Application of Chromatography. XXXVII. Total Synthesis of 6, 7-Dimethylribolumazine.

Abstract

Attempt was made for the total synthesis of 6, 7-dimethylribolumazine which is considered to be an intermediate in the biosynthesis of riboflavin. In the first place, crude 4-ribitylaminouracil was prepared from 4-chlorouracil and D-ribamine. Although this compound could not be produced in a pure enough state, it was isolated as its 5-nitroso derivative as pretty rods, m.p. 105°(decomp.). This nitroso compound was reduced to the corresponding amino compound with sodium hydrosulfite, but as the latter could not be separated pure, it was immediately led to 6, 7-dimethylribolumazine by reaction with diacetyl. Physical properties of the product were in complete agreement with those of the 6, 7-dimethylribolumazine separated from the mycelium of Er. ashbyii, and the structure of the product was thereby positively established.