Derek M Walker

US Patent:

56607113, Aug 26, 1997

Filed:

Dec 8, 1995

Appl. No.:

8/569631

Inventors:

Derek Walker - Summit NJ
Junning Lee - Gillette NJ
Charles R. Martin - Fort Collins CO
Haiyan Zhang - Woodbury MN
Loris Sogli - Novara, IT
Ermanno Bernasconi - Caronno Varesino, IT
Vinod Parakkal Menon - Fort Collins CO

Assignee:

Schering Corporation - Kenilworth NJ

International Classification:

C25B 300

US Classification:

205425

Abstract:

A process is described for preparing 3-exomethylene cephalosporanic acid derivatives for use in the synthesis of cephalosporin antibiotics such as ceftibuten. The process comprises electrochemical reduction of a compound of the formula (IV) ##STR1## wherein: R. sup. 3 is CH. sub. 3 C(O)--; ##STR2## is an optional sulfoxide group; n is 2 or 3; R. sup. 1 is H and R is H or NHR. sup. 2, where R. sup. 2 is H or a protecting group selected from C. sub. 6 H. sub. 5 CH. sub. 2 OC(O)--, C. sub. 6 H. sub. 5 C(O)-- or C. sub. 1 -C. sub. 6 alkoxy-C(O)--; or wherein R and R. sup. 1 together with the carbon atom to which they are attached comprise --C(O)--, and produces the desired 3-exomethylene compounds with low levels of the corresponding 3-methyl tautomers.

US Patent:

55719104, Nov 5, 1996

Filed:

May 26, 1995

Appl. No.:

8/451287

Inventors:

Derek Walker - Summit NJ
Junning Lee - Gillette NJ
Charles R. Martin - Fort Collins CO
Haiyan Zhang - Fort Collins CO
Loris Sogli - Novara, IT
Ermanno Bernasconi - Caronno Varesino, IT

Assignee:

Schering Corporation - Kenilworth NJ

International Classification:

C07D50122

US Classification:

540230

Abstract:

A process is described for preparing 3-exomethylene cephalosporanic acid derivatives for use in the synthesis of cephalosporin antibiotics such as ceftibuten. The process comprises electrochemical reduction of a compound of the formula (IV) ##STR1## wherein: R. sup. 3 is CH. sub. 3 C(O)--; ##STR2## is an optional sulfoxide group; n is 2 or 3; R. sup. 1 is H and R is H or NHR. sup. 2, where R. sup. 2 is H or a protecting group selected from C. sub. 6 H. sub. 5 CH. sub. 2 OC(O)--, C. sub. 6 H. sub. 5 C(O)-- or C. sub. 1 -C. sub. 6 alkoxy--C(O)--; or wherein R and R. sup. 1 together with the carbon atom to which they are attached comprise --C(O)--, and produces the desired 3-exomethylene compounds with low levels of the corresponding 3-methyl tautomers.

US Patent:

58471162, Dec 8, 1998

Filed:

Dec 13, 1996

Appl. No.:

8/767268

Inventors:

Derek Walker - Summit NJ
Junning Lee - Gillette NJ
Charles R. Martin - Fort Collins CO
Haiyan Zhang - Woodbury MN
Loris Sogli - Novara, IT
Ermanno Bernasconi - Caronno Varesino, IT
Vinod Parakkal Menon - Fort Collins CO

Assignee:

Schering Corporation - Kenilworth NJ
Antibioticos - Milan

International Classification:

C07D50100

US Classification:

540215

Abstract:

A process is described for preparing 3-exomethylene cephalosporanic acid derivatives for use in the synthesis of cephalosporin antibiotics such as ceftibuten. The process comprises electrochemical reduction of a compound of the formula (IV) ##STR1## wherein: R. sup. 3 is ##STR2## is an optional sulfoxide group; n is 2 or 3; R. sup. 1 is H and R is H or NHR. sup. 2, where R. sup. 2 is H or a protecting group selected from C. sub. 6 H. sub. 5 CH. sub. 2 OC(O)--, C. sub. 6 H. sub. 5 C(O)-- or C. sub. 1 -C. sub. 6 alkoxy-C(O)--; or wherein R and R. sup. 1 together with the carbon atom to which they are attached comprise --C(O)--, and produces the desired 3-exomethylene compounds with low levels of the corresponding 3-methyl tautomers.