Structure and Antibacterial Activity of 3-(3,4-Dimethoxyphenyl)furan-2(5H)-ones

Abstract

Crystalline hydrate of the title compound (5), C19H26N2O5·2(H2O), was structurally characterized by single crystal X-ray diffraction. It crystallizes in monoclinic system space group P 21/c with a = 7.3987(7) A, b = 17.8691(16) A, c = 17.0022(13) A, β = 112.944(3)°, V = 2070.0(3) A3, Z = 4, R 1 = 0.0592, wR 2 = 0.1016, and T = 298(2) K. The X-ray structure determination revealed that the center furanone ring is nearly coplanar with 3,4-dimethoxybenzene ring, making a dihedral angle of 0.860(69)°. Two kinds of centrosymmetric tetramers characterized by graph-set motifs of R 7 8 (36) and R 4 6 (32) are formed through O–H···O, O–H···N and C–H···O hydrogen bonding interactions, which generate a sheet of edge-fused rings parallel to the (011) plane. These sheets are further linked into a three dimensional network by C–H···π interactions. Nine 3-(3,4-dimethoxyphenyl)furan-2(5H)-ones were synthesized and fully characterized by elemental analysis, MS and 1H NMR. All of them were evaluated for antimicrobial activities against three Gram-positive organisms and a Gram-negative organism, and compound 5 was the most active against Staphylococcus aureus ATCC 25923. Two kinds of centrosymmetric tetramers characterized by graph-set motifs of R 7 8 (36) and R 4 6 (32) are formed through O–H···O, O–H···N and C–H···O hydrogen bonding interactions, which generate a sheet of edge-fused rings parallel to the (011) plane.