DINUCLEOTIDE CRYSTALS

摘要

Crystals of P1-(2'-deoxycytidine 5'-) P4-(uridine 5'-) tetraphosphate (dCP4U ) or salts thereof; a process for the production of the crystals; and a proces s for the preparation of dCP4U by reacting uridine 5'-monophosphate (UMP) with 2'-deoxycytidine 5'-monophosphate (dCMP), diphenylphosphoro-chloridate (DPC) and a pyrophospate (PPi). The crystals of dCP4U have a high purity and are easily handleable by virtue of their lower hygroscopicity and higher stabili ty than those of the products of freeze drying, thus being useful as the raw material of drugs. The process for the preparation of dCP4U permits the production of dCP4U by the use of inexpensive UMP as the starting material i n a high yield, thus being suitable for mass production of dCP4U.