A protected 2′-deoxycytidine is purified by precipitating the protected 2′-deoxycytidine represented by general formula (3) in the form of a hydrated crystal from a solution containing the protected 2′-deoxycytidine and water, and by recovering the protected 2′-deoxycytidine:
wherein R1 represents a 4-methoxytrityl, 4, 4′-dimethoxytrityl, or triphenylmethyl group; and B1 represents a cytosine group having a protected amino group. The compound represented by general formula (3) is, in particular, a protected 2′-deoxycytidine represented by formula (4):
The 2′-deoxycytidine is used as a raw material for antisense DNA.
通过从含有保护的2'-脱氧
胞苷和
水的溶液中沉淀以
水合晶体形式存在的通式(3)所代表的保护的2'-脱氧
胞苷,以及回收保护的2'-脱氧
胞苷,来纯化保护的2'-脱氧
胞苷。其中,R1代表4-甲氧三苯甲基、4,4'-二甲氧三苯甲基或三苯基甲基基团;B1代表具有保护
氨基的
胞嘧啶基团。特别是,通式(3)所代表的化合物是由式(4)所代表的保护的2'-脱氧
胞苷。
2'-脱氧
胞苷用作反义DNA的原材料。