抄録
Thiamine-ylide (II) obtained by the treatment of thiamine-HCl (I) with piperidine reacted with diethylbenzoylphosphonate (III) to give 1-phenyl-3-(2-hydroxy) ethyl-4,9-dimethyl-1,6-dihydropyrimido[4', 5'-4,5]pyrimido[2,3-c][1,4] thiazine (IV), IV-benzoate (V), and N-benzoylpiperidine (VI), while the reaction of morpholine treated I with III gave only small amount of IV, but N-benzoylmorpholine (VII), and 4-(2-methyl-4-amino-5-pyrimidyl) methylmorpholine (VIII) as main reaction products. It is interesting that the evidence thus obtained VIII from the above mentioned reaction offers a new progressive demonstration to previous amine substitution reactions to thiamine-thiazole nucleous in the presence of sulfite anion.
