In the title compound, C(6)H(12)N(2)O(2)S, the heterocyclic ring has a sofa conformation. The mol-ecular conformation is stabilized by an intra-molecular O-H⋯O hydrogen-bond inter-action with graph-set motif S(6). In the crystal, mol-ecules are linked by O-H⋯S, N-H⋯S and N-H⋯O hydrogen-bond inter-actions, forming an extended two-dimensional framework parallel to the ac plane.

The title compound, C(8)H(9)NO(4)S, is of inter-est as a precursor to biologically active sulfur-containing heterocyclic cmpounds. The crystal structure displays the classical O-H⋯O inter-molecular hydrogen bonding typical for carboxylic acids forming dimers. Symmetry-related dimers are, in turn, linked through head-to-tail pairs of inter-molecular N-H⋯O inter-actions, giving rise to a zigzag c...

In the isoquinoline ring system of the title compound, C(19)H(22)N(2)O(5), the N-heterocyclic ring is in a half-chair conformation. The dioxa-2-aza-spiro ring is essentially planar [maximum deviation of 0.025 (1) Å] and forms a dihedral angle of 23.51 (5)° with the benzene ring. In the crystal, mol-ecules are linked via weak inter-molecular C-H⋯O and C-H⋯N hydrogen bonds into chains along [010].

The title compound, C(12)H(9)NO(2)S, belongs to the nitro-gen-containing group of heterocyclic organic compounds and crystallized with two mol-ecules per asymmetric unit. In the crystal, both molecules form inversion dimers linked by pairs of O-H-O hydrogen bonds. Weak symmetry-related C-H-O inter-actions link the carboxyl dimers along b axis. The dihedral angle between the two aromatic rings i...

In the title compound, C(10)H(9)N(3)O(3), the benzene ring is almost coplanar with the heterocyclic ring, making a dihedral angle of 11.3 (1)°. The plane of the carboxyl group is rotated by 8.4 (2)° with respect to the 1,2,4-oxadiazole ring plane. The aliphatic chain exhibits an extended conformation. In the crystal, mol-ecules are liked through inter-molecular O-H⋯N bonds, forming a chain stru...

The reaction of cyanoacetyl hydrazine (1) with 3-acetylpyridine (2) gave the hydrazide-hydrazone derivative 3. The latter compound undergoes a series of heterocyclization reactions to give new heterocyclic compounds. The antitumor evaluation of the newly synthesized products against three cancer cell lines, namely breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and CNS canc...

Pyrazole is a five membered heterocyclic ring which is a versatile leading compound for designing potent bioactive agents. This interesting group of compounds has diverse biological activities such as antimicrobial, anti-inflammatory, analgesic, anticonvulsant, anticancer, anthelmintic, antioxidant and herbicidal. Results of numerous derivatives of different pyrazole and their substitutions are...

The asymmetric unit of the title compound, C54H64O12S4, consists of one half of the mol-ecule, which is located on an inversion centre. The heterocyclic six-membered ring adopts a distorted envelope conformation with the spiro C atom as the flap. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds with an R (2) 2(14) motif, forming a chain along the b-axis direction.

In the title compound, C(18)H(16)O(2), the heterocyclic ring of the chroman-2-one system adopts a slightly distorted screw-boat conformation. The dihedral angle between the least-squares planes of the coumarin ring system and the benzene ring is 67.5 (1)°. The crystal packing features C-H⋯O hydrogen bonds, which link the mol-ecules into centrosymmetric R(2) (2)(8) dimers, and C-H⋯π inter-actions.

The title compound, C(26)H(34)O(11), known as bruceine A, is a natural quassinoid extracted from the dried fruits of Brucea javanica. Its structure consists of five fused rings including an oxygen-containing heterocyclic ring and a lactone ring. Two intra-molecular O-H⋯O links help to establish the mol-ecular conformation. In the crystal, O-H⋯O hydrogen bonds connect the mol-ecules.