A 2 `-deoxycytidine long-linker click adduct forming two conformers in the asymmetric unit

Abstract

The title compound {systematic name: 4-amino-1-(2-deoxy-beta-d-erythro-pentofuranosyl)-5-[6-(1-benzyl-1H-1, 2,3-triazol-4-yl)hex-1-ynyl]pyrimidin-2(1H)-one}, C24H28N6O4, shows two conformations in the crystalline state, viz. (I-1) and (I-2). The pyrimidine groups and side chains of the two conformers are almost superimposable, while the greatest differences between them are observed for the sugar groups. The N-glycosylic bonds of both conformers adopt similar anti conformations, with chi= -168.02 (12)degrees for conformer (I-1) and chi = -159.08 (12)degrees for conformer (I-2). The sugar residue of (I-1) shows an N-type (C3'-endo) conformation, with P = 33.1 (2)degrees and tau m = 29.5 (1)degrees, while the conformation of the 2'-deoxyribofuranosyl group of (I-2) is S-type (C3'-exo), with P similar to= 204.5 (2)degrees and tm = 33.8 (1)degrees. Both conformers participate in hydrogen-bond formation and exhibit identical patterns resulting in three-dimensional networks. Intermolecular hydrogen bonds are formed with neighbouring molecules of different and identical conformations (NH...N, NH... O, OH...N and OH...O).