Crystal structure and Hirshfeld surface analysis of (Z)-4-{[4-(3-methyl-3-phenylcyclobutyl)thiazol-2-yl]amino}-4-oxobut-2-enoic acid

The title cyclobutyl compound, C18H18N2O3S, was synthesized by the interaction of 4-(3-methyl-3-phenylcyclobutyl)thiazol-2-amine and maleic anhydride, and crystallizes in the orthorhombic space group P212121 with Z′ = 1. The molecular geometry is partially stabilized by an intramolecular N—H...O hydrogen bond forming an S 1 1(7) ring motif. The molecule is non-planar with a dihedral angle of 88.29 (11)° between the thiazole and benzene rings. In the crystal, the molecules are linked by O—H...N hydrogen bonds, forming supramolecular ribbons with C 1 1(9) chain motifs. To further analyze the intermolecular interactions, a Hirshfeld surface analysis was performed. The results indicate that the most important contributions to the overall surface are from H...H (43%), C...H (18%), O...H (17%) and N...H (6%), interactions.

Crystal structure and Hirshfeld surface analysis of 3-[2-(3,5-dimethylphenyl)hydrazinylidene]benzofuran-2(3H)-one

In the title compound, C16H14N2O2, the 2,3-dihydro-1-benzofuran ring system is essentially planar and makes a dihedral angle of 3.69 (7)° with the dimethylphenyl ring. The molecular conformation is stabilized by an intramolecular N—H...O hydrogen bond with an S(6) ring motif. In the crystal, molecules are connected by C—H...π and π–π stacking interactions, forming a layer lying parallel to the (11\overline{1}) plane. One methyl group is disordered over two orientations, with occupancies of 0.67 (4) and 0.33 (4). Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (51.2%), O...H/H...O (17.9%), C...H/H...C (15.2%) and C...C (8.1%) contacts.

Crystal structure and Hirshfeld surface analysis of (Z)-2-{[(2,4-dimethylphenyl)imino]methyl}-4-methylphenol

The title compound, C16H17NO, is a Schiff base that exists in the enol–imine tautomeric form and adopts a Z configuration. The molecule is non-planar, with the twisted rings making a dihedral angle of 39.92 (4)°. The intramolecular O—H...N hydrogen bond forms an S(6) ring motif. In the crystal, molecules are linked by C—H...π interactions and very weak π-π stacking interactions also help to consolidate the crystal packing. A Hirshfeld surface analysis was performed to investigate the contributions of different intermolecular contacts within the supramolecular structure. The major contributions are from H...H (65%), C...H (19.2%) and O...H (6.6%) interactions.

Crystal structure and Hirshfeld surface analysis of (3Z)-7-methoxy-3-(2-phenylhydrazinylidene)-1-benzofuran-2(3H)-one

In the title compound, C15H12N2O3, pairs of molecules are linked into dimers by N—H...O hydrogen bonds, forming an R 2 2(12) ring motif, with the dimers stacked along the a axis. These dimers are connected through π–π stacking interactions between the centroids of the benzene and furan rings of their 2,3-dihydro-1-benzofuran ring systems. Furthermore, there exists a C—H...π interaction that consolidates the crystal packing. A Hirshfeld surface analysis indicates that the most important contacts are H...H (40.7%), O...H/H...O (24.7%), C...H/H...C (16.1%) and C...C (8.8%).

Crystal structure and Hirshfeld surface analysis of dimethyl 5-[2-(2,4,6-trioxo-1,3-diazinan-5-ylidene)hydrazin-1-yl]benzene-1,3-dicarboxylate 0.224-hydrate

In the crystal, the whole molecule of the title compound, C14H12N4O7·0.224H2O, is nearly planar with a maximum deviation from the least-squares plane of 0.352 (1) Å. The molecular conformation is stabilized by an intramolecular N—H...O hydrogen bond, generating an S(6) ring motif. In the crystal, molecules are linked by centrosymmetric pairs of N—H...O hydrogen bonds, forming ribbons along the c-axis direction. These ribbons connected by van der Waals contacts, forming sheets parallel to the ac plane. There are also intermolecular van der Waals contacts and and C—H...π interactions between the sheets. A Hirshfeld surface analysis indicates that the most prevalent interactions are O...H/H...O (41.2%), H...H (19.2%), C...H/H...C (12.2%) and C...O/ O...C (8.4%).

