Abstract
By benzoylation of thiamine-disulfide (I), at least two products were obtained : Tetrabenzoate of (I), mp. 97-100℃ by the excess amount of benzoyl chloride and dibenzoate of (I), mp. 146-147℃ by the limited use of benzoyl chloride both in a pyridine or alkaline solution of (I), were isolated. Tetrabenzoate is sparingly soluble in acidic water and its structure is designated as (II) from its analytical value and infrared-spectrum. Beside dibenzoate (benzoylthiamine-disulfide) (III), a crystalline mixture of an unsharp mp. of 117-138℃ was obtained, when the reaction was carried out under ice-cooling. It contains two products, as its paper partition chromatogram indicated two spots ; Rf 0.57 and 0.74,of which 0.74 coincides with benzoylthiamine-disulfide.
