Process for production of 3-alkenylcephem compounds

1. A process for preparing 7-amino-3-[(E/Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (1) or an alkali metal salt thereof, said acid or said salt being higher in the weight % content of 7-amino-3-[(Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (2) or of an alkali metal salt thereof than the weight % content of a starting salt, the process comprising: providing an aqueous solution of an alkali metal salt of 7-amino-3-[(E/Z)-2-(4-methylthiazol-5-yl) vinyl]-3-cephem-4-carboxylic acid of the formula (1), treating said aqueous solution with active carbon as added thereto, and, optionally, adding an acid to said treated aqueous solution to convert the salt into an acid

2. A preparation process according to claim 1 wherein the treatment with the active carbon is conducted with stirring.

3. A process for preparing 7-amino-3-[(E/Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (1) and an alkali metal salt thereof, said acid or said salt being higher in the weight % content of 7-amino-3-[(Z)-2-(4-methylthiazol-5-yl) vinyl]-3-cephem-4-carboxylic acid of the formula (2) or of an alkali metal salt thereof than the weight % content of a starting salt, the process comprising: subjecting 7-substituted acylamino-3-[(E/Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid compound of the formula (3) to a deprotecting reaction for the carboxylic acid protective group at the 4-position of said compound, treating the resulting compound with an aqueous solution of at least one compound selected from among alkali metal hydroxides, alkali metal hydrogencarbonates and alkali metal carbonates to obtain an alkali metal salt of 7-substituted acylamino-3-[(E/Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (4), thereafter subjecting the resulting salt to an enzyme reaction in an aqueous solution to obtain an aqueous solution of an alkali metal salt of 7-amino-3-[(E/Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (1) and treating said aqueous solution with active carbon as added thereto, and, optionally, adding an acid to said treated aqueous solution to convert the salt into an acid

wherein R 1 is benzyl or phenoxymethyl, and R 2 is carboxylic acid protective group

wherein R 1 is as defined above, and M is an alkali metal.

4. A preparation process according to claim 3 wherein the treatment with the active carbon is conducted with stirring.

5. A preparation process according to claim 1 wherein the product resulting from the treatment is at least 99% in the contents of 7-amino-3-[(Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (2) and an alkali metal salt thereof.

6. A preparation process according to claim 5 wherein the product resulting from the treatment is at least 99.5% in the contents of 7-amino-3-[(Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (2)and an alkali metal salt thereof.

7. A preparation process according to claim 3 wherein the enzyme reaction is conducted with use of a penicillin G acylase at a reaction temperature of 10 to 50° C. and pH of 7.0 to 9.5.

8. A preparation process according to claim 3 wherein the product resulting from the treatment is at least 99% in the contents of 7-amino-3-[(Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (2) and an alkali metal salt thereof.

9. A preparation process according to claim 8 wherein the product resulting from the treatment is at least 99.5% in the contents of 7-amino-3-[(Z)-2-(4-methylthiazol-5-yl )vinyl]-3-cephem-4-carboxylic acid of the formula (2) and an alkali metal salt thereof.