Benzylpenicillin benzyl ester

Oxidation of phenyl hexyl sulphide with sodium metaperiodate gave also only a trace amount of the corresponding sulphoxide72. On the other hand, Hall and coworkers73 prepared benzylpenicillin and phenoxymethyl penicillin sulphoxides from the corresponding benzyl esters by oxidation with sodium metaperiodate in dioxane solution with a phosphate buffer. A general procedure for the synthesis of penicillin sulphoxides was reported later by Essery and coworkers74 which consists in the direct oxidation of penicillins or their salts with sodium metaperiodate in aqueous solution at pH 6.5-7.0. 1-Butadienyl phenyl sulphoxide 4475 and a-phosphoryl sulphoxides 4576 were also prepared by the same procedure. 

Benzylpenicillinic Acid. 3,3>Dimerhyf-7-oxo-6-[tphenylacetyllamino]-4-th ia-l-azabicyclo 3.2.0]heptane-2-carboxylic acid free benzyl penicillin free penicillin G free penicillin II. C,jHI8Nj04S mol wt 334.38, C 57.47%, H 5.43%, N 8.38%, O 19.14%, S9,59%. Obtained by extraction at ice temp of the acidified (pH 2) aq soln of sodium benzyl -penicillin with ether Or chloroform. Shows correct analytical composition only it moisture is excluded completely during iis isoln from the ether extract (by lyophilizing from benzene). When kept dry the acid retains its antibiotic potency for limited periods, bui it is rapidly inactivated by small amounts of water. The product formed on slow inactivation by moisture seems to be benzylpenicilloic acid, cf. Clarke et [., The Chemistry of Penicillin (Princeton, 1949). Prepn of methyl ester Dan. pet. 85,976 (1958 to Leo Pharm.). Pharmacokinetics in humans M. Barza, L. Weinstein, Clin. 

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