Potassium Carbonate → Benzoyl chloride

Participants

Reaction Steps

When the requisite 5-O-thioformyl intermediate is prepared by reacting tobramycin with an excess of benzoyl chloroformate and potassium carbonate in aqueous methanol in a manner similar to that described in Preparation 1A(1) followed by reaction of the thereby formed 1,3,2',6',3"-penta-N-benzyloxycarbonyltobramycin with benzoyl chloride in pryidine in the manner of Preparation 1C(1) thence reaction of the resulting 1,3,2',6',3"-penta-N-benzyloxycarbonyl-4',2",4",6"-tetra-O-benzoyltobramycin with N,N-dimethyl-α-chloroformimidinium chloride in methylene chloride in pyridine followed by treatment with dry hydrogen sulfide in a manner similar to that described in Preparation 1D(1) whereby is obtained 1,3,2',6',3"-penta-N-benzloxycarbonyl-5-O-thioformyl-4',2",4",6"-tetra-O-benzoyltobramycin.

Provenance & Evidence