Abstract
HCl decomposition of S-ethoxycarbonylthiamine (I) gave 2-methy1-4-amino-5-aminomethylpyrimidine (II), formic acid and 3-ethoxycarbonylthio-5-hydroxy-2-pentanone (III). 3-Ethoxycarbonylthio-5-acetoxy-2-pentanone (VIII) was prepared. A part of it Was decomposed into O-ethoxycarbonylthiamine (IV) and thiamine (V). Also O, S-bis (ethoxycarbonyl) thiamine (IX) decomposed into (II), formic acid and 3-ethoxycarbonylthio-5-ethoxycarbonyl-2-pentanone (X) by heating with HCl. A part was also decomposed into (IV) and (V).(X) was characterized by synthesis. Further, ethylthiocarbonylthiamine (XIV) was prepared, and O-alkoxycarbonylthiamine was obtained by rearrangement of S-alkoxycarbonylthiamine. By the use of this rearrangement, various kinds of O, S-bis (alkoxycarbonyl) thiamine were prepared. All of these thiamine derivatives showed excellent thiamine activity in absorption from intestine and in thiamine blood level.
