dose containers using a preservative.

The preparations can be in the form of suspensions, solutions or emulsions in oily or aqueous vehicles and contain formulation agents, such as suspending agents, stabilizing agents and / or dispersing agents. The active ingredient can also be in the form of a powder, which is administered with a suitable vehicle, e.g. B. sterile, pyrogen-free water, can be reconstituted.

Preparations intended for use in veterinary medicine can, for example, be formulated as intramammary preparations, it being possible to use bases with rapid or slow release of active substances.

In general, the preparations can have an active ingredient content of 0.1% upwards, e.g. B. 0.1 to 99%, preferably from 10 to 60%. If the preparations are offered in the form of single doses, each unit preferably contains 50 to 1500 mg of active ingredient. In human medicine, the dosage in adults is preferably 500 to 4000 mg per day, depending on the type and frequency of administration.

The compounds obtainable according to the invention can also be used in combination with other compatible therapeutic agents, e.g. B. antibiotics, such as penicillins, other cephalosporins or tetracyclines.

The following examples serve to illustrate the invention. All temperatures are given in ° C. The melting points were determined on a Kofler bench.

example 1

(6R, 7R) -3-carbamoyloxymethyl-7- [2- (for ur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylic acid (syn isomer)

Method (i)

750 ml of acetone were cooled to 0 ° C and treated with 28.8 ml (240 mmol) of trichloroacetyl isocyanate and the solution was cooled to 0 ° C. 45.6 g (120 mmol) (6R, 7R) -7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -3-hydroxymethylceph-3-em-4-carboxylic acid (syn isomer) were added portions of the stirred isocyanate solution were added for 5 minutes, so that the reaction temperature did not exceed 6 ° C. The yellow solution was stirred for a further 15 minutes and 4.5 ml of methanol was added. The solution was concentrated to 60 ml and the concentrate was dissolved in 750 ml of methanol. 45.3 g (540 mmol) of sodium bicarbonate in 600 ml of water were added followed by 4.5 g of activated carbon and the resulting suspension was stirred at room temperature for 2 hours. The activated carbon was removed by filtering through diatomaceous earth and the light yellow filtrate was adjusted to pH 4.5 by adding dilute hydrochloric acid. The solution was concentrated to half volume under reduced pressure and an equal volume of water was added. The pH was adjusted to 2.0 with dilute hydrochloric acid and the product was isolated by filtration, washed with 3 × 150 ml of water and dried in vacuo at 40 ° C. for 16 hours, 37.46 g (73.5%) received the title compound; [ajg1 + 63.7 ° C (c 1.0; 0.2 m pH 7 phosphate buffer), A. max (pH 6 phosphate buffer) 274 nm (e 17 600).

The IR, NMR and microanalytical data confirmed the structure as that of the title compound.

7

5

10th

IS

20th

25th

30th

35

40

45

50

55

60

65

615 931

8th

Method (ii)

A slurry of 3.81 g (9.55 mmol) (6R, 7R) -7- [2- (Fur-2-yl) -2-methoxyiminoacetamido] -3-hydroxymethyl-ceph-3-em-4-carboxylic acid (syn isomer) in 70 ml dichloromethane / 25 ml tetrahydrofuran at 5 ° C was treated with 2.6 ml (25 mmol) dichloroacetyl isocyanate. The reaction mixture was then treated in the same manner as in method (i), whereby 3.36 g (83.0%) of the title compound were obtained; [ct] g> + 63 ° C; Xmax 273.5 nm (e 17800); with the same IR and NMR spectra as the product of method (i).

Method (iii)

A slurry of 19.05 g (50 mmol) (6R, 7R) -7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -3-hydroxymethyl-ceph-3-em-4-carboxylic acid (syn -Isomeres) in 250 ml of dry acetonitrile was treated between 5 and 10 ° C with 6.33 ml (75 mmol) of chlorosulfonyl isocyanate in 80 ml of acetonitrile.

The reaction was stirred at 0 to 5 ° C for 10 minutes and 50 ml of water was added. The mixture was stirred at about 20 ° C. and after 20 minutes a white crystalline solid separated out. Evaporation and filtration gave 18.17 g (85.7%) of the title compound; [a] g> + 62.5 C; Xmax 273.5 nm (s 17820); with the same IR and NMR spectra as the product of method (i). A second shot of 1.88 g (8.6%) of the product with the same constants was obtained on evaporation of the mother liquors.

