Design,Synthesis, and Bioactivity Evaluation of Novel 3‐(Substituted Phenoxy)‐6‐Methyl‐4‐(3‐Trifluoromethylphenyl) Pyridazine Derivatives

Using 3‐(4‐cyano phenoxy)‐6‐methyl‐4‐(3‐trifluoromethylphenyl) pyridazine (compound A ) as a leading compound, a total of 24 novel 3‐(substituted phenoxy)‐6‐methyl‐4‐(3‐trifluoromethylphenyl) pyridazine derivatives containing two electron‐withdrawing groups on the benzene ring (acylamine and oxime ether) were synthesized. Their herbicidal, insecticidal activities were bioassayed, and the herbicidal activity of compound CD-2 against Brassica campestris was 97.6% at 300 g/ha, which was better than the commercial herbicide diflufenican at the this concentration and is equal to the activity of the leading compound A . Compound CD-4 , CD-5 , CJ-3 , and CJ-5 displayed excellent insecticidal activity against Aphis laburni Kaltenbach (>95%). The results show that the oxime ether substitutions exhibit better bleaching and herbicidal activity than the acylamine ones. The bleaching and herbicidal activity of para‐position substitutions is better than the meta‐position ones. It seems that the para‐position on the benzene ring of oxime ether pyridazine derivatives is one of the key active sites that affect their herbicidal activities.     

Phenyl‐(2‐pyridyl)‐(3‐pyridyl)‐(4‐pyridyl)methane: Synthesis,Chiroptical Properties,and Theoretical Calculation of Its Absolute Configuration

The title compound, a prototypical chiral molecule based on a tetraarylmethane framework, has been synthesized in five steps from (2‐pyridyl)‐(3‐pyridyl)ketone. X‐ray crystallographic analysis revealed the tetraarylmethane framework of the molecule but did not determine the positions of the nitrogen atoms because the crystal is a racemic compound and the aryl groups are disordered in the crystal. The optical resolution of the title compound was achieved by chiral HPLC with a Chiralcel OD column. The CD spectra of the two fractions in acetonitrile exhibited opposite signs as expected for a pair of enantiomers. Their CD spectra are changed in 2 M HCl due to protonation. The calculated CD curve for the target molecule based on time‐dependent density functional theory (TDDFT) reproduces the experimental result very well, thus suggesting that the first eluted fraction is the R isomer in terms of absolute configuration.     

Antibacterial and Antifungal Activities of 2‐(substituted ether)‐5‐(1‐phenyl‐5‐(trifluoromethyl)‐1H‐pyrazol‐4‐yl)‐1,3,4‐oxadiazole Derivatives

By replacing the amide bond into 1,3,4‐oxadiazole moiety, a series of 1‐phenyl‐5‐(trifluoromethyl)‐1H‐pyrazole derivatives bearing 1,3,4‐oxadiazole were synthesized and evaluated their antibacterial and antifungal activity. The bioassay results revealed that compounds 7a and 7b showed the strongest antibacterial activity toward pathogen Xanthomonas oryzae pv. oryzae with the EC50 values of 15.0 and 6.4 µg/mL, respectively; compound 6a exhibited comprehensive antifungal activity toward six kinds of fungi; compound 6f could selectively inhibit the growth of Sclertinia sclerotiorum and Rhizoctonia solani with the inhibition rates of 82.5 and 80.3% at the concentrate of 100 µg/mL, respectively; compound 7b exerted good antifungal activity toward Fusarium oxysporum, Cytospora mandshurica, and Rhizoctonia solani with the inhibition rates of 70.8, 69.5, and 71.5%, respectively. The results suggested that this kind of compounds could be further studied as promising antimicrobial agents.     

Synthesis of 2‐(3‐indolyl)‐1,4‐naphthoquinones using 3‐iodoindoles

The usefulness of 3‐iodoindoles available for introduction of an indole unit is presented. The reaction of various halo‐3‐iodoindoles with 1,4‐naphthoquinone gave the corresponding 2‐(3‐indolyl)‐1‐4,naphthoquinones in moderate yields. The 3‐iodoindole was used for synthesis of a compound containing both naph‐thazarin and indole skeletons.     

