7-iodo-8-aza-7-deaza-2 `-deoxyadenosine and 7-bromo-8-aza-7-deaza-2 `-deoxyadenosine

Abstract

The isomorphous structures of the title molecules, 4-amino-1-(2-deoxy-beta-D-erythro-pentofuranosyl)-3-iodo-1H-pyrazolo-[ 3,4-d]pyrimidine, (I), C10H12IN5O3, and 4-amino-3-bromo-1-(2-deoxy-beta-D-erythro-pentofuranosyl)-1H-pyrazolo[ 3,4-d]pyrimidine, (II), C10H12BrN5O3, have been determined. The sugar puckering of both compounds is C1'-endo (E-1'). The N-glycosidic bond torsion angle chi(1) is in the high-anti range [-73.2(4)degrees for (I) and -74.1 (4)degrees for (II)] and the crystal structure is stabilized by hydrogen bonds.