Process for preparing 7-substituted-amino-3-hydroxy-3-cephem-4-protected carboxy-sulfoxide esters
AssigneeEli Lilly and Company
InventorFrank Brown, Jr.
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Abstract
A process for the conversion of a 4-chlorosulfonyl azetidinone (a) to a 3-hydroxy-3-cephem-sulfoxide ester (d) by subjecting an intermediate comprising a tin containing Lewis acid-type Fiedel-Crafts catalyst and 3-exomethylene cepham to ozonolysis.
Claims18
A process for the preparation of a compound of the formula ##STR36## wherein A is an amino protecting group or a group of the formula ##STR37## wherein R is the residue of a carboxylic acid RCOOH;
- and R.sub.1 is a carboxy-protecting group, comprising the step of reacting an intermediate complex comprising a tin-containing Lewis acid-type Friedel-Crafts catalyst and a compound of the formula (2) ##STR38## with ozone, under substantially anhydrous conditions.
In a process for preparing a compound the formula (1) ##STR46## wherein A is an amino protecting group of the formula ##STR47## wherein R is the residue of a carboxylic acid RCOOH and R.sub.1 is a carboxy protecting group, by reacting a compound of the formula ##STR48## wherein R.sub.5 is ##STR49## or imido, with a tin-containing Lewis acid-type Friedel-Crafts catalyst, said reacting forming an intermediate complex comprising the catalyst and a compound of the formula (2) ##STR50## the improvement characterized in ozonizing the intermediate complex without any substantial prior isolation of the compound of formula (2).
Dependencies are inferred from the claim text.