Method (ii)

The procedure of method (i) was repeated, but the cephalosporinic acid was originally dissolved in N, N-dimethylformamide / industrial methylated alcohols (or denatured alcohols) instead of N, N-dimethylacetamide / acetone, whereby 80% of the title compound obtained had the same properties as the product of method (i). The IR spectrum indicated that the compound was the Form I salt.

io method (iii)

4.24 g (10 mmol) (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylic acid (syn- Isomer) were dissolved in 20 ml of N, N-dimethylacetamide, which had been dried over a molecular sieve (Linde 4A) for 24 hours. To this was added a solution of 2.0 g (12 mmol, recrystallized from dioxane and dried over phosphorus pentoxide) sodium 2-ethylhexanoate in 80 ml of ethyl acetate, which had been dried over a molecular sieve (Linde 4A) for 24 hours. The solution was stirred in a closed vessel for about 15 minutes until crystallization started and was then cooled to 4 ° C. for 1 hour. The product was filtered, washed with ~ 100 ml of dry ethyl acetate and transferred to an oven while still wet with this solvent and dried at 20 ° C in a vacuum over phosphorus pentoxide overnight, giving 3.89 g (87%) of the title compound received.

The IR and NMR spectra of the product matched those of an authentic sample.

Example 2

Sodium- (6R, 7R) -3-carbamoyloxymethyl-7-

[2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylate (syn isomer) Form I 100 g (6R, 7R) -3-carbamoyloxymethyl-7- [2- ( fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylic acid (syn isomer) in 400 ml of N, N-dimethylacetamide / 11 acetone were mixed with 40 g of sodium 2-ethylhexanoate in 200 ml of acetone treated. The mixture was inoculated and stirred at room temperature for 1.25 hours. The product was filtered off, washed with 500 ml of acetone and then slurried with 3 × 300 ml of acetone and finally slurried with ether, giving 101.4 g (92.5%) of the title compound which (after equilibrium in the atmosphere) was 0 , Contained 65 mole equivalents of water; [oi] d + 61 ° C (c 0.5, pH 4.5 phosphate buffer) and Xmax 273 nm E £ 412 (H2O).

The IR and NMR data confirmed the structure as that of the title compound; the IR spectrum indicated that the compound was the Form I salt.

Example 3

Sodium (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -cpeh-3-em-4-carboxylate (syn isomer) Form II Method (i)

0.2 g of coal or animal charcoal were added to a solution of 4.00 g (9.42 mmol) (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylic acid (syn isomer) added in a mixture of 132 ml of acetone and 1.33 ml of water. The suspension was stirred for 30 minutes and filtered through a diatomaceous earth bed, washing the filter bed with 10 ml of acetone. A filtered solution of 1.66 g (10 mmol) of sodium 2-ethylhexanoate in 20 ml of acetone was added to the stirred filtrate over an hour. The resulting suspension was stirred for a further 10 minutes and the white solid was filtered off, washed with 2X25 ml acetone and dried in vacuo to give 4.06 g (93.0%) of the title compound; [a] ö ° + 60 ° C (c 0.91, H2O); Xmax (H2O) 274 nm (e 17400);

35

40

Analysis for Ci6Hi5N4NaOsS. 0.7 H2O (459.0):

C H N Na S H2O

Calculated: 41.8% 3.6% 12.2% 5.0% 7.0% 2.7% Found: 41.0% 3.45% 12.3% 5.2% 6.6% 2, 7% 41.2% 3.6% 12.4% 6.85% 2.7%

Purity by high pressure liquid chromatography 99.4%. The NMR spectrum of the product resembled that of an authentic sample and the IR spectrum indicated that the product was the Form II salt.