N‐(3‐Phenoxy‐4‐pyridinio)methanesulfonamidate

The title compound, C₁₂H₁₂N₂O₃S, is a strict pyridine analogue of nimesulide, a selective inhibitor of cyclooxygen­ase‐2. The structure is characterized by a pyridinium ring with a deprotonated sulfon­amide group. An intermolecular charge‐assisted hydrogen bond between these two groups is observed within the crystal packing, linking the mol­ecules into an infinite chain running along the b‐axis direction.     

Design and Synthesis of Novel 3‐(Phenyl)‐2‐(3‐substituted propylthio) Quinazolin‐4‐(3H)‐ones as a New Class of H1‐Antihistaminic Agents

A series of novel 3‐(phenyl)‐2‐(3‐substituted propylthio) quinazolin‐4‐(3H)‐ones were synthesized by the reaction of 2‐(3‐bromopropylthio)‐3‐(phenyl) quinazolin‐4‐(3H)‐one with various amines. The starting material, 2‐(3‐bromopropylthio)‐3‐(phenyl) quinazolin‐4‐(3H)‐one was synthesized from aniline. When tested for their in vivo H₁‐antihistaminic activity on conscious guinea pigs, all the test compounds protected the animals from histamine‐induced bronchospasm significantly. Compound 2‐(3‐(4‐methylpiperazin‐1‐yl) propylthiothio)‐3‐(phenyl) quinazolin‐4(3H)‐one ( Ph5 ) emerged as the most active compound (73.23% protection) of the series when compared with the reference standard chlorpheniramine maleate (70.09% protection). Compound Ph5 shows negligible sedation (5.01 %) compared with chlorpheniramine maleate (29.58%). Therefore, compound Ph5 can serve as the leading molecule for further development into a new class of H₁‐antihistaminic agents.     

Synthetic Applications of 3‐(Phenylsulfinyl)‐3‐sulfolene

The title compound 2 was readily prepared by MCPBA oxidation of the sulfide 1. Thermal desulfonylation of 2 gave the sulfoxide‐substituted diene 3. The Diels‐Alder reactions of 3 with various dienophiles gave the cyclized products 4‐9 in good yields. The regiochemistry was found to be dominated by the phenylsulfinyl group, but could be reversed by the presence of a Lewis acid. Deprotonation of 2 by BuLi, followed by the reaction with alkyl halides, gave the substituted 2‐sulfolenes 10. A synthetic application of 10 was demonstrated by converting 10e to the bicyclic product 11.     

2‐[(E)‐(4‐Hydroxy‐3‐methoxybenzylidene)amino]‐N‐(2‐methylphenyl)‐4,5,6,7‐tetrahydro‐1‐benzothiophene‐3‐carboxamide

The title compound, C₂₄H₂₄N₂O₃S, exhibits antifungal and antibacterial properties. The compound crystallizes with two molecules in the asymmetric unit, with one molecule exhibiting `orientational disorder' in the crystal structure with respect to the cyclohexene ring. The o‐toluidine groups in both molecules are noncoplanar with the respective cyclohexene‐fused thiophene ring. In both molecules, there is an intramolecular N—H...N hydrogen bond forming a pseudo‐six‐membered ring which locks the molecular conformation and eliminates conformational flexibility. The crystal structure is stabilized by O—H...O hydrogen bonds; both molecules in the asymmetric unit form independent chains, each such chain consisting of alternating `ordered' and `disordered' molecules in the crystal lattice.     

(Z)‐3‐(1‐Methyl‐1H‐indol‐3‐yl)‐2‐(thio­phen‐3‐yl)­acrylo­nitrile

The title compound, C₁₆H₁₂N₂S, has been synthesized by base‐catalyzed condensation of 1‐methyl­indole‐3‐carbox­aldehyde with thio­phene‐3‐aceto­nitrile. The product assumes an approx­imately planar Z configuration. The mol­ecule has a thienyl‐ring flip disorder.     

