Crystal Structures of 2-Phenyl-2H-1,2,3-Triazol-4-Carbaldehyde, an Active a-Glycosidase Inhibition Agent, and (1-Phenyl-1H-1,2,3-Triazol-4-yl)Methyl Benzoate and (2-(4-Fluorophenyl)-2H-1,2,3-Triazole-4-yl)Methanol, Two Moderately Active Compounds

The crystal structures of (1-phenyl-1H-1,2,3-triazol-4-yl)methyl benzoate, 1a, (2-(4-fluorophenyl)-2H-1,2,3-triazole-4-yl)methanol, 2a, and 2-phenyl-2H-1,2,3-triazol-4-carbaldehyde, 2b, are reported. Compounds 1a and 2a were recently reported to exhibit mild α-glycosidase inhibition activity, while compound 2b exhibited a much greater activity. Only small dihedral angles 6.52(4), 14.02(10) and 2.44(7)° are present between the triazolyl ring and the attached aryl rings in 1a, 2a and 2b, respectively. The relatively flat compounds 2a and 2b contrast with compound 1a, which is “V” shaped, with a dihedral angle between the near planar phenyltriazolyl-CH2 and phenyl-CO2CH2 moieties of 88.11(4)°. The intermolecular interactions in 1a are C–H···X (X = N or π(triazole) and π(triazole) ···π(phenyl): two different chains are formed, from (i) combinations of the C–H···N hydrogen bonds and (ii) combinations of the C–H···π and π···π interactions.. The intermolecular interactions in 2a are C–H···O and C–F···π(phenyl): the C–H···O interactions generate a sheet of molecules, containing a network of rings.·Classical O–H···O hydrogen bonds, and weaker C–H···π(triazolyl) and π(phenyl)···π(triazolyl) interactions are present in 2b: all three interactions together generate a chevron-type arrangement. Compound 1a crystallizes in the monoclinic space group P21 with a = 4.5661(5), b = 10.5573(14), c = 13.9694(19) Å, β = 90.594(6)° and Z = 2. Compound 2a crystallizes in the monoclinic space group P21 with a = 3.7175(7), b = 10.428(2), c = 10.689(3) Å, β = 90.521(6)° and Z = 2. Compound 2b crystallizes in the monoclinic space group P21/c with a = 11.4130(5), b = 4.80280(10), c = 15.5916(11) Å, β = 103.373(7)° and Z = 4.