3-Allyl, benzyl or heterocyclyl:methyl 3-cephem prepn. - by coupling 3-halomethyl 3-cephem with hydrocarbyl tri:alkyl stannane in polar aprotic solvent in presence of palladium cpd. and phosphine

摘要

Process is claimed for producing a cephalosporin cpd. having the ceph-3-em nucleus bearing known cephalosporin antibiotic substits. at the 4-, 7- and 8- positions and a -CH2R1 substit. at the 3-position. R= (opt. substd.) vinyl, (opt. substd.) phenyl, 2-, 3- or 4- pyridyl, imidazolyl, 2- thiazolyl, 2- or 3- furyl or 2- thienyl; where the opt. substits. on vinyl and phenyl are chosen from 1-4C alkyl, 1-4C alkoxy, F, Cl, Br and I. The process comprises contacting in a polar aprotic solvent a 3- halomethyl ceph-3-em having substits. at the 4-, 7- and 8-positions which are non-reactive under the reaction conditions with the reagents employed; and (a) at least an equimolar amt. of R1-tri(1-4C alkyl) stannane; (b) 1-10 mol.% of a Pd(O) or Pd(II) cpd.; and (c) 3-30 mole.% of tri(2-furyl) phosphine or tri(2-thienyl) phosphine. Reaction is at 20-75 deg.C for 1-72 hrs.