反应详情

Referring to PCT Publication No. WO00/75154, the non-hydrated N4-benzoyl-5′-O-(4, 4′-dimethoxytrityl)-2′-deoxycytidine (2.00 g), including N4-benzoyl-2′-deoxycytidine, N4-benzoyl-3′-O-(4, 4′-dimethoxytrityl)-2′-deoxycytidine, and N4-benzoyl-3′, 5′-O-bis(4, 4′-dimethoxytrityl)-2′-deoxycytidine with rates by peak areas of 1.0%, 0.15%, and 2.2%, respectively, was dissolved in acetonitrile (2.3 mL). The solution was added dropwise to water (41 mL) with vigorous stirring and the resultant mixture was stirred for one hour. A white precipitate was recovered by filtration, was washed twice with water and was dried at 50° C. in a vacuum to yield N4-benzoyl-5′-O-(4, 4′-dimethoxytrityl)-2′-deoxycytidine (1.82 g). The XRD pattern and the DSC thermogram showed neither an absorption peak nor an endothermic peak due to the crystallization, which indicates the resultant components was not crystallized. Moreover, the component contained N4-benzoyl-2′-deoxycytidine, N4-benzoyl-3′-O-(4, 4′-dimethoxytrityl)-2′-deoxycytidine, and N4-benzoyl-3′, 5′-O-bis(4, 4′-dimethoxytrityl)-2′-deoxycytidine and the respective peak areas were 0.9%, 0.13%, and 1.8%, respectively, which indicates that the above procedure had no substantial effect on the purification.

1. filtrationA white precipitate was recovered by filtration
2. washwas washed twice with water
3. customwas dried at 50° C. in a vacuum