group such as trimethylsilyl or benzyl,to obtain the imidochloride of the formula (II)FORMULA/TABLE/GRAPHICThen treating the compound of formula (II) with the o-amino thiophenol of the formula (III)FORMULA/TABLE/GRAPHICto yield the benzothiazole of the formula (IV)FORMULA/TABLE/GRAPHICand the 7beta-aminocephalosporine of the formula (v)FORMULA/TABLE/GRAPHICand subsequently the free 4-carboxy ceph