Vitamin B₁および諸関係化合物の研究 第102報

Thiamineの新化学反応について (4) Thiamineの強アルカリ域における変化 その1

抄録

Thiol-type thiamine forms a desulfurization-substitution product (II) by reaction with acetamidine but this reaction does not take place with guanidines due to their strong alkalinity and the product formed was a new compound, Substance X, C₁₆H₂₆O₃N₄S, obtained by application of 4 molar equivalents of sodium hydroxide to the thiamine salt (I). Application of 2-3 molar equivalents of sodium hydroxide to (I) produces thiothiamine or diazepine compound (III) and it is interesting that the reaction of (I) differs so markedly by the difference in the quantity of alkali. This chemical reaction was examined in thiazolium compounds other than thiamine and a compound of the same system as Substance X was found to be formed from thiazolium compounds with 2-hydroxyethyl group in 5-position by the action of strong alkali. Substance X is formed almost quantitatively by alkaline reaction of the diazepine compound (III) and 3-mercapto-5-hydroxy-2-pentanone (X).