The 7-bromo derivative of 2-amino-2'-deoxytubercidin fluorinated at the sugar moiety.

The title compound, 2,4-diamino-5-bromo-7-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-7H-pyrrolo[2,3-d]pyrimidine, C(11)H(13)BrFN(5)O(3), shows two conformations of the exocyclic C4'-C5' bond, with the torsion angle gamma (O5'-C5'-C4'-C3') being 170.1 (3) degrees for conformer 1 (occupancy 0.69) and 60.7 (7) degrees for conformer 2 (occupancy 0.31). The N-glycosylic bond exhibits an anti conformation, with chi = -114.8 (4) degrees . The sugar pucker is N-type (C3'-endo; (3)T(4)), with P = 23.3 (4) degrees and tau(m) = 36.5 (2) degrees . The compound forms a three-dimensional network that is stabilized by several intermolecular hydrogen bonds (N-H...O, O-H...N and N-H...Br).