Crystal structure of 4-(4'-diethylaminophenyl)-6-(4-methoxyphenyl)-(2-pyrrolidin-1-yl)-pyridine-3-carbonitrile.

4-(4'-Diethylaminophenyl)-6-(4-methoxyphenyl)-(2-pyrrolidin-1-yl)-pyridine-3-carbonitrile (DMPPC) was studied by X-ray diffraction methods due to its non-linear optical properties. The pyrrolidine and pyridine rings adopt half-chair and planar conformations, respectively. The molecules in the crystal are stabilized by C-H...O and C-H...N types of intermolecular interactions in addition to van der Waals forces.     

One-Pot Three-Component Synthesis of a Series of 2-Amino-4-(4-oxo-4H-chromen-3-yl)-5-(2,2,2-trifluoroacetyl)-6-(trifluoromethyl)-4H-pyrans and 2-Amino-4-(4-oxo-4H-chromen-3-yl)-5-(thiophene-2-carbonyl)-6-(trifluoromethyl)-4H-pyrans as Promising Anticancer Agents

Russian Journal of Organic Chemistry - Novel functionalized 2-amino-4-(4-oxo-4H-chromen-3-yl)-5-(2,2,2-trifluoroacetyl)-6-(trifluoro­methyl)-4H-pyrans and...     

Theoretical study on the repair mechanism of the (6-4) photolesion by the (6-4) photolyase

UV irradiation of DNA can lead to the formation of mutagenic (6-4) pyrimidine-pyrimidone photolesions. The (6-4) photolyases are the enzymes responsible for the photoinduced repair of such lesions. On the basis of the recently published crystal structure of the (6-4) photolyase bound to DNA [Maul et al. 2008] and employing quantum mechanics/molecular mechanics techniques, a repair mechanism is proposed, which involves two photoexcitations. The flavin chromophore, initially being in its reduced anionic form, is photoexcited and donates an electron to the (6-4) form of the photolesion. The photolesion is then protonated by the neighboring histidine residue and forms a radical intermediate. The latter undergoes a series of energy stabilizing hydrogen-bonding rearrangements before the electron back transfer to the flavin semiquinone. The resulting structure corresponds to the oxetane intermediate, long thought to be formed upon DNA-enzyme binding. A second photoexcitation of the flavin promotes another electron transfer to the oxetane. Proton donation from the same histidine residue allows for the splitting of the four-membered ring, hence opening an efficient pathway to the final repaired form. The repair of the lesion by a single photoexcitation was shown not to be feasible.     

Das Mischkristallsystem (NH4)2ReCl6-;(NH4)2SnCl6

The Mixed Crystal System (NH₄)₂ReCl₆? (NH₄)₂SnCl₆ Homogeneous mixed crystals between (NH₄)₂ReCl₆ and (NH₄)₂SnCl₆ have been prepared in any composition ratio by precipitation from concentrated solutions with concentrated hydrochloric acid. The lattice constants follow VEGARD 'S rule.     

Synthesis of 4- and 6-(tetrazolylmethyl)pentanitrohexaazaisowurtzitanes

Russian Chemical Bulletin - A series of new 4- and 6-(tetrazolylmethyl)pentanitrohexaazaisowurtzitanes were synthesized. The reactions of 4- and 6-(chloromethyl)pentanitrohexaazaisowurtzitanes with...     

Synthesis and mesomorphic properties on the series of 2-(4-alkylphenyl)-6-methylquinolines and 2-(4-alkoxyphenyl)-6-methylquinolines

Two homologous series of quinoline-containing liquid crystalline compounds were synthesised. Preparation of these compounds was completed in a short two-step reaction. Fair to good two-step overall yields of 63%–68%?and 50%–60%?were obtained respectively for the liquid crystalline compounds of 2-(4-alkylphenyl)-6-methylquinolines (nPQMe, n?=?4–8) and 2-(4-alkoxyphenyl)-6-methylquinolines (mOPQMe, m?=?3–7). Spectral analyses were in accordance with the expected structures. Polarising optical microscopy showed both series of compounds only display a nematic phase. Their thermotropic behaviours were further confirmed by differential scanning calorimetry.     

