Process for preparing enamine derivatives, compounds so produced and process for preparing a 3-hydroxy-cephalosporin
申请人:Lilly Industries Limited
公开号:EP0019401A1
公开(公告)日:1980-11-26
There is described a process for preparing an enamine of formula (IX):
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) :
with an amine of formula HNR5R6, 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.