An Efficient Method for Removal of Residual Palladium from Organic Solution of Faropenem Sodium in the Pd(II)-Catalyzed Cleavage of Allyl Faropenem

An improved palladium(II)-catalyzed cleavage of the allyl group in allyl faropenem 2 into faropenem sodium 1 is described. The development of an efficient method for the removal of palladium impurities from the crude product 1 upon treatment with polystyrene-bound 2,4,6-trimercapto-s-triazine (polystyrene-bound TMT) led to a drastic decrease of residual palladium level from 1500-1600 ppm to less than 10 ppm in the final isolated product. The palladium(II)-catalyzed cleavage and palladium removal process demonstrated on 10 kg scale are highly convenient and efficient.