Examination of the symmetric Hantzsch 1,4-dihydropyridine ester derivatives of the prototypical nifedipine molecule indicates the tendency of this class of molecule to form a common packing motif. Crystal structure analysis of 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic diesters and analogs reveals that they form extended chains, characterized as the C(6) packing motif, via intermolecular (amine) N—H...O=C (C3,C5 carbonyl) hydrogen bonds. In addition, all the prepared derivatives also satisfy the basic structural requirements for their high binding efficiency to the receptor. The reproducible C (6) packing motif observed among these compounds has a use in the design of solid-state materials.

Vijayakumar V

Department of Chemistry

School of Advanced Sciences

Vellore Campus

Rathore R.S

Reddy B.P

Ragavan R.V

Narasimhamurthy T.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Hantzsch 1,4-dihydropyridine esters and analogs: candidates for generating reproducible one-dimensional packing motifs

Acta Crystallographica Section B Structural Science

Abstract Synthesis of 1,4-dihydropyridines by three-component condensation reaction of aldehyde, 1,3-dicarbonyl compounds, and ammonium acetate have been found to be efficiently catalyzed by uranyl nitrate hexahydrate [UO2(NO3)2 ·6H2O] at room temperature under ultrasound irradiation. This novel synthetic method offers the advantages of high yields, short reaction times, simplicity, and easy workup compared to the conventional methods reported in the literature. © 2014 Springer Science+Business Media Dordrecht.

Research on Chemical Intermediates

Ultrasound-mediated, uranyl nitrate hexahydrate-catalyzed synthesis of 1,4-dihydropyridines under mild conditions

Highly regioselective reaction of some substituted 2,4-dichloroquinolines with symmetrical 1,4-dihydropyridines, leading to novel quinoline derivatives of DHPs, has been achieved in the presence of powdered K2CO 3, as a mild and efficient base, at moderate temperature. All the synthesized compounds were characterized by use of IR, NMR, and mass spectral data. © 2013 Springer Science+Business Media Dordrecht.

Regioselective synthesis of novel 2-chloroquinoline derivatives of 1,4-dihydropyridines

Bi-, tri- and tetrapodal polyhydroquinolines and 1,4-dihydropyridines were synthesised by the reaction of various alkylating agents with polyhydroquinolines and 1,4-dihydropyridines under sonication conditions. These were in turn converted to the corresponding pyridines also using sonication. Sonication produced higher yields in a faster reaction time. All the synthesized compounds were characterized using spectral data. © 2014 The Royal Society of Chemistry.

RSC Adv.

Ultrasound-promoted synthesis of bi-, tri- and tetrapodal polyhydroquinolines, 1,4-dihydropyridines and the corresponding pyridines

The asymmetric unit of the title compound, C 25H 35NO 6, contains two independent molecules. In each molecule, the 1,4-dihydropyridine ring adopts a flattened boat conformation. The dihedral angles between the 1,4-dihydropyridine and benzene rings are 87.55 (7) and 87.23 (7)°. In one of these molecules, one of the isobutyl groups is disordered over two sets of sites, with an occupancy ratio of 0.890 (2):0.110 (2). In the crystal, molecules are linked through N - H⋯O, O - H⋯O and C - H⋯O hydrogen bonds forming two-dimensional networks parallel to the ab plane. The crystal structure is further stabilized by weak C - H⋯π interactions.

Fulltext

Acta Crystallographica Section E Structure Reports Online

Diisobutyl 4-(3-ethoxy-4-hydroxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate

In the title compound, C 19H 20F 6N 2O 8, the ethoxy and ethyl groups are disordered over two sets of sites, with occupancy ratios of 0.212 (18):0.788 (18) and 0.746 (6):0.254 (6), respectively. The piperidine ring adopts a chair conformation. In the molecule, intramolecular O - H⋯O hydrogen bonds form two S(6) ring motifs. In the crystal, molecules are linked via O - H⋯O and C - H⋯O hydrogen bonds, forming dimers.

Diethyl 2,6-dihydroxy-4-(3-nitrophenyl)-2,6-bis(trifluoromethyl)piperidine-3,5-dicarboxylate

Acta Crystallographica Section C Crystal Structure Communications

Hydrogen-bonded sheets in 2-(2-aminophenyl)-1H-benzimidazol-3-ium dihydrogen phosphate

<jats:p>An account is given of the development of the<jats:italic>SHELX</jats:italic>system of computer programs from<jats:italic>SHELX</jats:italic>-76 to the present day. In addition to identifying useful innovations that have come into general use through their implementation in<jats:italic>SHELX</jats:italic>, a critical analysis is presented of the less-successful features, missed opportunities and desirable improvements for future releases of the software. An attempt is made to understand how a program originally designed for photographic intensity data, punched cards and computers over 10000 times slower than an average modern personal computer has managed to survive for so long.<jats:italic>SHELXL</jats:italic>is the most widely used program for small-molecule refinement and<jats:italic>SHELXS</jats:italic>and<jats:italic>SHELXD</jats:italic>are often employed for structure solution despite the availability of objectively superior programs.<jats:italic>SHELXL</jats:italic>also finds a niche for the refinement of macromolecules against high-resolution or twinned data;<jats:italic>SHELXPRO</jats:italic>acts as an interface for macromolecular applications.<jats:italic>SHELXC</jats:italic>,<jats:italic>SHELXD</jats:italic>and<jats:italic>SHELXE</jats:italic>are proving useful for the experimental phasing of macromolecules, especially because they are fast and robust and so are often employed in pipelines for<jats:italic>high-throughput</jats:italic>phasing. This paper could serve as a general literature citation when one or more of the open-source<jats:italic>SHELX</jats:italic>programs (and the Bruker AXS version<jats:italic>SHELXTL</jats:italic>) are employed in the course of a crystal-structure determination.</jats:p>

Journal	Acta Crystallographica Section B Structural Science
Publisher	International Union of Crystallography (IUCr)
ISSN	0108-7681
Open Access	0