Tetrazolium chloride salts prodn. from formazan - by oxidn. with chlorine in polar solvent, useful as biological stain etc.

摘要

Tetrzolium cpds. of formulae (I) and (II): (where R1 and R2 are H, OH, NO2, Cl or OCH2COOH, and n is 0 or 3) are prepd. by oxidising the corresp. formazan (III) in a polar organic solvent at -5 to +20 degrees C by passing 1-10 moles gaseous Cl2 per mole (III) into the soln. Pref. the solvent is water miscible, specifically absolute ethanol, and reaction is in presence of 1 equiv., on (III)s of NaOH. (I) and (II) are used in biological and agricultural chemistry to examine dehydrogenase-type redox metabolic processes in plants, blood cells, bacteria etc.; to estimate quality and germination of seeds; to assay boron hydride in air, and for histochemical investigation of maize. Better yields and shorter reaction times are achieved. compared with use of other oxidising agents e.g. 80% in 10-60 min c.f. 32% in =10 hr. Purity is is not 96%.