Synthesis and characterization of some novel 2‐{2‐[1‐(3‐substituted‐phenyl)‐1H‐1,2,3‐triazol‐4‐yl‐] ethyl}‐1‐substituted‐1H‐benzo [d] imidazole derivatives

Synthesis of some novel 2‐{2‐[1‐(3‐substitutedphenyl)‐1H‐1,2, 3‐triazol‐4‐yl‐]ethyl)‐1H‐benzo[d]‐imidazole derivatives, by the condensation of o‐phenylenediamine with 3‐(1‐(3‐substituted‐phenyl)‐1H‐1,2,3‐triazol‐4‐yl) propanoic acid and then subsequent reactions with different substituted alkyl halides as electrophiles are mentioned. The synthesized compounds were characterized by ¹H NMR, EI‐MS and IR spectroscopic techniques.     

Trimethyl[3‐methyl‐1‐(o‐tolenesulfonyl)indol‐2‐ylmethyl]ammonium iodide and benzyl[3‐bromo‐1‐(phenylsulfonyl)indol‐2‐ylmethyl]tolylamine

The title compounds, C₂₀H₂₅N₂O₂S⁺·I^?, (I), and C₂₉H₂₅BrN₂O₂S, (II), respectively, both crystallize in space group P. The pyrrole ring subtends an angle with the sulfonyl group of 33.6° in (I) and 21.5° in (II). The phenyl ring of the sulfonyl substituent makes a dihedral angle with the best plane of the indole moiety of 81.6° in (I) and 67.2° in (II). The lengthening or shortening of the C—N bond distances in both compounds is due to the electron‐withdrawing character of the phenyl­sulfonyl group. The S atoms are in distorted tetrahedral configurations. The molecular structures are stabilized by C—H?O and C—H?I interactions in (I), and by C—H?O and C—H?N interactions in (II).     

Syntheses of N‐[3‐(1‐methyl‐1H‐2‐imidazolyl)propyl]benzamides and N‐[3‐(1‐methyl‐1H‐2‐imidazolyl)propyl]benzenesulfonamides

A series of substituted N‐(4‐substituted‐benzoyl)‐N‐[3‐(1‐methyl‐1H‐imidazol‐2‐yl)propyl]amines ( 13 ) and N‐arylsulfonyl‐N‐[3‐(1‐methyl‐1H‐imidazol‐2‐yl)propyl]amines ( 14 ) were prepared from the reaction of 3‐(1‐methyl‐1H‐imidazol‐2‐yl)propan‐1‐amine ( 7 ) with substituted benzoyl chloride or substituted‐benzene sulfonyl chloride respectively. Compound 7 was prepared by two independent methods.     

Methanol[1‐(methoxymethanimidoyl)‐2‐(pyridin‐2‐ylmethyl)guanidine]bis(perchlorato)copper(II)

The title complex, [Cu(ClO₄)₂(C₉H₁₃N₅O)(CH₃OH)], was synthesized from a methanolysis reaction of N‐(methylpyridin‐2‐yl)cyanoguanidine (L³) and copper(II) perchlorate hexahydrate in a 1:1 molar ratio. The Cu^II ion is six‐coordinated by an N₃O₃ donor set which confers a highly distorted and asymmetric octahedral geometry. Three N‐donor atoms from the chelating 1‐(methoxymethanimidoyl)‐2‐(pyridin‐2‐ylmethyl)guanidine (L^3m) ligand and one O atom from the methanol molecule define the equatorial plane, with two perchlorate O atoms in the apical sites, one of which has a long Cu—O bond of 2.9074 (19) Å. The dihedral angle between the five‐ and six‐membered chelate rings is 8.21 (8)°. Two molecules are associated into a dimeric unit by intermolecular N—H...O(perchlorate) hydrogen bonds. Additionally, the weakly coordinated perchlorate anions also link adjacent [Cu(ClO₄)₂(L^3m)(CH₃OH)] dimers by hydrogen‐bonding interactions, resulting in a two‐dimensional layer in the (100) plane. Further C—H...O hydrogen bonds link the two‐dimensional layers along [100] to generate a three‐dimensional network.     

Facile synthesis and antimicrobial properties of 2‐(substituted‐benzylsulfanyl)‐1h‐benzimidazoles

A simple and convenient procedure for the preparation of 2‐benzylthiobenzirnidazoles by the reaction of 2‐mercaptobenzimidazole and benzyl bromides in acetone/potassium carbonate condition has been reported and the compounds were screened for their potential antimicrobial activities.     

