1-Benzoyl-3-methyl-2,6-diphenyl-4-piperidone

In the title moleclue, C25H23NO2, the 4-piperidone ring adopts a boat conformation. The molecular conformation is stabilized by an intramolecular C-H center dot center dot center dot O hydrogen bond. In the crystal, molecules are connected through weak intermolecular C-H center dot center dot center dot O hydrogen bonds.

Chiral Synthons from Monoterpenes.1 Stereoselective Syntheses of (-)5S, 6S, 9R-6-Isopropyl-9-Methyl-2-Oxaspiro[4.4]Nonan-3-One and (-) 3aR, 6R, 7aR-3a-Methyl-6-Isopropenylhexahydrobenzofuran-2-One

Highly stereoselective syntheses of two C-12 chiral synthons 3 and 9, mentioned in the title, starting from the monoterpenes R-1 imonene and R-carvone, using radical cyc 1 sation as key reaction, are described.

1-(2-Chloroacetyl)-3-methyl-2,6-diphenylpiperidin-4-one

The asymmetric unit of the title compound, C20H20ClNO2, contains two crystallographically independent molecules of similar geometry. The piperidine ring adopts a distorted boat conformation in both molecules, in which the N atom assumes an almost planar configuration.

Ethyl 6-chloro-2-methyl-4-phenylquinoline-3-carboxylate

In the title compound, C19H16ClNO2, the quinoline ring system is planar (r.m.s. deviation = 0.008 angstrom). The phenyl group and the -CO2 fragment of the ester unit form dihedral angles of 60.0 (1) and 60.5 (1)degrees, respectively, with the quinoline ring system.

3-Benzyl-6-benzylamino-1-methyl-5-nitro-1,2,3,4-tetrahydropyrimidine

In the title compound, C19H22N4O2, the tetrahydropyrimidine ring adopts an envelope conformation (with the N atom connected to the benzyl group representing the flap). This benzyl group occupies a quasi-axial position. The two benzyl groups lie over the tetrahydropyridimidine ring. The amino group is a hydrogen-bond donor to the nitro group.

Crystal And Molecular-Structure Of 8-Acetoxy-6-(2,4-Dimethoxy-5-Bromophenyl)-3-Methyl-Tricyclo[5,2,1,03,8 ]Decan-2-One

The crystal and molecular structure has been determined by the heavy-atom method and refined by the least-squares procedure to R= 8"3 % for 2033 photographically observed reflexions. The compound crystallizes in the space group P]" with two molecules in a unit cell of dimensions a = 11"68 + 0-02, b = 12"91 +0"02, c= 10"43+0"02/~, e= 114"7+ 1, fl=90-2+ 1 and 7,= 118.3+ 1 °. The unit cell also contains one molecule of the solvent, benzene. The 'cage' part of the molecule exhibits a large number of elongated bonds and strained internal valency angles. The bridgehead angle in the bicyclic heptane ring system is 89 °. The acetate group at C(16) and the methyl group at C(15) are cis to each other.

Crystal structure and conformation study of N-methyl-t-3-methyl-r-2, c-6-diphenylpiperidin-4-one thiosemicarbazone

Thiosemicarbazones are having the ability to bind with metal and inhibit the enzyme ribonucleoside diphosphate reductase(RDR),an enzyme which is involved in the synthesis of DNA precursors in the mammalian cells.The title compound N-methyl-t-3-methyl-r-2, c-6-diphenylpiperidin-4-one thiosemicarbazone (NMMDPT), CCDC 218052, was prepared using Mannich reaction and characterized by X-ray diffraction methods.The crystal data are:C20H24N4S; M.W= 352.49, triclinic,space group P (1) over bar, a = 8.467(2)angstrom, b = 10.228(2)angstrom, c = 12.249(2)angstrom; lpha=92.595(3)degrees, beta=104.173(3)degrees, gamma=13.628(3)degrees; V=930.0(3)angstrom(3), Z=2, D-cal=1.259Mgm(-3),mu=0.184mm(-1),lambda (MoKalpha)=0.71073 angstrom, final R1 and wR2 are 0.0470 and 0.1052, respectively. The piperidine rings adopt chair conformation. The planar phenyl rings are oriented equatorially at 2,6-positions of the piperidine ring. The molecular packing can be viewed as dimers held together by two N-H...S types of intermolecular hydrogen bonds. Weak C-H...pi interactions also support the stability of the molecules in the crystal in addition to van der Waals forces. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

1,3-Dimethyl-2,6-diphenylpiperidin-4-one

In the title moleclue, C19H21NO, the 4-piperidone ring adopts a chair conformation in which the two benzene rings and the methyl group attached to C atoms all have equatorial orientations. In the crystal structure, centrosymmetric dimers are formed through weak intermolecular C-H center dot center dot center dot O hydrogen bonds [the dihedral angle between the aromatic rings is 58.51 (5)degrees].

3-Ethyl-4-methyl-1H-pyrazol-2-ium-5-olate

The title compound, C(6)H(10)N(2)O, is a zwitterionic pyrazole derivative. The crystal packing is predominantly governed by a three-center iminium-amine N(+)-H center dot center dot center dot O(-)center dot center dot center dot H-N interaction, leading to an undulating sheet-like structure lying parallel to (100).

Unusual photodimerization of 7-fluoro-4-methylcoumarin and 6-fluoro-4-methylcoumarin in the solid state

Photodimerization of 7-fluoro-4-methylcoumarin 1 is topochemical while 6-fluoro-4-methylcoumarin 2 does not lead to the expected product based on the topochemical principles. Compound 1 yield an anti-MT photodimer with a lower dimer conversion while compound 2 results in a syn-HH photodimer. The packing features of 1, 2 and 2a (the photodimer of 2) have been unequivocally established by single crystal X-ray diffraction studies. The rationale for the significant lower dimer conversion in 1 is provided. The defect induced dimerization reaction in 2 as a function of temperature is analyzed which verifies that the reaction proceeds with an induction period. The details of the interactions involving fluorine are analyzed.

New structural insights and molecular-modelling studies of 4-methyl-5-beta-hydroxyethylthiazole kinase from Pyrococcus horikoshii OT3 (PhThiK)

4-Methyl-5-beta-hydroxyethylthiazole kinase (ThiK) catalyses the phosphorylation of the hydroxyl group of 4-methyl-5-beta-hydroxyethylthiazole. This work reports the first crystal structure of an archaeal ThiK: that from Pyrococcus horikoshii OT3 (PhThiK) at 1.85 angstrom resolution with a phosphate ion occupying the position of the beta-phosphate of the nucleotide. The topology of this enzyme shows the typical ribokinase fold of an alpha/beta protein. The overall structure of PhThiK is similar to those of Bacillus subtilis ThiK (BsThiK) and Enterococcus faecalis V583 ThiK (EfThiK). Sequence analysis of ThiK enzymes from various sources indicated that three-quarters of the residues involved in interfacial regions are conserved. It also revealed that the amino-acid residues in the nucleotide-binding, magnesium ion-binding and substrate-binding sites are conserved. Binding of the nucleotide and substrate to the ThiK enzyme do not influence the quaternary association (trimer) as revealed by the crystal structure of PhThiK.

Ethyl 2,6-dichloro-4-phenylquinoline-3-carboxylate

In the title compound,C18H13Cl2NO2,the quinoline ring system is almost planar (r.m.s.deviation 0.009 angstrom), and the phenyl and carboxylate planes are twisted away from it by 59.2 (1)and 65.9 (2)degrees,respectively.