oxythiamine

noun

oxy·​thi·​a·​mine -ˈthī-ə-mən  -ˌmēn 

variants also oxythiamin

-mən 

: a chemical compound C₁₂H₁₆ClN₃O₂S that differs from thiamine in having the amino group in the pyrimidine ring replaced by a hydroxyl group and that is a thiamine antagonist producing symptoms of thiamine deficiency