(2RS)-3-(4-Hydroxyphenyl)-2-(1-oxo-1H-2,3-dihydroisoindol-2-yl)propanoic acid monohydrate

The title compound, C₁₇H₁₅NO₄·H₂O, derived from DL-tyrosine crystallizes as an unusual hydrogen-bonded acid-monohydrate dimer. The asymmetric unit contains two organic molecules and two water molecules. Dimers link through (aryl)O-H...O=C hydrogen bonds along the [101] direction, forming a one-dimensional chain of rings, and further associated via inversion centres (forming a chain of rings aligned in the opposite direction) generating columns. Ruffled sheets arise from interlocking of isoindole rings via π-π(arene) stacking and C-H...π(arene) interactions; C-H...O interactions generate a three-dimensional network

O-H...O, C-H...O and C-H...[pi]arene intermolecular interactions in (2S)-2-(1-oxo-1H-2,3-dihydroisoindol-2-yl)pentanoic acid and (2S)-3-methyl-2-(1-oxo-1H-2,3-dihydroisoindol-2-yl)butanoic acid

In the first of the title compounds, (2S)-2-(1-oxo-1H-2,3-dihydroisoindol-2-yl)pentanoic acid, C₁₃H₁₅NO₃, prepared from L-norvaline, a hydrogen-bonded network is formed in the solid state through O-H...O=C, C-H...O=C and C-H...πarene intermolecular interactions, with shortest O...O, C...O and C...centroid distances of 2.582 (13), 3.231 (11) and 3.466 (3) Å, respectively. In the L-valine derivative, (2S)-3-methyl-2-(1-oxo-1H-2,3-dihydroisoindol-2-yl)butanoic acid, C₁₃H₁₅NO₃, O-H...O=C and Carene-H...O=C intermolecular interactions generate a cyclic R²₂(9) motif through cooperativity, with shortest O...O and C...O distances of 2.634 (3) and 3.529 (5) Å, respectively. Methylene C-H...O=Cindole interactions complete the hydrogen bonding, with C...O distances ranging from 3.283 (4) to 3.477 (4) Å

Structural systematics and conformational analyses of a 3×3 isomer grid and three chlorinated relatives

The focus of our research is to bridge solid state structural studies with computational (ab initio) modelling methods by exploring the influence of different functional groups and their position in semi-rigid small drug-like molecules.1-3 A 3×3 isomer grid of nine N-(tolyl)pyridinecarboxamides (C13H12N2O) as NxxM (x = para-/meta-/ortho-) (Scheme 1A) has been synthesised and characterised to evaluate and correlate structural relationships from both solid-state (Table 1, Figs. 1,2,4) and ab initio calculations (Fig. 3). The effect of pyridinoyl group (Nx) and methyl group (xM) substitution patterns on molecular structure and conformations (syn/anti, Scheme 1B) from calculations (gas phase and solvated forms), as well as on crystal packing and conformations in solid state is explored, allowing evaluation and rationalisation of disorder and unexpected conformations in the solid state structures

(2S)-4-Methyl-2-(1-oxo-1H-2,3-dihydroisoindol- 2-yl)pentanoic acid.

The title compound, C14H17NO3, exhibits carboxylic acid group disorder about the C—CO2 axis, with site occupancies of 0.79 (5):0.21 (5). Molecules are linked by intermolecular O—H O Ciso, C—H O Ciso and C—H (arene) interactions (iso = isoindolinone)

Structural systematic studies and conformational analyses of a 3x3 isomer grid of fluoro-N-(pyridyl)benzamides; physicochemical correlations, polymorphism and isomorphous relationships

The effect of fluorine and pyridine N atom substitution patterns on molecular structure and conformation is probed in a 3 3 isomer grid (Scheme 1) of fluoro-N-(pyridyl)benzamides (Fxx) (C12H9N2OF, x = para-/meta-/ortho-) to evaluate and correlate structural relationships between the solid-state and ab initio calculations. Physicochemical comparisons are analysed with an extended series of three related 3 x 3 isomer grids. Our analysis integrates crystal structure analyses, computational chemistry and conformational analyses together with NMR data and physicochemical trends such as melting point analysis. This study concludes structural systematics survey of four fluoro/methyl substituted benzamide/pyridinecarboxamide isomer grids