Method

16.98 g (40 mmol) (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylic acid (syn- Isomer) were added to a stirred mixture of 333 ml acetone and 8.5 ml water. After treatment with

Activated carbon and filtering this solution were slowly added 7.32 g (44 60 mmol) of sodium 2-ethylhexenoate in 85 ml of acetone over 1 hour. The reaction mixture was stirred for 15 minutes, filtered and the product was washed with 2 × 65 ml acetone and dried in vacuo overnight at 20 ° C., giving 17.95 g (98.5%) of the title compound 65, which Contained 5 moles of H2O. The NMR spectrum of the product matched that of an authentic sample and the IR spectrum indicated that the product was the Form II salt.

Example 4

Sodium (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] ceph-3-em-4-carboxylate (syn isomer) Form III 4.0 g Sodium (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylate (syn isomer) was dissolved in 20 ml of water . 20 ml of industrial methylated alcohols (denatured alcohol) and 160 ml of dioxane were added and the solution was filtered and then set aside at 4 ° C. for crystallization. The very white, needle-shaped crystals were filtered off, washed with 100 ml of dioxane and transferred to an oven while still moist with dioxane, and dried overnight at 20 ° C. in vacuo, 3.96 g (78.5%) of Received title connection. The IR and NMR spectra of the product matched those of an authentic sample.

Example 5

Sodium (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylate (syn isomer) Form IV samples of Form I and Form III of sodium 3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylate (syn isomer), prepared according to method (iii ) of Example 7 and Example 9, respectively, were exposed to moisture (75% relative humidity) for 3 days, whereby the title compound was obtained. The IR and NMR spectra of the products matched those of an authentic sample. Karl Fischer's water analysis showed 4.0 and 3.85% (1 mol of H2O is equivalent to 3.9%).

Example 6

a) t-Butyl- (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylate (syn isomer)

A suspension of 4.4 g of (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylic acid (syn-isomer ) in 200 ml of dry methylene chloride was treated with 6.6 ml of 0-t-butyl-N, N'-dicyclohexylisourea, a pale yellow solution being formed. After 24 hours at 23 ° C, starting material was still present and an additional 3.3 ml of isourea was added. After 48 hours the mixture was filtered and the filtrate was evaporated under reduced pressure. The resulting material was slurried with ether / ethyl acetate to remove residual dicyclohexylurea. The filtrate was washed with saturated aqueous sodium hydrogen carbonate and with water and then evaporated to give 5.2 g of a foam. Chromatography on silica gel with toluene: ethyl acetate = 2: 1 as solvent gave 3.9 g of the title compound as a pale yellow foam, Xmax (ethanol) 275.5 nm (e 18400).

The IR and NMR data confirmed the structure as that of the title compound.

b) t-butyl- (IR, 6R, 7R) -3-carbamoyloxymethyl-

7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylate-l-oxide (syn isomer) 0.3 ml of t-butyl hypochlorite became a vigorously stirred solution of 0.98 g of t-butyl- (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylate in 25 ml Pyridine and 1 ml of water added at -45 ° C. After stirring for 2 minutes, 1 ml of 2N-sulfuric acid was added to the solution and the mixture was immediately poured into 100 ml of 20% (w / v) aqueous orthophosphoric acid. The solution was extracted with 2 X100 ml of ethyl acetate and the combined organic extracts were washed with 100 ml of aqueous

615 931

like to wash NaHC03 and 100 ml water, then dry (MgSO-t) and concentrate in vacuo.

The crude product was chromatographed on preparative silica gel plates, using ethyl acetate as the eluent and the lower component of the S-oxide running before the R-oxide. Extraction of the slower component with ethyl acetate gave 0.27 g (27%) of the title compound.

The IR and NMR data confirmed the structure as that of the title compound.

c) (IR, 6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylic acid 1-oxide (syn isomer) 0.42 g t-butyl- (IR, 6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxy-lat- L-oxide (syn isomer) was dissolved in 5 ml of trifluoroacetic acid and stirred for 8 minutes at room temperature. The solution was evaporated in vacuo to a red oil and dissolved in ethyl acetate: acetone (1: 1, 5 ml) and added dropwise with stirring to 50 ml of petroleum ether (60-80 ° C). The separated solid was collected and dried in a desiccator. The crude product was slurried with ethyl acetate and the liquid phase was decanted off and added dropwise to 50 ml of petroleum ether (60-80 ° C.), giving 150 mg (40%) of the title compound as a colorless solid; Xmax (0.25N NaHCOs) 263.5 (e 15000) and 281nm (e 13700); Vmax (Nujol) 1799 (β-lactam), 1725 and 1716 (COOH and OCONH2), 1684 and 1538 (CONH) and 1060 and 1050 cm-1 (S- »0); x (Me2SO-dö) values include 0.02 (d, J8Hz, CONH), 4.17 (dd, J4 and 8Hz, 7-H), 4.99 (d, J4Hz, 6-H) and 6.09 (s, N-OCHs).

