2,5‐Bis(methylthio)‐1,4‐benzo­quinone and 2‐methyl‐3‐(methylsulfonyl)benzo[b]thiophene

The structure of 2,5‐bis­(methyl­thio)‐1,4‐benzo­quinone, C₈H₈O₂S₂, is composed of an essentially planar centrosymmetric benzo­quinone substituted with two methyl­thio groups. The important bond distances are S—Csp³ 1.788 (2) and S—Csp² 1.724 (2) Å, and the two Csp²—Csp² distances are 1.447 (3) and 1.504 (3) Å, which differ significantly. There are short S?S interactions of 3.430 (1) Å and Csp²—H?O‐type contacts forming a dimeric motif with graph set R₂²(8). The structure of 2‐methyl‐3‐(methyl­sulfonyl)­benzo­[b]­thio­phene, C₁₀H₁₀O₂S₂, is composed of an essentially planar benzo­thio­phene moiety substituted with methyl and methyl­sulfonyl groups. The mean values of the important bond distances are endocyclic S—Csp² 1.734 (3), S=O 1.434 (4) and C—C_aromatic 1.389 (10) Å. The exocyclic S—Csp² and S—Csp³ distances are 1.759 (4) and 1.763 (5) Å, respectively.     

Swertisin dihydrate

The title compound, 6‐C‐gluco­pyran­osyl‐7‐O‐methyl­apigenin dihydrate, C₂₂H₂₂O₁₀·2H₂O, is a natural C‐glu­cosyl­flavone. The flavone skeleton is almost planar, the dihedral angle between the pyran moiety and the 4‐hydroxy­phenyl ring being 9.8 (3)°. The basal plane of the pyran­osyl ring of the glucose moiety is almost perpendicular to the benzo­pyran ring system. The flavone skeletons are stacked along the a axis, forming layers parallel to (001). Between these hydro­phobic layers, the glucose groups and water mol­ecules of crystallization are connected via O—H⋯O hydrogen bonds, forming hydro­philic layers.     

A second triclinic modification of 2′,6′‐di­methoxy­flavone

Crystals of a second triclinic modification of the title compound, 2‐(2,6‐di­methoxy­phenyl)‐4H‐1‐benzo­pyran‐4‐one, C₁₇H₁₄O₄, were grown from a hot cyclo­hexane solution. In the mol­ecule, the O—C—C—C torsion angle at the junction between the benzo­pyran and phenyl rings is 67.6 (3)°.     

Pomiferin

The crystal structure of pomiferin, 3‐(3,4‐di­hydroxy­phenyl)‐5‐hydroxy‐8,8‐di­methyl‐6‐(3‐methyl­but‐2‐enyl)‐4H,8H‐pyrano[2,3‐h]­chromen‐4‐one, C₂₅H₂₄O₆, has been determined. The benzo­pyran­one ring system is nearly planar and the dihedral angle between the phenyl ring and the benzo­pyran­one moiety is 40.85 (4)°. The crystal structure is stabilized by a one‐dimensional chain of inter‐ and intramolecular O—H⃛O hydrogen bonds, with O⃛O distances in the range 2.5546 (15)–2.7999 (16) Å.     

Two biologically active thio­phene‐3‐carbox­amide derivatives

The compounds 2‐{[(E)‐(4‐methoxy­phenyl)­methyl­ene]­amino}‐N‐(3‐methyl­phenyl)‐4,5,6,7‐tetra­hydro‐1‐benzo­thio­ph­ene‐3‐carbox­amide, C₂₄H₂₄N₂O₂S, (I), and N‐(4‐meth­yl­phenyl)‐2‐{[(E)‐(4‐methyl­phenyl)­methyl­ene]­amino}‐4,5,6,7‐tetra­hydro‐1‐benzo­thio­phene‐3‐carbox­amide, C₂₄H₂₄N₂OS, (II), show antibacterial and antifungal activities. The m‐toluidine ring in (I) and the p‐toluidine ring in (II) are coplanar with their respective thio­phene rings. In (I), an intermolecular C—H⋯O hydrogen bond is present, whereas (II) does not exhibit any significant intermolecular interactions. However, in both compounds, an intramolecular N—H⋯N hydrogen bond forms a pseudo‐six‐membered ring, thus locking the molecular conformation and eliminating conformational flexibility.     

