Abstract
In the course of studies on modified thiamine derivatives, Takamizawa et al. in 1961,synthesized new compounds, S-carbalkoxythiamines. Of the homologues, the physical and chemical properties of the following compounds were studied : S-carbethoxythiamine-HCl (CET), S-carbobutoxythiamine-HCl (CBT), O, S-dicarbethoxythiamine-HCl-H_2O (DCET). These compounds are colorless, odorless and nonhygroscopic. Each is soluble in water and methanol, but not in ether and benzene. The ultraviolet spectra shows these derivatives to have the same λ_<max> at 244 mμ in acidic solution, which varies with the change of pH. The infrared spectra shows specific absorption bands at 1710-1720cm^<-1> (ν_<c=o>) and 1150-1155cm^<-1> (ν_<c=o>), arising from -S・COO- group. DCET, moreover, has strong absorptions at 1750cm^<-1> (ν_<c=o>), 1260cm^<-1> (ν_<c-o>) and 1010cm^<-1> (ν_<c-o>). It was found that DCET is the most stable of the three derivatives, both in aqueous solution or in powder mixture.
