ABSTRACT: The mol-ecule of the title oxobutanoate derivative, C(12)H(13)ClN(2)O(3), adopts a keto-hydrazo tautomeric form and is roughly planar, the angle between the benzene ring and the mean plane through the hydrazone and aliphatic chain being 1.49?(6)°. This planarity is further aided by the formation of an intra-molecular N-H?O hydrogen bond which generates an S(6) ring motif. The aromatic ring and aliphatic chain have a trans configuration with respect to the N-N bond. In the crystal packing, centrosymmetric R(2) (2)(16) dimers are formed through pairs of weak C-H?O(3-oxo) inter-actions. These dimers are linked together through weak C-H?O(carboxyl-ate C=O) inter-actions into ribbons along the b-axis direction. These ribbons are stacked along the a-axis direction. The crystal also exhibits Cl?Cl [3.4988?(6)?Å] and C?O [3.167?(2)-3.335?(2)?Å] short contacts.
Project description:The mol-ecule of the title oxobutanoate derivative, C(12)H(13)ClN(2)O(3), is nearly planar; the inter-planar angle between the benzene ring and the mean plane through the hydrazono-3-oxobutanoate unit is 2.69?(3)°. An intra-molecular N-H?O hydrogen bond generates an S(6) ring motif. In the crystal packing, C-H?O(3-oxo) inter-actions link mol-ecules into dimers. The dimers thus formed are linked through C-H?O(carboxyl-ate C=O) inter-actions, leading to the formation of ribbons along the  direction, which are stabilized via Cl?Cl [3.2916?(3)?Å] contacts. The ribbons are stacked via C?O contacts [3.2367?(12)-3.3948?(12)?Å].
Project description:The title compound, C(12)H(12)Cl(2)N(2)O(3), crystallizes as a non-merohedral twin with a twinning ratio of 0.51:0.49. The mol-ecule adopts a keto-hydrazo tautomeric form stabilized by an intra-molecular N-H?O hydrogen bond. The configuration around the N-N bond is trans.
Project description:In the title compound, C25H15Cl2NO4S, the di-chloro-phenyl ring is twisted by 68.69?(11)° from the mean plane of the carbazole ring system [r.m.s. deviation = 0.084?(2)°]. The hy-droxy group is involved in an intra-molecular O-H?O hydrogen bond, which generates an S(6) graph-set motif. In the crystal, pairs of C-H?Cl hydrogen bonds link mol-ecules into inversion dimers with an R (2) 2(26) motif. Weak C-H?O inter-actions further link these dimers into ribbons propagating in .
Project description:Methods are described for identifying the 2,4-dinitrophenylhydrazones of 4-methylthio-2-oxobutanoate by means of t.l.c., n.m.r. and mass spectroscopy. By using these methods 4-methylthio-2-oxobutanoate, a putative intermediate in the biosynthesis of ethylene from methionine, has been identified in culture fluids of Aeromonas hydrophila B12E and a coryneform bacterium D7F grown in the presence of methionine. Relative to 4-methylthio-2-oxobutanoate, the yield of 3-(methylthio)propanal (methional) from the same cultures was less than 1%. Because 4-[2H]methylthio-2-oxobutanoate was obtained from cultures grown on [Me-2H]methionine, the 4-methylthio-2-oxobutanoate must be derived from methionine. By means of t.l.c. alone, 4-methylthio-2-oxobutanoate was identified in the culture fluids of a range of bacteria, the yeast Saccharomyces cerevisiae and the fungus Penicillium digitatum. A photochemical assay developed for 4-methylthio-2-oxobutanoate shows it to be a product of the metabolism of methionine by Escherichia, Pseudomonas, Bacillus, Acinetobacter, Aeromonas, Rhizobium and Corynebacterium species.
Project description:In the title compound, C(20)H(31)Cl(2)N(2)O(6)PSi, the dioxaphospho-rinane ring adopts a cis conformation. The silatrane fragment forms a cage-like structure in which there exists an intra-molecular Si-N donor-acceptor bond. In the crystal, centrosymmetrically related mol-ecules are linked by pairs of N-H?O hydrogen bonds into inversion dimers, generating rings with graph-set motif R(2) (2)(8). The dimers are further connected into ribbons parallel to the a axis by inter-molecular C-H?O hydrogen bonds.