Chemoselective reaction of formalin with 2‐(5‐substituted‐2‐hydroxybenzylamino)phenols: Synthesis of 6‐substituted 3‐(2‐hydroxyphenyl)‐3,4‐dihydro‐2H‐benzo[e][1,3]oxazines

Reaction of 2‐(5‐substituted‐2‐hydroxybenzylamino)phenols ( 2 ) with formalin in ethanol under reflux has chemoselectively led to 2‐(6‐substituted‐2H—benzo[e][1,3]oxazin‐3(4H)‐yl)phenols ( 3 ) in good yield involving the ring closure of the hydroxyl group of the C‐aryl ring and not that of the N‐aryl ring.     

N‐Methyl‐N‐(1‐phenyl­sulfonyl­indol‐2‐ylmethyl)­aniline

In the title compound, 2‐[(methylphenylamino)methyl]‐1‐(phenylsulfonyl)indole, C₂₂H₂₀N₂O₂S, the indole system is not strictly planar and the dihedral angle between the fused rings is 2.7 (1)°. The angles around the S atom of the sulfonyl substituent deviate significantly from the ideal value for tetrahedral geometry. The pyramidalization at the indole N atom is very small. Of the two C—H?O interactions, one influences the orientation of indole with respect to the sulfonyl group and the other determines the orientation of the phenyl bound to sulfonyl. The phenyl ring of the sulfonyl substituent makes a dihedral angle of 89.6 (1)° with the best plane of the indole. The molecular packing is stabilized by C—H?π and C—H?O hydrogen bonds.     

Design,Synthesis, Characterization,and Antimicrobial Evaluation of Novel 2‐(3, 5‐di methoxy‐4‐((1‐aryl‐1H‐1, 2, 3‐triazole‐4‐yl) methoxy) phenyl) benzo[d]thiazoles

A series of 12 new 2‐(3, 5‐dimethoxy‐4‐((1‐Aryl‐4H‐1, 2, 3‐triazol‐4‐yl) methoxy) phenyl) benzo[d]thiazoles have been synthesized from the reaction of 4‐hydroxy‐3, 5‐dimethoxybenzaldehyde, o‐amino thiophenol, propargyl bromide, and different substituted aromatic azides using “click chemistry”. The structures of these compounds were established on the basis of Fourier Transform infrared, ¹H NMR, ¹³C–NMR, and mass spectral analysis. Compounds ( 6a–l ) were screened for in vitro antimicrobial activity.     

Synthesis of new 2‐ferrocenyl‐5‐fluoro‐6‐(4‐substituted‐1‐piperazinyl)‐1H‐benzimidazoles of potential biological interest

New substituted 2‐ferrocenylbenzimidazole derivatives are prepared by the oxidation of corresponding Schiff's bases in situ, generated from corresponding 1,2‐diamino‐4‐fluoro‐5‐(1‐piperazinyl)benzenes and 2‐ferrocenecarboxaldehyde using nitrobenzene.     

Synthesis,characterization and polymerization of the novel carbazole‐based monomer 9‐(bicyclo[2.2.1]hept‐5‐en‐2‐ylmethyl)‐9H‐carbazole

Synthesis and characterization of a novel carbazole‐based monomer, 9‐(bicyclo[2.2.1]hept‐5‐en‐2‐ylmethyl)‐9H‐carbazole (BHMCZ) and its copolymerization with ethylene by using two metallocene/MAO catalyst systems are presented. The monomer was characterized by means of NMR spectroscopy, MS and elementary analysis. Copolymerization studies were conducted using [Ph₂C(Ind)(Cp)ZrCl₂] and [Ph₂C(Flu)(Cp)ZrCl₂] catalysts. The [Ph₂C(Ind)(Cp)ZrCl₂] catalyst gave a copolymer containing as much as 4.6 mol‐% of BHMCZ. Polymers were characterized using NMR spectroscopy, gel permeation chromatography (GPC) and differential scanning calorimetry (DSC).     

3‐(2‐(2‐Oxo‐2H‐chromene‐3‐carbonyl)hydrazono)‐N‐(pyridin‐2‐yl)butanamide Complexes: Synthesis,Characterization, DFT,Biological, and Ion‐flotation studies

Schiff base complexes of Cu(II), Ni(II), Cd(II), and Zn(II) with 3‐(2‐(2‐oxo‐2H ‐chromene‐3‐carbonyl)hydrazono)‐N ‐(pyridin‐2‐yl)butanamide (H₂L) were produced. The synthesized compounds were deduced by elemental analysis, molar conductance, magnetic susceptibility, and spectroscopic techniques. The geometry of the prepared complexes was estimated by applying DFT method. Also, Cu(II) and Zn(II) were separated using a simple, quick, and low‐cost quantitative flotation technique preceding to their determinations using atomic absorption spectrophotometric (AAS). Additionally, the biological activities (antimicrobial, antioxidant, and cytotoxic) of isolated compounds were carried out.     

