Purine Analogues as Amplifiers of Phleomycin. VI. The Synthesis and Metabolism of Some Benzothiazole, Benzoxazole and s-Triazolopyrimidine Amplifiers

Abstract

The metabolisms of four ¹⁴C-tagged amplifiers of phleomycin are followed in mice. 2-(Benzothiazol- 2'-ylthio)acetamide (1c) gives mainly the corresponding acid (1e) in the urine; 2-(benzoxazol-2'- ylthio)acetamide (1d) likewise gives the acid (1f); N-methyl-2-(s-triazolo[4,3-a]pyrimidin- 3'-ylthio)propionamide (2b) gives unchanged material (c. 20%) plus not the corresponding acid (2c), but its [1,5-a] isomer (3c) in 60% yield; and 2-(5',7'-diethyl-s-triazolo[4,3- a]pyrimidin-3'-ylthio)-acetamide (2i) proves much more stable by giving mainly unchanged material (>60%). Minor metabolites are formed in each case.    

Syntheses and N.M.R. spectra of the above substrates and related derivatives are reported as well as their activities as amplifiers of phleomycin against in vitro cultures of Escherichia coli.