A mixture of 0.1029 g ((0.000163 mole) of diphenylmethyl 7-phenylacetamido-3-(trifluoromethylsulfonyloxy)-3-cephem- -4-carboxylate, 0.0775 g (0.000195 mole) of (p-methoxyphenyl)tri-n-butylstannane, 0.044 g (0.00032 mole) of zinc chloride and 0.00378 g (0.000016 mole) of tri(2-furyl)-phosphine in 4 mL of dry 1-methyl-2-pyrrolidinone, under an argon atmosphere, was degassed for 30 seconds. Then 0.0047 g (0.000008 mole) of palladium(0) bis(dibenzylidene acetone) was added all at once. The reaction mix was stirred at 50° for 5.5 hrs and room temperature for 16 hrs. The reaction mix was then diluted with ethyl acetate and the organic solution washed with dilute ammonium chloride. The ethyl acetate was removed at reduced pressure and replaced with acetonitrile. The organic phase was washed with n-pentane and the acetonitrile removed at reduced pressure. The residue was chromatographed on silica gel to yield 0.0548 g (57%) of diphenylmethyl 7-phenylacetamido-3-(p-methoxyphenyl)-3cephem-4-carboxylate. The nuclear magnetic resonance spectrum was consistent for the desired structure.