1‐(Thiophen‐3‐yl)ethanone

The structure of the title compound, C₆H₆OS, exhibits a flip‐type disorder of the thiophene ring [occupancy ratio = 0.848 (3):0.152 (3)], which is typical for many thiophene derivatives. The puckered thiophene ring is essentially coplanar with the plane formed by the non‐H atoms of the acetyl substituent, similar to its simple analogues, i.e. 3‐acetyl‐2‐carboxythiophene, 4‐acetyl‐3‐carboxythiophene and 3,5‐diacetyl‐2‐ethylamino‐4‐methylthiophene. In the crystal structure, molecules are connected by C—H...π hydrogen bonds, forming a sheet parallel to the (001) plane. Moreover, an inspection of the crystal lattice reveals that there are short S...O contacts connecting the molecules of adjacent sheets. Comparison of the title crystal structure with its simple 3‐methoxythiophene analogue shows a close similarity in the herringbone arrangement of molecules and in the presence of C—H...π interactions and S...O contacts.     

[1,1,2,2‐(CO)4‐1,2‐μ‐(CO)‐4,11‐(SMe2)2‐closo‐1,2‐Co2B10H8]

The title compound, 1,1,2,2‐tetra­carbonyl‐1,2‐μ‐carbonyl‐4,11‐di­methyl­sulfido‐closo‐1,2‐dicobaltadodecaborane, [Co₂(C₄H₂₀B₁₀S₂)(CO)₅], has a closo 12‐vertex {1,2‐Co₂B₁₀H₈} structure with SMe₂ ligands at the exo‐4‐ and 11‐positions. The cluster displays close structural similarities to the SEt₂ analogue.     

2‐(3‐tert‐Butyldimethylsiloxy‐4‐methoxyphenyl)‐6‐methoxy‐3‐(3,4,5‐trimethoxybenzoyl)indole

In the crystal structure of the title compound, C₃₂H₃₉NO₇Si, all geometric parameters fall within experimental error of expected values. The analysis of molecular‐packing plots reveals an infinite two‐dimensional linear array running parallel to the b axis, formed by one N—H?O intermolecular hydrogen‐bonding interaction. Several potential C—H?O interactions are also present.     

A Convenient Synthesis of 6,8-Dimethoxy-3-[（2-（4-methoxyphenyl）ethyl）isocoumarin

6,8-Dimethoxy-3-[2-（4-methoxyphenyl）ethyl]isocoumarin was synthesized by condensation of 5,7-dimethoxyhompophthalic acid with 3-（4-methoxyphenyl）propanoyl chloride. The structure of the synthesized compound was confirmed by its mass spectrometric studies. The synthesized compound serves as a model for synthesis of DL-agrimonolide.     

Ethyl (E)‐3‐(2‐hydroxy­phenyl)‐2‐(morpholino­carbonyl)­propenoate

The title compound, C₁₆H₁₉NO₅, crystallizes as a centrosymmetric dimer through strong O—H⋯O hydrogen‐bonding interactions between the hydroxy­phenyl and morpholino­carbonyl groups. The morpholino­carbonyl group is almost perpendicular to the propenoate moiety. Electron delocalization in the N—C(=O) fragment leads to the formation of hydrogen‐bonded S(5) ring motifs through C—H⋯O interactions.     

rac‐(Z)‐2‐(2‐Thienylmethylene)‐1‐azabicyclo[2.2.2]octan‐3‐ol

The asymmetric unit of the racemic form of the title compound, C₁₂H₁₅NOS, contains four crystallographically independent molecules. The olefinic bond connecting the 2‐thienyl and 1‐azabicyclo[2.2.2]octan‐3‐ol moieties has Z geometry. Strong hydrogen bonding occurs in a directed co‐operative O—H...O—H...O—H...O—H R₄⁴(8) pattern that influences the conformation of the molecules. Co‐operative C—H...π interactions between thienyl rings are also present. The average dihedral angle between adjacent thienyl rings is 87.09 (4)°.     

