Process for the preparation of syn-aminothiazolyl and syn-amino-oxazolyl derivatives of alkoxyiminoacetic acids

摘要

A process has been developed for the preparation of compounds of the general formula: IMAGE where R stands for hydrogen or a lower alkyl, acetyl, beta , beta , beta -trichloroethylcarbonyl, choroacetyl or trityl radical, R1 denotes a lower alkyl radical, R2 denotes hydrogen or a lower alkyl radical and X stands for sulphur or oxygen; as the organic phase, where the alkylation takes place, halogenated hydrocarbons, esters of lower fatty acids, benzene etc. are employed. The aqueous phase, which is mixed with the organic phase, is a 10-50% strength aqueous solution of an inorganic base. The syn-aminothiazolyl and syn-aminooxazolyl derivatives of the alkoxyiminoacetic acids obtained are used as intermediates for the preparation of lactam antibiotics.