Self‐assembly of 2‐pivaloyl‐6‐chloro­pterin

In the title compound, N‐(6‐chloro‐4‐oxo‐3,4‐di­hydro­pteridin‐2‐yl)­‐2,2‐di­methyl­propan­amide, C₁₁H₁₂ClN₅O₂, the rings in the pterin moiety are planar. The amide carbonyl O atom is in syn‐periplanar conformation while the C—N—C—C propanamide linkage is antiperiplanar. The N—H?N and N—H?O intermolecular hydrogen bonds transform the mol­ecules into infinite chains.     

C—H⋯O,C—H⋯π and π–π inter­actions in three benzofuran‐2‐yl ketone derivatives

The mol­ecules of 2‐benzoyl‐1‐benzofuran, C₁₅H₁₀O₂, (I), inter­act through double C—H⋯O hydrogen bonds, forming dimers that are further linked by C—H⋯O, C—H⋯π and π–π inter­actions, resulting in a three‐dimensional supramolecular network. The dihedral angle between the benzo­yl and benzofuran fragments in (I) is 46.15 (3)°. The mol­ecules of bis­(5‐bromo‐1‐benzofuran‐2‐yl) ketone, C₁₇H₈Br₂O₃, (II), exhibit C₂ symmetry, with the carbon­yl group (C=O) lying along the twofold rotation axis, and are linked by a combination of C—H⋯O and C—H⋯π inter­actions and Br⋯Br contacts to form sheets. The stability of the mol­ecular packing in 3‐mesit­yl‐3‐methyl­cyclo­but­yl 3‐methyl­naphtho[1,2‐b]furan‐2‐yl ketone, C₂₈H₂₈O₂, (III), arises from C—H⋯π and π–π stacking inter­actions. The fused naphthofuran moiety in (III) is essentially planar and makes a dihedral angle of 81.61 (3)° with the mean plane of the trimethyl­benzene ring.     

(±)‐(4‐Oxo‐4H‐chromen‐2‐yl)(phenyl)methyl acetate

The title compound, C₁₈H₁₄O₄, forms a supramolecular structure viaπ–π stacking and weak C—H⋯O and C—H⋯π interactions. The benzo­pyran moiety is almost planar. The benzene ring of the phenyl­methyl acetate substituent is nearly perpendicular to the fused benzene and pyran rings and also to the methyl acetate group.     

A 1:1 adduct of hexa­methylene­tetramine and 4‐hydroxy‐3‐methoxy­benz­aldehyde

In the title complex, C₆H₁₂N₄·C₈H₈O₃, the hexa­methyl­ene­tetramine mol­ecule accepts a single intermolecular O—H?N hydrogen bond from the hydroxy group of the 4‐hydroxy‐3‐methoxy­benz­aldehyde moiety. The non‐centrosymmetric crystal structure is built from alternating molecular sheets of 4‐hydroxy‐3‐methoxy­benz­aldehyde and hexa­methyl­ene­tetramine mol­ecules, and is stabilized by intermolecular O—H?N, C—H?O and C—H?π interactions.     

Charge‐transfer complexes of 4‐(di­methyl­amino)­pyridine with 2,4‐, 3,4‐ and 3,5‐di­nitro­benzoic acid

In the three title crystal structures 4‐(di­methyl­amino)­pyridinium 2,4‐di­nitro­benzoate, (I), 4‐(di­methyl­amino)­pyri­dinium 3,4‐di­nitro­benzo­ate, (II), and 4‐(di­methyl­amino)pyri­din­ium 3,5‐di­nitro­benzo­ate, (III), all C₇H₁₁N₂⁺·C₇H₃N₂O₆^?, the ions are connected by an N—H?O hydrogen bond. Dihedral angles between the pyridine and phenyl rings are 69.9 (1), 26.7 (1) and 56.2 (1)° in (I), (II) and (III), respectively. Donor–acceptor π–π stacking is observed in (II) and (III), but not in (I).     