Entry point into new trimeric and tetrameric imide-based macrocyclic esters derived from isophthaloyl dichloride and methyl 6-aminonicotinate

The one-step reaction of isophthaloyl dichloride with the 2-aminopyridine derivative (methyl 6-aminonicotinate) yields (i) a trimer-based macrocycle (EsIO)3 and (ii) a tetramer-based macrocycle (EsIO)4 in modest isolated synthetic yields (total of 25%), together with (iii) longer open-chain oligomers. The macrocyclisation relies on the semi-flexible imide hinge formed by reaction of the 2-amino(pyridine) functional group with two acyl chloride functional groups. The determining factors in macrocycle synthesis are (a) imide formation using the heteroaromatic ortho-N functionality; (b) the inherent ability of the imide to twist by 85-115 degrees from planarity (as measured by the CO...CO imide torsion angles and from computational calculations), thereby providing a hinge for macrocyclic ring closure or potentially (non)helical assembly in oligomer/polymer formation and (c) the conformational flexibility of the isophthaloyl group with meta-related carbonyl groups to twist and adopt either syn- or anti-conformations, although the syn-conformation is observed structurally for all isophthaloyl groups in both (EsIO)3 and (EsIO)4 macrocycles

3-Fluoro-N-(3-fluorobenzoyl)-N-(2-pyridyl)benzamide

The title compound, C19H12F2N2O2, a 2:1 product of the reaction of 3-fluorobenzoylchloride and 2-aminopyridine crystallizes with a disordered 3-fluorobenzene ring adopting two conformations [ratio of occupancies 0.959 (4):0.041 (4)]. In the crystal structure, there are no classical hydrogen bonds and interactions comprise C-H...O in the form 2(C-H)...O=C [with motif R21(5)]; C-H...[pi](arene) interactions are also present

Intermolecular C-H...N and C-H...O interactions in (2S,4S,5R)-(-)-3,4-dimethyl-5-phenyl-2-(1,3-thiazol-2-yl)-1,3-oxazolidine

The title compound, C₁₄H₁₆N₂OS, prepared from (1R,2S)-(-)-ephedrine, contains the oxazolidine ring in an envelope conformation, with the nitrogen atom 0.623 (2) Å from the plane of the other four oxazolidine ring atoms. Intermolecular C--H...N and C--H...O interactions generate a two-dimensional hydrogen-bonded network, with shortest C...N and C...O distances of 3.403 (3) and 3.463 (2) Å, respectively

Intermolecular interactions in the chiral and racemic forms of 3-hydroxy-2-(1-oxoisoindolin-2-yl)butanoic acid derived from threonine

The title compounds, C₁₂H₁₃NO₄, are derived from L-threonine and DL-threonine, respectively. Hydrogen bonding in the chiral derivative, (2S/3R)-3-hydroxy-2-(1-oxoisoindolin-2-yl)butanoic acid, consists of O-Hacid...Oalkyl-H...O=Cindole chains [O...O 2.659 (3) and 2.718 (3) Å], Csp³-H...O and three C-H...πarene interactions. In the (2R,3S/2S,3R) racemate, conventional carboxylic acid hydrogen bonding as cyclical (O-H...O=C)₂ [graph set R₂²(8)] is present, with Oalkyl-H...O=Cindole, Csp³-H...O and C-H...πarene interactions. The COOH group geometry differs between the two forms, with C-O, C=O, C-C-O and C-C=O bond lengths and angles of 1.322 (3) and 1.193 (3) Å, and 109.7 (2) and 125.4 (3)°, respectively, in the chiral structure, and 1.2961 (17) and 1.2210 (18) Å, and 113.29 (12) and 122.63 (13)°, respectively, in the racemate structure. The O-C=O angles of 124.9 (3) and 124.05 (14)° are similar. The differences arise from the contrasting COOH hydrogen-bonding environments in the two structures

2-(3,5-Dimethylbenzene)-1-ferrocenylmethyl-1H-1,3-benzimidazole

In the title molecule, [Fe(C5H5)(C21H19N2)], the five-membered imidazole ring forms dihedral angles of 88.61 (8) and 42.15 (6)° with the substituted cyclopentadienyl and dimethyl-substituted benzene rings, respectively. In the crystal structure, there is an Nsp2...H contact and a modest C-H...[pi](arene) interaction involving the benzene ring of the benzimidizole system