Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D499/00—Heterocyclic compounds containing 4-thia-1-azabicyclo [3.2.0] heptane ring systems, i.e. compounds containing a ring system of the formula:, e.g. penicillins, penems; Such ring systems being further condensed, e.g. 2,3-condensed with an oxygen-, nitrogen- or sulfur-containing hetero ring
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D501/00—Heterocyclic compounds containing 5-thia-1-azabicyclo [4.2.0] octane ring systems, i.e. compounds containing a ring system of the formula:, e.g. cephalosporins; Such ring systems being further condensed, e.g. 2,3-condensed with an oxygen-, nitrogen- or sulfur-containing hetero ring
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
  • C12P35/00—Preparation of compounds having a 5-thia-1-azabicyclo [4.2.0] octane ring system, e.g. cephalosporin

Definitions

• the invention relates to a process for the recovery of a ⁇ -lactam antibiotic from a mixture containing the ammonium salt of the corresponding ⁇ -lactam core and the ammonium salt of the ⁇ -lactam antibiotic.
• the process for preparation of a ⁇ -lactam antibiotic involving the acylation of a corresponding ⁇ - lactam core by means of a suitable acylation agent, the recovery of the ⁇ -lactam antibiotic and the working up of the reaction mixture are difficult in general.
• the reaction mixture often still contains valuable components, such as for instance the ⁇ - lactam core. In order to get a commercially attractive process it is therefore necessary to recover in virtually pure form the ⁇ -lactam antibiotic formed, while at the same time minimizing the losses of ⁇ -lactam core and ⁇ - lactam antibiotic.
• the object of the invention therefore is to provide a process which enables recovery of the ⁇ -lactam antibiotic in sufficiently pure form and working up or recirculating the remaining mixture simply and without significant losses of ⁇ -lactam core and ⁇ -lactam antibiotic.
• This is achieved according to the invention by subjecting the mixture to a physical treatment in which ammonia is released from the ammonium salts that are present and is carried off as such and the precipitate of the ⁇ -lactam antibiotic released is recovered.
• the fact is that it has been found that in the process according to the invention the free ⁇ -lactam antibiotic is precipitated selectively, while the ⁇ -lactam core remains behind in solution. In this way it appeared to be possible to recover the ⁇ -lactam antibiotic with a purity greater than 90% on a dry weight basis, in particular greater than 98%.
• the term 'physical treatment' in the framework of the present invention is opposed to chemical treatment, for instance the chemical reactions in which inorganic ammonium salts are formed by means of a strong acid.
• suitable physical treatments to which the mixture can be subjected are stripping with steam or an inert gas such as described for instance in Perry's Chemical Engineers' Handbook, R.H. Perry, D. Green, 2nd edition (1985), (steam) distillation at reduced pressure, in particular thin-film evaporation, such as described for instance by Mutzenberg et al. in Chem. Eng. 12_, 175-190 (1965), evaporation in a spray tower, such as described for instance by Mehta and Shorma in Br. Chem. Eng.
• the treatment is mostly carried out at a temperature between -5 and 40°C, preferably between 0 and 40°C, more preferably between 0 en 30°C particularly between 5 and 30°C.
• the pH of the mixture to be treated depends on the nature and the concentration of the individual components. In view of the stability of the ⁇ -lactam core and the ⁇ -lactam antibiotic, the treatment is mostly carried out at a pH lower than 8.5, in particular at a pH between 5.5 and 8.5, preferably at a pH between 6 and 8. During the treatment ammonia is removed, so that the pH is lowered. By adjusting the intensity and the duration of the treatment, the pH resulting at the end of the treatment can be varied. The optimum final pH depends on the composition of the mixture and is chosen such that an optimum separation of ⁇ -lactam core and ⁇ -lactam antibiotic is obtained.