Bromo derivatives of 1-(4-hydroxyphenyl)dihydrouracil and 1-(4-hydroxyphenyl)-5- or -6-metehyldihydrouracils

Bromination of 1-(4-hydroxyphenyl)dihydrouracil and its 6-methyl derivative with bromine in refluxing acetic acid gave 1-(3,5-dibromo-4-hydroxyphenyl)-5-bromo-, 1-(3,5-dibromo-4-hydroxyphenyl)-5-bromo-, and 1-(3,5-dibromo-4-hydroxyphenyl)-5-bromo-6-methyldihydrouracils and 1-(3,5-dibromo-4-hydroxyphenyl)-5-methyluracil. 5-Bromo- and 5,5-dibromodihydrouracils were dehydrobrominated, and the same compounds undergo decomposition to 3,5-dibromo-4-hydroxyphenylurea upon alkaline hydrolysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1251–1254, September, 1982.     

Synthesis and properties of 4-chloromethyl-6-hydroxy-coumarins and 4-(2-benzofuryl)-6-hydroxycoumarins

New 4-chloromethyl-6-hydroxycoumarins have been obtained by the condensation of hydroquinone derivatives with 4-chloroacetoacetic ester, and have been used for the synthesis of 4-(2-benzofuryl)-6-hydroxycoumarins. Alkylation and acylation of the phenolic hydroxyl of the synthesized 4-(2-benzo-furyl)coumarins have been investigated. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 361–369, March, 2009.     

Convenient synthesis of （2S,3R,4R,5S,6R）-2-（3-（4-ethylbenzyl）-4- chlorophenyl）-6-（hydroxymethyl）-tetrahydro- 2H-pyran-3,4,5-triol

A convenient approach for the preparation of （2S,3R,4R,5S,6R）-2-（3-（4-ethylbenzyl）-4-chlorophenyl）-6-（hydroxymethyl）- tetrahydro-2H-pyran-3,4,5-triol I is developed. The target compound via four steps is synthesized from 4-bromo-2-（bromomethyl）- 1-chlorobenzene and the isomers of undesired ortho-products were avoided during the preparation.     

In search of benzene-like Sn6(6-): synthesis of Na4CaSn6 with interconnected cyclohexane-like Sn6(6-)

The title compound was synthesized in an attempt to produce stacked benzene-like Sn6(6-) rings separated by alkaline-earth cations in analogy with the recently reported stacks of aromatic cyclopentadienyl-like Sn5(6-) in Na8BaSn6 (in addition to isolated Sn4- anions). The resulting compound, synthesized from a stoichiometric mixture of the elements at high temperature, has the "correct" stoichiometry with six tin atoms and six positive charges. However, the rings of Sn6(6-) are puckered into chair-type cyclohexanes that are interconnected into isolated cylindrical tubes stuffed with Ca2+ between the rings. Such tubes, if fused to each other, form the hexagonal diamond structure. The new compound is electronically balanced according to magnetic and four-probe resistivity measurements. Reported are also the synthesis and properties of Na10EuSn12 and Na10YbSn12 which are isostructural with the known Na10CaSn12.     

6-溴甲基-2-甲基-3(H)-喹唑啉-4-酮的合成

6-溴甲基-2-甲基-3(H)-喹唑啉-4-酮(见图1所示)是治疗晚期结肠癌和直肠癌的一线药物雷替曲赛(Raltitrexed)[1～3]的重要中间体.Raltitrexed是由英国AstraZeneca公司开发的胸苷酸合成酶抑制剂,已经在全球主要发达国家上市.Raltitrexed可以选择性地抑制胸苷酸合酶(thymidylate synthase,TS),干扰TS正常的生理功能,抑制DNA的合成,进而起到抑制肿瘤细胞生长或增殖的作用[4～5].