Rotenone α‐oxime

The structure determination of the title compound, rotenone α‐oxime [systematic name: 1,2,12,12a‐tetra­hydro‐8,9‐di­meth­oxy‐2‐(1‐methyl­ethenyl)‐[1]­benzo­py­rano­[3,4‐b]­furo­[2,3‐h][1]benzo­pyran‐6(6H)‐one oxime], C₂₃H₂₃NO₆, confirms that the mol­ecule has an approximately V‐shaped structure. One of the rings has a typical cyclo­hexene‐like monoplanar conformation and the central ring adopts a 1,2‐diplanar conformation.     

4‐(Trifluoromethyl)benzonitrile

4‐(Tri­fluoro­methyl)­benzo­nitrile, C₈H₄F₃N, at 123 K contains mol­ecules linked together through one C—H?F bond and two C—H?N hydrogen bonds into sheets that are further crosslinked to form a dense two‐dimensional network without π?π ring interactions. The aromatic ring is slightly deformed due to the two para‐related electronegative groups.     

Three 1,2,4‐triazole derivatives containing subtituted benzyl and benzyl­amino groups

The title compounds, 4‐benzyl­amino‐3‐(4‐methyl­benzyl)‐1H‐1,2,4‐triazol‐5(4H)‐one, C₁₇H₁₈N₄O, (I), 3‐(4‐methyl­benzyl)‐4‐(4‐methyl­benzyl­amino)‐1H‐1,2,4‐tri­azol‐5(4H)‐one, C₁₈H₂₀N₄O, (II), and 3‐(4‐chloro­benzyl)‐4‐(4‐methyl­benzyl­amino)‐1H‐1,2,4‐triazol‐5(4H)‐one, C₁₇H₁₇ClN₄O, (III), were obtained from the corresponding Schiff base in the presence of diglyme and NaBH₄. Each compound contains a 1,2,4‐triazole ring and two benzene rings, which are essentially planar. The molecules are linked by a combination of intermolecular N—H⋯O and N—H⋯N hydrogen bonds. Additionally, there is a weak π–π stacking interaction in (I), involving the benzene ring of the amino­benzyl group and the partially aromatic 1,2,4‐triazole moiety, with a centroid–centroid distance of 3.7397 (10) Å.     

4,7‐Bis(4‐pyridyl­ethynyl)‐2,1,3‐benzo­thia­diazo­le and its dipyridinium diperchlorate

The title compound, C₂₀H₁₀N₄S, and its dipyridinium salt, 4,4′‐(2,1,3‐benzo­diazol‐4,7‐diyl­diethynyl)­dipyridinium diperchlorate, C₂₀H₁₂N₄S²⁺·2ClO₄^?, display bond alternation in the 2,1,3‐benzo­thia­diazo­le rings, which suggests their quinonoid character. The dipyridinium dication mol­ecules stack along the a axis and form a dimer with short S?N interheteroatom contacts [3.146 (4) Å] between the two 1,2,5‐thia­diazo­le rings. The dimer is surrounded by the perchlorate anions with which it forms a large number of intermolecular N—H?O and C—H?O hydrogen bonds.     

A novel class of fused heterocycles,benzo­[b]­furo­[2,3‐c]­pyrroles

In the isomeric compounds 2‐benzyl‐3‐methyl‐1‐phenyl­benzo­[b]­furo­[2,3‐c]­pyrrole and 2‐benzyl‐1‐methyl‐3‐phenyl­benzo­[b]­furo­[2,3‐c]­pyrrole, both C₂₄H₁₉NO, the pyrrole ring, although presumably somewhat strained, does not differ appreciably from N‐methyl­pyrrole except for a relatively short C—C single bond in the pyrrole ring.     