Example 7

(IS, 6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxy-iminoacetamido] -ceph-3-em-4-carboxylic acid 1-oxide (syn-isomer)

To a stirred solution of 2.59 g of sodium (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoaceta-mido] -ceph-3-em-4-carboxylate (syn isomer) (2.59 g) in 25 ml water was added 1.93 g sodium metaperiodate. The solution was stirred at room temperature for 30 minutes and then added by dropwise addition of 2N aqueous hydrochloric acid. The resulting precipitate was collected, washed successively with water, ethanol and ether and dried in vacuo to give 1.63 g of the title compound as a white powder; [a0 + 113 ° C (c 0.86, Me2SO); W (pH 6 buffer) 264.5 (s 17200) and 279 nm (e 15600); Vmax (Nujol) 1770 (ß-lactam), 1740 and 1716 (CO2H), 1688, 1654, 1589 and 1530 (CONH and OCONH2) and 1030 cm-1 (S-> 0), t (Me2SO-de) 0, 60 (d, J 8 Hz, NH), 2.11, 3.19, 3.31 (multiplets, furyl protons), 4.08 (q, J5 and 8Hz, C-7H). 4.87 and 5.45 (ABq, J13Hz, CH2OCONH2), 4.96 (d, J 5Hz, C-6H), 6.08 (s, OCHs), 6.10 and 6.42 (ABq, J 18 Hz, C-2 CHz).

Example 8

(1R, 6R, 7R) - and (IS, 6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyiminoacetamido] -ceph-3-em-4-carboxylic acid-l oxide (syn isomer)

A solution of 1.93 g of sodium periodate in 10 ml of water became a stirred solution of 2.59 g of sodium (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxyi -minoacetamido] -ceph-3-em-4-carboxylate added in 25 ml of water. The mixture was stirred at room temperature for a further 30 minutes and the solution was acidified with 2 ml of 2N HCl. The deposited IS oxide was filtered off, washed with 5 ml of ethanol and 20 ml of ether and dried in a desiccator, giving 1.59 g of a colorless solid,

9

s

10th

15

20th

25th

30th

35

40

45

50

55

60

65

615 931

10th

[<x] d + 110oC (c 1, Me2SO), which was similar to the product described in Example 7.

The mother liquors were saturated with sodium chloride and filtered and the filtrate was extracted with 2 X100 ml of ethyl acetate. The organic extracts were combined, dried (MgSO4) and concentrated in vacuo to give a yellow solid. The crude product was washed with acetone and the insoluble material was removed by filtration. The filtrate was evaporated to dryness and the acetone wash solution again gave 380 mg of the IR oxide, s [oi] d-88 C (c 1, Me2SO), the x values (Me2SO-d6) were similar to those given in Example 6.

B

Claims (19)