• the optimum final pH in practice is a compromise between on the one hand high purity of the recovered antibiotic, which is achieved if the pH is lowered relatively little, so that the ⁇ -lactam antibiotic is still partially and the ⁇ -lactam core still fully in solution, and on the other hand a high yield, which is achieved if the pH is lowered so far that the ⁇ -lactam antibiotic is precipitated virtually completely, but at the same time part of the ⁇ -lactam core is precipitated.
• the process according to the invention is in particular suitable for application to the reaction mixture obtained after an enzymatic acylation reaction in which a ⁇ -lactam antibiotic is prepared by enzymatic acylation of the corresponding ⁇ -lactam core with a suitable acylation agent.
• Suitable examples of ⁇ -lactam cores that can be used in the process according to the invention are penicillic acid derivatives, for instance 6- aminopenicillic acid (6-APA), and cephalosporanic acid derivatives, for instance 7-aminocephalosporanic acid (7- ACA), 7-aminodesacetoxy-cephalosporanic acid (7-ADCA) and 7-amino-3-chlorocephalosporanic (7-ACCA) .
• Suitable acylation agents that can be used in the process according to the invention are for instance ⁇ - amino acid derivatives, in particular amides and esters of phenyl glycine, p-hydroxyphenyl glycine and dihydrophenyl glycine.
• any enzyme can be used that is suitable as catalyst in the coupling reaction.
• Such enzymes are for instance the enzymes that are known under the general designations 'penicillin amidase' and 'penicillin acylase'.
• suitable enzymes are enzymes derived from Acetobacter, Aeromonas. Alcali ⁇ enes, Aphanocladium, Bacillus SP. , Cephalosporium.
• Escherichia Flavobacterium, Kluvvera, Mvcoplana, Protaminobacter, Pseudomonas and Xanthomonas, in particular Acetobacter pasteurianum, Acali ⁇ enes faecalis, Bacillus me ⁇ aterium, Escherichia coli and Xanthomonas citrii.
• an immobilized enzyme is used, since the enzyme can be easily re-used then.
• Immobilized enzymes are known as such and are commercially available. Highly suitable enzymes have appeared to be the Escherichia coli enzyme from Boehringer Mannheim GmbH, which is commercially available under the name 'Enzygel®', the immobilized Penicillin-G acylase from Recordati, the immobilized Penicilline-G acylase from Pharma Biotechnology Hannover, and an Escherichia coli penicilline acylase isolated as described in WO-A-92/12782 and immobilized as described in EP-A-222462.
• the enzymatic acylation reaction is mostly carried out at a temperature between -5 and 35°C, particularly between 5 and 35°C, preferably between 0 and 28°C, particularly between 20 and 28°C.
• the pH at which the acylation reaction is carried out is mostly between 6 and 8.5.
• the optimum pH depends on, among other things, the antibiotic, since the stability and the solubility of the ⁇ -lactam antibiotic as well as the ⁇ -lactam core depend on the pH. If a phenyl glycine derivative is used as acylation agent the pH is preferably between 6.2 and 8.5, particularly between 7 and 8; if a p-hydroxyphenyl glycine derivative is used as acylation agent the pH is preferably between 6 and 7.5, particularly bewteen 6 and 7. Besides, the enzyme activity is also pH-related.
• the acylation reaction is mostly carried out in water.
• the reaction mixture may also contain an organic solvent or a mixture of organic solvents, preferably less than 30 vol.%.
• organic solvents that can be used are alcohols with 1-7 carbon atoms, for instance a monoalcohol, in particular methanol or ethanol; a diol, in particular ethylene glycol or a triol, in particular glycerol.
• the process according to the invention is preferably applied to a mixture that has been obtained by enzymatic acylation of a ⁇ -lactam core by means of an amide as acylation agent, the concentration of inorganic salts in the reaction mixture being lower than 1000:n mM, n representing the valency of the anion.
• a free amide is used as acylation agent and the molar ratio between the acylation agent and the ⁇ -lactam core is chosen between 0.5:1 and 2:1.
