Studies on the Pyrimidine Derivatives and Related Compounds. XXXIII

Abstract

Reactions were carried out between the sodium salt of thiophenol (IV) with benzoyl (IIIa), p-toluoyl (IIIb), p-nitrobenzoyl (IIIc), acetyl (IIId), dimethylcarbamoyl (IIIe), and diethyl (IIIf) cyanophosphonate. Only S-acylation and S-ethylation were-effected in IIIa to IIId, and only S-ethylation in IIIe and IIIf. At the same time, diphenyl disulfide (VII) was formed from IIIa to IIId. In the case of IIIc, formation of phenyl p-nitrothiobenzoate (Vc) and phenyl ethyl sulfide (VI) was so small as to be barely isolable and VII was the main product.The same reaction between the sodium salt of thiamine (VIII) and IIIa unexpectedly gave some crystals (IX) of m.p. 163-164°, and not the anticipated S-ethylthiamine or O, S-dibenzoylthiamine. The composition of IX agreed with that of dibenzoylthiamine but the compound was apparently different from the result of ultraviolet (Fig. 1), infrared (Fig. 2), and NMR (Fig. 4) spectra. Alkali treatment of IX liberated one mole of benzoic acid. Its fundamental structure is very stable and the compound is different from the known thiamine derivative. It was assumed that the pyrimidine portion in this compound remains intact and the benzoyl group has been introduced into the thiazole portion, with the hydroxyethyl group forming a benzoate, thus creating a new type of thiamine compound.