615 931 1. A process for producing the syn isomer or a syn isomer is at least 90% of antibiotic active Mixture of syn and anti isomer, the proportion of men 7-acylaminoceph-3-em-4-carboxylic acids of the formula I R.C. CONH \, ° OR CD, CH2O.CO.NH2 COOH bliss B> S or> S- »0; R1 furyl, thienyl or phenyl; and R2 is Ci-Q-alkyl, C3-C7-cycloalkyl or phenyl, and of their non-toxic salts, including their solvates, characterized in that a compound of the formula V 20th R .C.CONH \ OR COOH (V), CH20H the dashed line between the 2-, 3- and 4-position indicates that the compound can be a Ceph-2-em or a Ceph-3-em compound, optionally with intermediate protection of the 4-carboxyl group with a carbamoylating agent to introduce a carbamoyloxymethyl group in the 3-position and, if one started from a ceph-2-em compound, a ceph-2-em compound obtained isomerized to the ceph-3-em compound. 2. The method according to claim 1, characterized in that one obtains the compound of formula I in the form of the syn isomer, which is essentially free of the anti-isomer. 2nd PATENT CLAIMS 3rd 615 931 Phenyl and R2 mean ethyl, goes out and the (6R, 7R) -3-carbamoyloxymethyl-7- [2-ethoxyimino-2-phenyl-acetamido] -ceph-3-em-4-carboxylic acid obtained as the syn isomer wins. 3. The method according to claim 1, characterized in that an isocyanate of the formula VIII is used as the carbamoylating agent R13-NCO (VIII), wherein R13 represents an easily removable substituent. 4. The method according to claim 3, characterized in that one uses a compound of formula VIII, wherein R13 is a strong electron-withdrawing group, and uses this in excess, based on the compound of formula V. 5. The method according to claim 1, characterized in that the carbamoylating agent used is cyanic acid, such as is obtained from an alkali metal cyanate. 6. The method according to claim 1, characterized in that a compound of the formula I obtained is converted into a non-toxic salt, optionally in the form of a solvate. 7. The method according to claim 1 or 6, characterized in that one obtained a compound of Formula I converted into its sodium salt by reaction with sodium 2-ethylhexenoate. 8. The method according to claim 1, characterized in that one starts from a compound of formula V, wherein R1 is fur-2-yl. 9. The method according to claim 1, characterized in that one of a compound of formula V, wherein R2 Means methyl, ethyl, tert-butyl, cyclopentyl or phenyl. 10. The method according to claim 1, characterized in that one of a compound of formula V, wherein R1 4s mean fur-2-yl and R2 methyl, and the (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-methoxy-iminoacetamido] -ceph-3-em obtained carboxylic acid as the syn isomer wins. 11. The method according to claim 1, characterized in that one of a compound of formula V, wherein R1 Fur-2-yl and R2 are phenyl, and the (6R, 7R) -3-carbamoyloxymethyl-7- [2- (fur-2-yl) -2-phenoxy-iminoacetamido] -ceph-3-em- 4-carboxylic acid wins as the syn isomer. 55 12. The method according to claim 1, characterized in that one starts from a compound of formula V, wherein R1 is fur-2-yl and R2 is cyclopentyl, and the (6R, 7R) -3-carbamoyloxymethyl-7- [2- cyclopentyloxi-mino-2- (fur-2-yl) acetamido] -ceph-3-em-4-carboxylic acid as the syn isomer wins. 13. The method according to claim 1, characterized in that one starts from a compound of formula V, wherein R1 is phenyl and R2 is methyl, and the (6R, 7R) -3-carbamoyloxymethyl-7- [2-methoxyimino-2- phe- 65 nylacetamido] -ceph-3-em-4-carboxylic acid as the syn isomer wins. 14. The method according to claim 1, characterized gekennezich-net in that one of a compound of formula V, wherein R1 15. The method according to claim 1, characterized in that one starts from a compound of formula V, wherein R1 and R2 are both phenyl, and the resulting (6R, 7R) -3-carbamoyloxymethyl-7- [2-phenoxyimino-2- phe-nylacetamido] -ceph-3-em-4-carboxylic acid as the syn isomer wins. 16. The method according to claim 1, characterized in that one starts from a compound of formula V, wherein R1 is thien-2-yl and R2 is tert-butyl, and the (6R, 7R) -3-carbamoyloxymethyl-7- [2-tert-butoxyimino-2- (thien-2-yl) acetamido] -ceph-3-em-4-carboxylic acid as the syn isomer wins. 17. The method according to claim 1, characterized in that one starts from a compound of formula V, wherein R1 is thien-2-yl and R2 is methyl, and the resulting (6R, 7R) -3-carbamoyloxymethyl-7- [2-methoxyimino-2- (thien-2-yl) acetamido] -ceph-3-em-4-carboxylic acid as the syn isomer. 18. The method according to claim 1, characterized in that one obtained a compound of formula I, wherein B> S- »0 means to a corresponding connection, where B> S means reduced. 19. Use of 7-acylaminoceph-3-em-4-carboxylic acids l »of the formula I prepared by the process according to claim 1 for the preparation of their non-toxic esters, characterized in that the former are reacted with an esterifying agent.