• Such a process can be carried out at relatively high concentrations; the sum of the concentrations of the ⁇ -lactam antibiotic and the ⁇ -lactam core is for instance between 200 and 800 mM, preferably between 300 and 700 mM, particularly 300 and 600 mM. It has appeared that under such conditions the pH remains sufficiently low during the acylation reaction, so that the pH need not be controlled through titration during the acylation reaction.
• This preferred process offers the advantage that during the entire process essentially no inorganic salts are formed, so that the reaction mixture obtained after the acylation reaction can as such be returned to the acylation reaction after the physical treatment, in which ammonia is released and carried off, and after separation of the precipitated ⁇ - lactam antibiotic. In such a process therefore essentially no ⁇ -lactam core and ⁇ -lactam antibiotic are lost.
• the pH is generally kept at a constant level by titration with ammonia, so that also a mixture of the ammonium salts of the ⁇ -lactam antibiotic and the ⁇ -lactam core is obtained.
• a free ester is preferably used as acylation agent.
• Such a process can be carried out at relatively high concentrations; the sum of the concentrations of the ⁇ -lactam antibiotic and the ⁇ -lactam core is for instance between 200 and 800 mM, preferably between 300 and 700 mM, particularly between 300 and 600 mM.
• This preferred process offers the advantage that during the entire process essentially no inorganic salts are formed, so that the reaction mixture obtained after the acylation reaction can as such be returned to the acylation reaction after the physical treatment, in which ammonia is released and carried off, and after separation of the precipitated ⁇ -lactam antibiotic. In such a process as well, essentially no ⁇ -lactam core and ⁇ -lactam antibiotic are lost.
• CEX cephalexin
• CEX.H 2 0 cephalexin monohydrate
• 7-ADCA 7-aminodesacetoxy-cephalosporanic acid
• D-PGA D-phenyl glycine amide
• D-PG D-phenyl glycine
• the starting mixture used was a mixture obtained after the enzymatic acylation reaction of 7-ADCA and D-PGA containing 50 mmol (10.7 g) of 7-ADCA, 50 mmol (18.2 g) of CEX.HjO a-nd 25 mmol of D-PGA (3.8 g), 26 mmol of D-PG (3.9 g), 220 ml of water and ammonia (77 mmol), mainly present as ammonium salt of CEX.H 2 0, 7-ADCA and D-PG.
• the pH of the clear solution at 21°C was 7.90. Successively, at a pressure of 1.6 kPa (12 mm Hg), 140 ml were distilled off and 140 ml of water were added.
• the temperature of the heating element was set to 45°C. In this way 3056 g of condensate was collected in 65 minutes (average rate of evaporation: 2820 g/h). In this situation the superficial vapour velocity was approx. 2 m/s. During the evaporation crystallization occurred.
• the slurry was filtered through a glass filter, without any problem.
• the weight of the wet cake was 197.1 g.
• CEX.H 2 0 was obtained.
• This substance consisted of needle-shaped crystals with an average length of 150 ⁇ and an average diameter of 10-15 ⁇ m.
• Example IV 218.6 g (purity: 99%) of CEX.H 2 0, 130.8 g
• CEX.H 2 0 was obtained.
• This substance consisted of needle-shaped crystals with an average length of 150 ⁇ m and an average diameter of 10-15 ⁇ m.

Landscapes

• Organic Chemistry (AREA)
• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Zoology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Microbiology (AREA)
• General Chemical & Material Sciences (AREA)
• Biotechnology (AREA)
• Health & Medical Sciences (AREA)
• Biochemistry (AREA)
• Bioinformatics & Cheminformatics (AREA)
• General Engineering & Computer Science (AREA)
• General Health & Medical Sciences (AREA)
• Genetics & Genomics (AREA)
• Cephalosporin Compounds (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=3888754

Family Applications (1)

Country Status (5)

Cited By (1)

• 1995
  • 1995-02-02 BE BE9500080A patent/BE1009070A3/nl not_active IP Right Cessation
• 1996
  • 1996-02-01 IN IN163MA1996 patent/IN181946B/en unknown
  • 1996-02-01 WO PCT/NL1996/000053 patent/WO1996023797A1/en not_active Application Discontinuation
  • 1996-02-01 EP EP96904338A patent/EP0869962A1/en not_active Withdrawn
  • 1996-02-01 AU AU48463/96A patent/AU4846396A/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events