1‐Hydroxy‐1H‐benzo[d][1,2,6]oxazaborinin‐4(3H)‐one

The structure of the title compound, C₇H₆BNO₃, a new boron heterocycle, prepared by the condensation of (2‐ethoxycarbonylphenyl)boronic acid and hydroxylamine, reveals the specific mode of intramolecular condensation between a phenylboronic acid and an ortho hydroxamic acid substituent. The crystal structure shows that dehydration occurs to form a planar oxazaborinine ring possessing both phenol‐like B—O—H and lactam functional groups. In the extended structure, intermolecular hydrogen bonding generates a 14‐membered ring. To our knowledge, this is the first crystal structure determination involving a six‐membered ring that exhibits consecutive B—OH, O, NH, and C=O functional groups.     

Highly Efficient [3 + 2] Cycloaddition: Click Synthesis of Novel 1H‐indol‐3‐yl‐benzo[d]imidazole Bis‐triazoles

A series of novel 1‐((1H‐1,2,3‐triazol‐4‐yl)methyl)‐2‐(1‐((1H‐1,2,3‐triazol‐4‐yl)methyl)‐5‐substituted‐1H‐indol‐3‐yl)‐6‐substituted‐1H‐benzo[d]imidazoles 5a – i have been prepared using click chemistry as an ideal strategy where [3 + 2] cycloaddition of azides with terminal alkynes has been developed as the target compounds. In route‐II, 5‐substituted‐1H‐indole‐3‐carbaldehydes 1a – c react with 5‐substituted orthophenylenediamine 8 to give desired products, that is, 6‐substituted‐2‐(5‐substituted‐1H‐indol‐3‐yl)‐1H‐benzo[d]imidazole 6a – i . Here, 6a – i react with 2 equiv of propargylbromide 7 to give novel 6‐substituted 2‐(5‐substituted‐1‐(prop‐2‐yn‐1‐yl)‐1H‐indol‐3‐yl)‐1‐(prop‐2‐yn‐1‐yl)‐1H‐benzo[d]imidazole 4a – i . 4a – i were reacted with 2 equiv of NaN₃ in t‐butanol/water (1:2) and add catalytic amount of CuSO₄.5H₂O. Stir the reaction mixture at room temperature to get the target products 5a – i . Here, obtained products contain four rings, that is, one indole, two triazoles, and one benzimidazole. The main advantages of this method are short reaction times, easy workup, higher yields (88–92%), and no by‐products formation.     

Heteronuclear NMR spectroscopic investigations of hydrogen bonding in 2‐(benzo[d]thiazole‐2′‐yl)‐N‐alkylanilines

The 2‐(benzo[d]thiazole‐2′‐yl)‐N‐alkylanilines have previously revealed the presence of a strong intramolecular hydrogen bond. This in turn gives rise to a more complicated multiplet for the protons attached to the carbon adjacent to the amino group. This intramolecular hydrogen bond was investigated by a deuterium exchange experiment using heteronuclear NMR spectroscopy (¹H, ¹³C, ¹⁵ N and ²H). We observed changes in the multiplet structure and chemical shifts providing further evidence that the deuterium replaces the hydrogen in the intramolecular hydrogen bond. A time course study of the D₂O exchange confirmed the presence of a strong hydrogen bond. The comparison of the structures obtained by X‐ray crystallography showed a very small difference in planarity between the two‐substituted and four‐substituted amino compounds. In both the cases, the phenyl ring is not absolutely coplanar with the thiazole unit. The existence of this intramolecular hydrogen bond in 2‐(benzo[d]thiazole‐2′‐yl)‐N‐alkylanilines was further confirmed by single crystal X‐ray crystallography. Copyright © 2015 John Wiley & Sons, Ltd.     

A Facile Synthesis of Novel (Z)‐ethyl‐3‐(5‐substituted‐1‐alkyl/aryl‐1H‐indol‐3‐yl)‐2‐(1H‐tetrazol‐5‐yl)acrylate

A novel route was developed for synthesis of high potential 1H‐tetrazoles by using conventional method. Tetrazole scaffold is a promising pharmacophore fragment, frequently used in the development of various novel drugs. Here, the novel (Z)‐3‐(N‐alkyl‐indol‐3‐yl)‐2‐(1H‐tetrazole‐5‐yl)acrylates 5 ( a – i ) have been synthesized from (Z)‐ethyl‐3‐(1H‐indol‐3‐yl)2‐(1H‐tetrazol‐5‐yl)acrylates 4 ( a – c ) by using various alkylating agents such as Dimethyl Sulphate (DMS), Diethyl Sulphate (DES), and benzyl chloride; 4 ( a – c ) were synthesized from sodium azide in the presence of copper sulfate in dimethylformamide; 3 ( a – c ) have been prepared by Knoevenagel condensation of indole‐3‐carbaldehyde 1 ( a – c ) and ethylcyanoacetate 2 in the presence of L‐Proline as a catalyst at room temperature in ethanol for an hour. This is an efficient and clean click chemistry method that has various advantages such as easy workup, higher yields, shorter reaction times, and more economical.