15736-96-6Relevant articles and documents
Preparation of 3-substituted cephalosporins
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, (2008/06/13)
There is described a process for preparing an enamine of formula (IX): STR1 where R2 is a carboxylic acid protecting group and R3 is the residue of a carboxylic acid derived acyl group and where R5 and R6 are the same or different C1-4 alkyl or C7-10 aralkyl groups; or taken together with the adjacent nitrogen atom form a heterocyclic ring containing from 4 to 8 carbon atoms and optionally a further heteroatom selected from oxygen and nitrogen; by reacting a compound of formula (XII): STR2 with an amine of formula HNR5 R6, the reactant of formula (XII) being prepared by reaction of an appropriate enol derivative with a phosphorus reagent. The enamines of formula (IX) are useful in the preparation of 3-hydroxycephalosporins.
