Purification process

Dicyclohexylammonium salt of 7-amino-3-vinyl-cephalosporanic acid in crystalline form

• Tert.octylammonium salt of 7-amino-3-vinyl-cephalosporanic acid in crystalline form
• N-Benzyl-tert.butylammonium salt of 7-amino-3-vinyl-cephalosporanic acid in crystalline form
• 2-Ethyl-1-hexylammonium salt of 7-amino-3-vinyl-cephalosporanic acid in crystalline form
• Potassium salt of 7-amino-3-vinyl-cephalosporanic acid in crystalline form.

Depletion process of 7-ADCA of formula

• 22
• in mixtures of vinyl-ACA of formula
• 23
• with 7-ADCA, characterised in that
• a) a mixture of vinyl-ACA and 7-ADCA is converted into salts of formula
• 24
• wherein X⊕ is Li⊕, Na⊕, K⊕ or a cation of formula
• 25
• wherein R1′, R2′ and R3′ are the same or different and independently of one another denote hydrogen, (C1-8)alkyl, optionally substituted benzyl or phenyl or (C4-8)cycloalkyl, or R1′ and R2′ together with the nitrogen form a 5- or 6-membered heterocycle which optionally contains a further one or two hetero atoms, and R3′ is as defined above,
• by reaction of the mixture of vinyl-ACA and 7-ADCA with a lithium, sodium or potassium base or with an amine of formula
• 26
• wherein R1′, R2′ and R3′ are as defined above, whereby
• α) the reaction is carried out in a solvent or solvent mixture in which the salts of formulae III and IV have different solubilities, or
• β) the salts of the compounds of formulae III and IV are suspended in a solvent or solvent mixture, and the solubility product is adjusted,
• and after isolating the compound of formula III, this is converted using an acid into the compound of formula I having no content or a reduced content of 7-ADCA, or
• b) a solution of a mixture of vinyl-ACA with 7-ADCA is subjected to chromatography.