Hydro­gen‐bonded dimers in N‐(2‐nitro­phenyl­thio)­saccharin

In the title compound, 2‐(2‐nitro­phenyl­thio)‐1,2‐benzo­thia­zol‐3(2H)‐one 1,1‐dioxide, 2‐O₂NC₆H₄S(C₇H₄NO₃S) or C₁₃H₈N₂­O₅S₂, the planes of the saccharin and nitro­phenyl­thiol­ate portions are almost orthogonal. The mol­ecules are linked by C—H?O=S hydrogen bonds [C?O 3.308 (3) Å, H?O 2.44 Å and C—H?O 155°] into cyclic centrosymmetric R²₂(16) dimers, reinforced by aromatic π?π stacking interactions between the nitrated aryl rings.     

A chiral furocoumarin

The furocoumarin 1,2‐di­hydro‐2‐(1,2‐di­hydroxy­prop‐2‐yl)‐8H‐furo­[2,3‐h]­benzo­pyran‐8‐one crystallizes from methanol–water as the monohydrate C₁₄H₁₄O₅·H₂O. Both chiral centers have the S configuration. Both OH groups and both H atoms of the water mol­ecule form intermolecular hydrogen bonds with O?O distances in the range 2.7686 (18)–2.8717 (18) Å.     

2‐(2‐Naphthyl­oxy)­acetate derivatives. II. A new class of antiamnesic agents

The title compounds, 4‐(2‐naphthyl­oxy­methyl­carbonyl)­morpholine, C₁₆H₁₇NO₃, (I), and 4‐methyl‐1‐(2‐naphthyl­oxy­methyl­carbonyl)­piper­azine, C₁₇H₂₀N₂O₂, (II), are potential antiamnesics. The morpholine ring in (I) and the piperazine ring in (II) adopt chair conformations. In (I), the mol­ecules are linked by weak intermolecular C—H⃛O interactions into chains that have a graph‐set motif of C(10), while in (II), the mol­ecules are linked by weak intermolecular C—H⃛O interactions that generate two C(7) graph‐set motifs. The dihedral angle between the naphthalene moiety and the best plane through the morpholine ring is 20.62 (4)° in (I), while the naphthalene moiety is oriented nearly perpendicular to the mean plane of the piperazine ring in (II).     

A mixed crystal of imperatorin and phellopterin,with C—H...O,C—H...π and π–π interactions

The crystal structure of 9‐(3‐methyl­but‐2‐enyl­oxy)­‐7H‐furo­[3,2‐g]­chro­men‐7‐one–4‐methoxy‐9‐(3‐methyl­but‐2‐enyl­oxy)‐7H‐­furo­[3,2‐g]­chromen‐7‐one (0.926/0.074), 0.926C₁₆H₁₄O₄·0.074C₁₇H₁₆O₅, is characterized by two independent imperatorin mol­ecules in the asymmetric unit, which exhibit different side‐chain conformations. A small amount of phellopterin overlaps with one of the two imperatorin mol­ecules. The supramol­ecular structure is supported by C—H...O, C—H...π and π–π interactions.     

Ethyl β‐{2‐[4‐(dimethylamino)phenyliminomethyl]‐1‐(phenylsulfonyl)indol‐3‐yl}acrylate

The title compound, C₂₈H₂₇N₃O₄S, crystallizes in the centrosymmetric space group P2₁/n, with one mol­ecule in the asymmetric unit. In the indole ring, the dihedral angle between the fused rings is 3.6 (1)°. The phenyl ring of the sulfonyl substituent makes a dihedral angle of 79.2 (1)° with the best plane of the indole moiety. The phenyl ring of the di­methyl­amino­phenyl group is orthogonal to the phenyl ring of the phenyl­sulfonyl group. The dihedral angle formed by the weighted least‐squares planes through the pyrrole ring and the phenyl ring of the di­methyl­amino­phenyl group is 7.8 (1)°. The molecular structure is stabilized by C—H?O and C—H?N interactions.