No abstract

Crystalline hydrate of the title compound (5), C 19 H 26 N 2 O 5 Á2(H 2 O), was structurally characterized by single crystal X-ray diffraction. It crystallizes in monoclinic system space group P 21/c with a = 7.3987(7) Å , b = 17.8691(16) Å , c = 17.0022(13) Å , b = 112.944(3)°, V = 2070.0(3) Å 3 , 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-HÁÁÁO, O-HÁÁÁN and C-HÁÁÁO 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-HÁÁÁp interactions. Nine 3-(3,4-dimethoxyphenyl)furan-2(5H)-ones were synthesized and fully characterized by elemental analysis, MS and 1 H 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.

In the title compound, C16H12BrN3O4, the furan-2(5H)-one ring forms a dihedral angle of 33.19 (9)° with the 4-bromo­benzene unit and is nearly perpendicular to the 4-nitro­benzene segment, making a dihedral angle of 89.93 (10)°. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules, generating an infinite chain along [010]. The chains are linked into a three-dimensional network by C—H⋯O, C—H⋯π and π–π contacts [centroid–centroid separation = 3.805 (2) Å].

In the title mol­ecule, C10H7ClO3, the butyrolactone core, a furan-2(5H)-one, forms a dihedral angle of 59.21 (5)° with the benzene ring. In the crystal, two types of hydrogen bonds (O—H⋯O and C—H⋯Cl) link mol­ecules into infinite chains along the b axis. π–π contacts [centroid–centroid distances = 3.6359 (10) and 3.8776 (11) Å] link the chains into a three-dimensional network.