Abstract
In an aqueous solution, sulpyrine caused significant increase in the rate of destruction of thiamine in a pH range of 3-7. This reaction was shown to proceed at an increasing rate with decreasing of acidity, though the effect of pH diminished as the pH passes 5. Activation energy for this reaction has been measured to be 27 kcal/mole and the salt effect was neglegible. Isolation of the decomposition products and the other experimental evidence showed that bisulfite from sulpyrine caused the replacement reaction of thiamine with the basic moiety of sulpyrine and that the rate of this reaction was dependent of bisulfite concentraton. The replacement reaction product, 4-N-methyl-N-[2-methyl-4-aminopyrimidyl-(5)] aminoantipyrine, was compared with sulpyrine in regards to the acute toxicity, the analgesic and the hypothermal activities.
