Abstract C17H13BrN2, orthorhombic, Pbca (no. 61), a = 9.995(4) Å, b = 13.845(5) Å, c = 20.213(7) Å, V = 2797.2(18) Å3, Z = 8, Rgt(F) = 0.0304, wRref(F2) = 0.0784, T = 296(2) K.

Crystal structure of 2-(4-chlorophenyl)-2,3-dihydro-1H-perimidine, C17H13Cl1N2

An account is given of the development of the SHELX system of computer programs from SHELX-76 to the present day. In addition to identifying useful innovations that have come into general use through their implementation in SHELX, 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. SHELXL is the most widely used program for small-molecule refinement and SHELXS and SHELXD are often employed for structure solution despite the availability of objectively superior programs. SHELXL also finds a niche for the refinement of macromolecules against high-resolution or twinned data; SHELXPRO acts as an interface for macromolecular applications. SHELXC, SHELXD and SHELXE are proving useful for the experimental phasing of macromolecules, especially because they are fast and robust and so are often employed in pipelines for high-throughput phasing. This paper could serve as a general literature citation when one or more of the open-source SHELX programs (and the Bruker AXS version SHELXTL) are employed in the course of a crystal-structure determination.

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A short history of SHELX

2,3-Dichloro-5,6-dicyano-1,4-benzoquinone, a mild catalyst for the formation of carbon-nitrogen bonds

Old reagents, new results: Aromatization of Hantzsch 1,4-dihydropyridines with manganese dioxide and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone

Preparation d'aryl-2 benzimidazoles et deshydratation d'oximes en nitriles par utilisation d'oxyde de triphenylphosphine et d'anhydride triflique comme deshydratant

Seeking the ideal dehydrating reagent

A series of 7-oxo-7H-dibenz[f,ij]isoquinoline and 7-oxo-7H-benzo[e]perimidines bearing cationic side chains were prepared from aminoanthraquinones. The perimidines were prepared from 1-aminoanthraquinone by initial condensation with urea or dimethylacetamide. A series of 2-, 4-, 8-, and 11-carboxy derivatives of the dibenzisoquinolines were prepared from aminoanthraquinonecarboxylic acids. The cationic derivatives were prepared from these via amide, amine, or methylene linkers to study the effects of side chain positioning on biological activity. Within the series of carboxamide-linked compounds, the order of increasing cytotoxicity was 8- < 4- < 2- < 11-. The 2- and 4-carboxamides showed substantial growth delays against in vivo subcutaneous colon 38 tumors in mice, but the 11-carboxamide had curative activity in this refractory model and is being investigated further.

Crystal structure of 2-(4-chlorophenyl)-2,3-dihydro-1H-perimidine, C17H13Cl1N2

References

A short history of SHELX

2,3-Dichloro-5,6-dicyano-1,4-benzoquinone, a mild catalyst for the formation of carbon-nitrogen bonds

Old reagents, new results: Aromatization of Hantzsch 1,4-dihydropyridines with manganese dioxide and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone

Seeking the ideal dehydrating reagent

Synthesis and cytotoxic activity of 7-oxo-7H-dibenz[f,ij]isoquinoline and 7-oxo-7H-benzo[e]perimidine derivatives.