Project description:In the title compound, C16H13Cl2N3O3S2, the thio-phene ring is disordered in a 0.762?(3):0.238?(3) ratio by an approximate 180° rotation of the ring around the S-C bond linking the ring to the sulfonyl unit. The di-chloro-benzene group is also disordered over two sets of sites with the same occupancy ratio. The mol-ecular conformation is stabilized by intra-molecular C-H?Cl and C-H?N hydrogen bonds, forming rings with graph-set notation S(5). In the crystal, pairs of mol-ecules are linked by N-H?O and C-H?O hydrogen bonds, forming inversion dimers with graph-set notation R22(8) and R12(11), which are connected by C-H?O hydrogen-bonding inter-actions into ribbons parallel to (100). The ribbons are further connected into a three-dimensional network by C-H?? inter-actions and ?-? stacking inter-actions between benzene and thio-phene rings, with centroid-to-centroid distances of 3.865?(2), 3.867?(7) and 3.853?(2)?Å. Hirshfeld surface analysis has been used to confirm and qu-antify the supra-molecular inter-actions.
Project description:In the title compound, C14H14Cl2N2O3, the chloro-phenyl ring makes a dihedral angle of 87.08?(9)° with the tetra-hydro-pyrimidine ring. There is a short intra-molecular C-H?O contact present. In the crystal, mol-ecules are linked via pairs of N-H?O hydrogen bonds, forming inversion dimers with an R (2) 2(8) ring motif. The dimers are linked via a second pair of N-H?O hydrogen bonds, this time enclosing an R (4) 4(20) ring motif, forming ribbons along . The ribbons are linked via C-H?O hydrogen bonds, forming sheets lying parallel to (001). The terminal ethyl group is disordered over two positions with an occupancy ratio of 0.654?(17):0.346?(17).
Project description:The title compound, C(5)H(6)N(2)O(2), was prepared from 2-methyl-pyrazine, acetic acid and hydrogen peroxide. In the crystal, ?-? stacking inter-actions between neighboring mol-ecules are observed, with a centroid-centroid distance of 3.7370?Å, an inter-planar distance of 3.167?Å, and a slippage of 1.984?Å. Each mol-ecule is linked to four neighbors through C-H?O hydrogen-bonding inter-actions, forming one-dimensional ribbons.
Project description:Carvacrol (1) and thymol (2) were converted to their alkyl 4-oxobutanoate derivatives (7-20) in three steps, and evaluated for tyrosinase inhibitory activity. The compounds showed structure-dependent activity, with all alkyl 4-oxobutanoates, except 7 and 20, showing better inhibitory activity than the precursor 4-oxobutanoic acids (5 and 6). In general, thymol derivatives exhibited a higher percent inhibitory activity than carvacrol derivatives at 500??M. Derivatives containing three-carbon and four-carbon alkyl groups gave the strongest activity (carvacrol derivatives 9-12, IC50?=?128.8-244.1??M; thymol derivatives 16-19, IC50?=?102.3-191.4??M).
Project description:The title compound, C12H11NO3, is essentially planar, with the mean plane of the acetate side chain [-C-C(=O)-O-C] being inclined to the mean plane of the indole ring system by 12.49?(7)°. The five- and six-membered rings of the indole group are almost coplanar, making a dihedral angle of 1.76?(8)°. The conformation about the C=C bond is E and there is an intra-molecular C-H?O hydrogen bond present. In the crystal, mol-ecules are linked by pairs of C-H?O hydrogen bonds forming inversion dimers, with an R 2 (2)(16) ring motif. The dimers are linked by a second pair of C-H?O hydrogen bonds, enclosing R 2 (2)(16) ring motifs, forming ribbons lying parallel to (-114). The ribbons are linked via C-H?? inter-actions, forming a three-dimensional structure.