Molecular and crystal structures of N-arylglycopyranosylamines formed by reaction between sulfanilamide and D-ribose, D-arabinose and D-mannose

The X-ray crystal structures of three monosaccharide derivatives prepared by the reaction of sulfanilamide with D-ribose, D-arabinose, and D-mannose have been determined. The derivatives are N-(p-sulfamoylphenyl)-α-D-ribopyranosylamine (1), N-(p-sulfamoylphenyl)-α-D-arabinopyranosylamine (2), and N-(p-sulfamoylphenyl)-β-D-mannopyranosylamine monohydrate (3). The monosaccharide ring of 1 and 2 has the ¹C₄ conformation, stabilized in 1 by an intramolecular hydrogen bond from O-2 to O-4. Compound 3 has the ⁴C₁ conformation at the monosaccharide ring and the gt conformation at the C-6-O-6 side chain. Occupancy of the water molecule in the crystal of 3 actually examined was 22%. The degree of interaction between sulfamoyl groups and monosaccharide moieties varies from structure to structure. The packing arrangement of 2 involves hydrogen bonding between sulfamoyl groups and monosaccharide hydroxyl groups, but interactions of this type are fewer in 1, and in 3 the hydrogen bonds are either strictly between monosaccharide hydroxyl groups or strictly between sulfamoyl groups. Pairs of hydrogen bonds (two-point contacts) link neighboring molecules in all three structures, between screw-axially related molecules in 1 and 2 and between translationally related molecules in 3. The contact in 3 defined by the O-3-H...O-5 and O-6-H...O-4 hydrogen bonds is found in several other N-aryl-β-D-mannopyranosylamine crystal structures and is apparently an especially favorable mode of intermolecular interaction in these compounds.