6‐(2‐Hydro­xy­benzoyl)‐5‐(pyrrol‐2‐yl)‐3H‐pyrrolizine

The title compound, 2‐hydroxy­phenyl 5‐(pyrrol‐2‐yl)‐3H‐pyrrolizin‐6‐yl ketone, C₁₈H₁₄N₂O₂, was isolated from the base‐catalyzed 1:2 condensation of 2‐hydroxy­aceto­phenone with pyrrole‐2‐carbaldehyde. The pyrrole N—H and hydroxy­benzoyl O—H groups are hydrogen bonded to the benzoyl O atom. The allyl­ic C=C double bond of the 3H‐pyrrolizine system is located between ring positions 1 and 2, the C atom at position 3 (adjacent to the N atom) being single bonded.     

4‐(4‐Chloro­phen­yl)‐3‐(4‐phenyl­pent‐4‐en­yloxy)‐1,3‐thia­zole‐2(3H)‐thione

The title compound, C₂₀H₁₈ClNOS₂, is a thia­zole‐derived thio­hydroxamic acid O‐ester. The value of Z′ is 3 and the asymmetric unit comprises three mol­ecules of identical helicity along the N—O bond. Two of these show an anti and the third a syn arrangement of substituents attached in positions 3 and 4 to the 1,3‐thia­zole nucleus.     

3β‐(1‐Allyl‐1‐pyrrolidinio)‐16‐(2‐pyridylmethylene)androst‐5‐en‐17β‐ol bromide hemihydrate

The title compound, C₃₂H₄₅N₂O⁺·Br^?·0.5H₂O, has the outer two six‐membered rings in chair conformations, while the central ring is in an 8β,9α‐half‐chair conformation. The five‐mem­bered ring of the steroid nucleus adopts a slightly deformed 14α‐envelope conformation. The pyridyl­methyl­ene moiety has an E configuration with respect to the hydroxyl group at position 17. The structure is stabilized by a network of O—H?Br‐type intermolecular hydrogen bonds.     

Syntheses of 1‐(4‐methylsulfonylphenyl)‐5‐aryl‐1,2,3‐triazoles and ‐(4‐aminosulfonylphenyl)‐5‐aryl‐1,2,3‐triazoles

Condensation of 4‐methylsulfonylaniline with aryl aldehyde in ethanol‐tetrahydrofuran afforded the imino compound 3 . 1,3‐Cycloaddtion of diazomethane with compound 3 followed by oxidazation of the triazoline 4 with potassium permanganate gave 1‐(4‐methylsulfonylphenyl)‐5‐aryl‐1,2,3‐triazoles 5 . Similarly, condensation of 4‐(N,N‐dibenzylaminosulfonyl)aniline with aryl aldehyde followed by 1,3‐cycloaddition of diazomethane with the imino compound 11 and the subsequent oxidation of triazoline 12 with potassium permanganate yielded the triazole 13 . Debenzylation of compound 13 with sulfuric acid gave the desired compound 1‐(4‐aminosulfonylphenyl)5‐aryl‐1,2,3‐triazoles 14 .     

N‐(4‐Cyano­phenyl)‐α‐(4‐methoxy­phenyl)­nitro­ne

In the crystal structure of the title compound, 4‐cyano‐N‐(4‐methoxy­benzyl­idene)­phenyl­amine N‐oxide, C₁₅H₁₂N₂O₂, the 4‐methoxy­phenyl is approximately coplanar with the nitrone moiety but significantly rotated with respect to the 4‐cyano­phenyl moiety. The extent of this rotation is significantly different for the two crystallographically independent mol­ecules of the asymmetric unit [dihedral angles of 19.4 (1) and 26.5 (1)°]. The geometry about the C=N bond is Z. The two mol­ecules are related to one another by a pseudo inversion centre.