| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for simply producing, in high yield, the subject derivative whose 2-site is chlorinated, useful as an intermediate or the like for a variety of sialic acid derivatives and medicines by bringing a specific sialic acid derivative in an inert solvent into contact with a hydrogen chloride gas. SOLUTION: This method blows a hydrogen chloride gas into an inert solvent, e.g. toluene or the like, containing a sialic acid derivative shown by formula I [(R<1> is a 2-7C acyl; and R<2> is a 1-6C alkyl or phenylalkyl (where, 1-3C in the case of alkyl)], e.g. 5-acetamide-2,4,7,8,9-pent-O-acetyl-3,5-dideoxy-β-D-glycero- D-galacto-2-nonulopyranosonic benzyl ester and the like, allows the reaction system to be left to stand for 2h, blows a nitrogen gas into the system, and distills off the solvent under a vacuum from the system, to simply produce the objective sialic acid derivative whose 2-site is chlorinated, shown by formula II, in high yield.
|
