m-Chloroperbenzoic acid → Methyl acetate hexane

Beteiligte Stoffe

Reaktionsschritte

10.35 g (51.1 mmols) of m-chloroperbenzoic acid (85% strength) are added to a solution of 20.7 g (33.8 mmols) of a mixture consisting of 7β-phenoxyacetylamino-3-(1-methyl-5-tetrazolylthio)-3-cephem-4-carboxylic acid diphenylmethyl ester and 7β-phenoxyacetylamino-3-(1-methyl-5-tetrazolylthio)-2-cephem-4-carboxylic acid diphenylmethyl ester in 350 ml of chloroform at 0° C. and the mixture is stirred for 2 hours. Excess per acid is then destroyed by adding 85 ml of 0.1 N sodium thiosulphate. The reaction solution is extracted with aqueous sodium bicarbonate solution and saturated aqueous sodium chloride solution and the organic phase is dried over sodium sulphate and concentrated in vacuo. The residue is dried in a high vacuum and gives a mixture of the 1β-oxide and 1α-oxide of 7β-phenoxyacetylamino-3-(1-methyl-5-tetrazolylthio)-3-cephem-4-carboxylic acid diphenylmethyl ester; thin layer chromatogram: silica gel (toluene/ethyl acetate, 1:2), β-sulphoxide: Rf=0.26; α -sulphoxide: Rf=0.13. The two sulphoxides are chromatographed on 1 kg of silica gel with toluene/ethyl acetate, 1:2, and the pure β-sulphoxide of melting point 146° C. (from methyl acetate/hexane; IR spectrum (nujol): characteristic bands at 3.05; 5.58; 5.78; 5.83 and 5.97μ), and the pure α-sulphoxide of melting point 180° C. (decomposition; from methylene chloride/diethyl ether; IR spectrum (nujol): characteristic bands at 2.95; 5.53; 5.77 and 5.92μ) are obtained.

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