(2E)-3-(6-methoxynaphthalen-2-yl)-1-(pyridin-3-yl)prop-2-en-1-one and its cyclocondensation product with guanidine, (4RS)-2-amino-4-(6-methoxynaphthalen-2-yl)-6-(pyridin-3-yl)-3,4-dihydropyrimidine monohydrate: two types of hydrogen-bonded sheet

4-Styrylquinolines from cyclocondensation reactions between (2-aminophenyl)chalcones and 1,3-diketones: crystal structures and regiochemistry

Structures are reported for two matched sets of substituted 4-styrylquinolines which were prepared by the formation of the heterocyclic ring in cyclocondensation reactions between 1-(2-aminophenyl)-3-arylprop-2-en-1-ones with 1,3-dicarbonyl compounds. (E)-3-Acetyl-4-[2-(4-methoxyphenyl)ethenyl]-2-methylquinoline, C21H19NO2, (I), (E)-3-acetyl-4-[2-(4-bromophenyl)ethenyl]-2-methylquinoline, C20H16BrNO, (II), and (E)-3-acetyl-2-methyl-4-{2-[4-(trifluoromethyl)phenyl]ethenyl}quinoline, C21H16F3NO, (III), are isomorphous and in each structure the molecules are linked by a single C-H...O hydrogen bond to form C(6) chains. In (I), but not in (II) or (III), this is augmented by a C-H...π(arene) hydrogen bond to form a chain of rings; hence, (I)-(III) are not strictly isostructural. By contrast with (I)-(III), no two of ethyl (E)-4-[2-(4-methoxyphenyl)ethenyl]-2-methylquinoline-3-carboxylate, C22H21NO3, (IV), ethyl (E)-4-[2-(4-bromophenyl)ethenyl]-2-methylquinoline-3-carboxylate, C21H18BrNO2, (V), and ethyl (E)-2-methyl-4-{2-[4-(trifluoromethyl)phenyl]ethenyl}quinoline-3-carboxylate, C22H18F3NO2, (VI), are isomorphous. The molecules of (IV) are linked by a single C-H...O hydrogen bond to form C(13) chains, but cyclic centrosymmetric dimers are formed in both (V) and (VI). The dimer in (V) contains a C-H...π(pyridyl) hydrogen bond, while that in (VI) contains two independent C-H...O hydrogen bonds. Comparisons are made with some related structures, and both the regiochemistry and the mechanism of the heterocyclic ring formation are discussed.

Three closely related 1-(naphthalen-2-yl)prop-2-en-1-ones: pseudosymmetry, disorder and supramoleular assembly mediated by C-H...π and C-Br...π interactions

It has been observed that when electron-rich naphthyl rings are present in chalcones they can participate in π-π stacking interactions, and this can play an important role in orientating inhibitors within the active sites of enzymes, while chalcones containing heterocyclic substituents additionally exhibit fungistatic and fungicidal properties. With these considerations in mind, three new chalcones containing 2-naphthyl substituents were prepared. 3-(4-Fluorophenyl)-1-(naphthalen-2-yl)prop-2-en-1-one, C₁₉H₁₃FO, (I), crystallizes with Z' = 2 in the space group P-1 and the four molecules in the unit cell adopt an arrangement which resembles that in the space group P2₁/a. Although 3-(4-bromophenyl)-1-(naphthalen-2-yl)prop-2-en-1-one, C₁₉H₁₃BrO, (II), with Z' = 1, is not isostructural with (I), the molecules of (I) and (II) adopt very similar conformations. In 1-(naphthalen-2-yl)-3-(thiophen-2-yl)prop-2-en-1-one, C₁₇H₁₂OS, (III), the thiophene unit is disordered over two sets of atomic sites, with occupancies of 0.780 (3) and 0.220 (3), which are related by a near 180° rotation of the thiophene unit about its exocyclic C-C bond. The molecules of compound (I) are linked by three independent C-H...π(arene) hydrogen bonds to form centrosymmetric octamolecular aggregates, whereas the molecules of compound (II) are linked into molecular ladders by a combination of C-H...π(arene) and C-Br...π(arene) interactions, and those of compound (III) are linked into centrosymmetric dimers by C-H...π(thiophene) interactions.

The crystal structures of two chalcones: (2E)-1-(5-chloro-thio-phen-2-yl)-3-(2-methyl-phen-yl)prop-2-en-1-one and (2E)-1-(anthracen-9-yl)-3-[4-(propan-2-yl)phen-yl]prop-2-en-1-one

In the crystal of compound (I), C14H11ClOS, mol-ecules are linked by C-H⋯O hydrogen bonds to form simple C(5) chains. Compound (II), C26H22O, crystallizes with Z' = 2 in space group P-1; one of the mol-ecules is fully ordered but the other is disordered over two sets of atomic sites having occupancies 0.644 (3) and 0.356 (3). The two disordered components differ from one another in the orientation of the isopropyl substituents, and both differ from the ordered mol-ecules in the arrangement of the central propenone spacer unit, so that the crystal of (II) contains three distinct conformers. The ordered and disordered conformers each form a C(8) chain built from a single type of C-H⋯O hydrogen bond but those formed by the disordered conformers differ from that formed by the ordered form.