Crystal structure and Hirshfeld surface analysis of ethyl 6′-amino-2′-(chloromethyl)-5′-cyano-2-oxo-1,2-dihydrospiro[indoline-3,4′-pyran]-3′-carboxylate

The molecular conformation of the title compound, C17H14ClN3O4, is stabilized by an intramolecular C—H...O contact, forming an S(6) ring motif. In the crystal, the molecules are connected by N—H...O hydrogen-bond pairs along the b-axis direction as dimers with R 2 2(8) and R 2 2(14) ring motifs and as ribbons formed by intermolecular C—H...N hydrogen bonds. There are weak van der Waals interactions between the ribbons. The most important contributions to the surface contacts are from H...H (34.9%), O...H/H...O (19.2%), C...H/H...C (11.9%), Cl...H/H...Cl (10.7%) and N...H/H...N (10.4%) interactions, as concluded from a Hirshfeld surface analysis.

Solid-Phase Synthesis of an Insect Pyrokinin Analog Incorporating an Imidazoline Ring as Isosteric Replacement of a trans Peptide Bond

A facile solid-phase synthetic method for incorporating the imidazoline ring motif, a surrogate for a trans peptide bond, into bioactive peptides is reported. The example described is the synthesis of an imidazoline peptidomimetic analog of an insect pyrokinin neuropeptide via a cyclization reaction of an iminium salt generated from the preceding amino acid and 2,4-diaminopropanoic acid (Dap).

Solid Phase Synthesis of an Insect Pyrokinin Analog Incorporating an Imidazoline Ring as Isosteric Replacement of a trans Peptide Bond

A facile solid-phase synthetic method for incorporating the imidazoline ring motif, a surrogate for a trans peptide bond, into bioactive peptides is reported. The example described is the synthesis of an imidazoline peptidomimetic analog of an insect pyrokinin neuropeptide via a cyclization reaction of an iminium salt generated from the preceding amino acid and 2,4-diaminopropanoic acid (Dap).

4-Bromo-2-[({2-[(2-hydroxyethyl)amino]ethyl}imino)methyl]phenol

The new title Schiff base compound, C11H15BrN2O2, crystallizes in the monoclinic space group P21 with two independent molecules in the asymmetric unit. It was prepared by the condensation reaction of 5-bromo-2-hydroxybenzaldehyde and aminoethylethanolamine. There is an intramolecular O—H...N hydrogen bond with an S(6) ring motif. Moreover, there are intermolecular C—H...N, C—H...O and Br...O interactions in the crystal structure of the title compound.

Crystal structures of 1-(4-chlorophenyl)-4-(4-methylphenyl)-2,5-dioxo-1,2,5,6,7,8-hexahydroquinoline-3-carboxylic acid and 4-(4-methoxyphenyl)-1-(4-methylphenyl)-2,5-dioxo-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile

In the title compounds C23H21ClN2O3 [I, namely 1-(4-chlorophenyl)-4-(4-methylphenyl)-3,8-dioxo-1,2,5,6,7,8-hexahydroquine-3-carboxylic acid] and C24H22N2O3 [II, namely 4-(4-methoxyphenyl)-1-(4-methylphenyl)-2,5-dioxo-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile], each of the cyclohexene and dihydropyridine rings of the 1,2,5,6,7,8-hexahydroquinoline moieties adopts a twisted-boat conformation. The asymmetric units of both compounds I and II consist of two independent molecules (A and B). In II A, three carbon atoms of the cyclohexene ring are disordered over two sets of sites in a 0.670 (11):0.330 (11) occupancy ratio. In the crystal of I, molecules are linked through classical N—H...O hydrogen bonds, forming inversion dimers with an R 2 2(8) ring motif and with their molecular planes parallel to the crystallographic (020) plane. Non-classical C—H...O hydrogen-bonding interactions connect the dimers, resulting in a three-dimensional network. In the crystal of II, molecules are linked by C—H...N, C—H...O and C—H...π interactions, forming a three-dimensional network.