2‐[2‐(Pyrrolidin‐2‐yl)propan‐2‐yl]‐1H‐pyrrole and its amide derivative 1‐{2‐[2‐(1H‐pyrrol‐2‐yl)propan‐2‐yl]pyrrolidin‐1‐yl}ethanone

In the title compounds, C₁₁H₁₈N₂, (II), and C₁₃H₂₀N₂O, (III), the pyrrolidine rings have twist conformations. Compound (II) crystallizes with two independent molecules (A and B) in the asymmetric unit. The mean planes of the pyrrole and pyrrolidine rings are inclined to one another by 89.99 (11) and 89.35 (10)° in molecules A and B, respectively. In (III), the amide derivative of (II), the same dihedral angle is much smaller, at only 13.42 (10)°. In the crystal structure of (II), the individual molecules are linked via N—H...N hydrogen bonds to form inversion dimers, each with an R²₂(12) graph‐set motif. In the crystal structure of (III), the molecules are linked via N—H...O hydrogen bonds to form inversion dimers with an R²₂(16) graph‐set motif.     

A Novel and Efficient Synthesis of 3‐[(4,5‐Dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐chromen‐2‐ones (=3‐[(4,5‐Dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐1‐benzopyran‐2‐ones)

An efficient one‐pot synthesis of 3‐[(4,5‐dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐chromen‐2‐one (=3‐[(4,5‐dihydro‐1H‐pyrrol‐3yl)carbonyl]‐2H‐1‐benzopyran‐2‐one) derivatives 4 by a four‐component reaction of a salicylaldehyde 1 , 4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one, a benzylamine 2 , and a diaroylacetylene (=1,4‐diarylbut‐2‐yne‐1,4‐dione) 3 in EtOH is reported. This new protocol has the advantages of high yields (Table), and convenient operation. The structures of these coumarin (=2H‐1‐benzopyran‐2‐one) derivatives, which are important compounds in organic chemistry, were confirmed spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme 2).     

Synthesis of Novel 1‐(Benzo[d]thiazol‐2‐yl)‐1H‐pyrrol‐2(5H)‐ones

The titled products comprising of two mutually merged bioactive nucleuses, 2‐aminobenzo[d]thiazole and 2,5‐dihydropyrrole rings, were obtained from the reaction between dialkyl acetylenedicarboxylates and alkyl 2‐(benzo[d]thiazol‐2‐yl)amino‐2‐oxoacetates in the presence of triphenylphosphine at RT.     

Two hydrates of 2,6‐bis­(1H‐benzimidazol‐2‐yl)­pyridine

The structures of the mono‐ and sesquihydrates of 2,6‐bis(1H‐benz­imi­da­zol‐2‐yl)­pyridine (bbip) are reported. Phase (I), C₁₉H₁₃N₅·H₂O, has one water and one bbip mol­ecule in the asymmetric unit, while phase (II), C₁₉H₁₃N₅·1.5H₂O, has three water mol­ecules and two bbip mol­ecules in the asymmetric unit. The compounds exhibit very similar molecular geom­etries but different packing organizations, which result from intricate hydrogen‐bonding schemes.     

Tris(1H‐benzimidazol‐2‐yl­meth­yl)­amine–solvent adducts

The tris­(1H‐benzimidazol‐2‐yl­meth­yl)­amine (ntb) mol­ecule crystallizes in different solvent systems, resulting in two kinds of adduct, namely the monohydrate, C₂₄H₂₁N₇·H₂O or ntb·H₂O, (I), and the acetonitrile–methanol–water (1/0.5/1.5) solvate, C₂₄H₂₁N₇·C₂H₃N·0.5CH₄O·1.5H₂O or ntb·1.5H₂O·0.5MeOH·MeCN, (II). In both cases, ntb adopts a tripodal mode to form hydrogen bonds with a solvent water mol­ecule via two N—H⋯O and one O—H⋯N hydrogen bond. In (I), the ntb·H₂O adduct is further assembled into a two‐dimensional network by N—H⋯N and O—H⋯N hydrogen bonds, while in (II), a double‐stranded one‐dimensional chain structure is assembled via N—H⋯O and O—H⋯O hydrogen bonds, with the acetonitrile mol­ecules located inside the cavities of the chain structure.     

(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.     

Isomeric 3‐ and 4‐chloro‐N‐[1‐(1H‐pyrrol‐2‐yl)ethylidene]aniline

The title isomers, namely 3‐chloro‐N‐[1‐(1H‐pyrrol‐2‐yl)ethylidene]aniline, (I), and 4‐chloro‐N‐[1‐(1H‐pyrrol‐2‐yl)ethylidene]aniline, (II), both C₁₂H₁₁ClN₂, differ in the position of the chlorine substitution. Both compounds have the basic iminopyrrole structure, which shows a planar backbone with similar features. The dihedral angle formed by the planes of the pyrrole and benzene rings is 75.65 (7)° for (I) and 86.56 (8)° for (II). The H atom bound to the pyrrole N atom is positionally disordered and partial protonation occurs at the imino N atom in (I), while this phenomenon is absent from the structure of (II). Packing interactions for both compounds include intermolecular N—H...N hydrogen bonds and C—H...π interactions, forming centrosymmetric dimers for both (I) and (II).     

Tris­[2‐(2‐oxazolin‐2‐yl)­phenolato]­iron(III)

The title compound, tris­[2‐(4,5‐dihydrooxazol‐2‐yl‐κN)phenolato‐κO]­iron(III), [Fe(C₉H₈NO₂)₃], is disordered over a non‐crystallographic twofold rotation axis perpendicular to the crystallographic threefold rotation axis. The disorder can be a pure rotational disorder of an iron complex in the facial configuration, or the consequence of a mixture of facial and meridional configurations. In the latter case, at least 25% of the iron complexes must adopt the facial configuration in order to obtain the disorder ratio observed in the crystal.     

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.     

[2‐(1H‐Inden‐3‐yl)­ethyl]­di­phenyl­phos­phine–borane

The title compound, C₂₃H₂₄BP, crystallizes in the centrosymmetric space group P2₁/c, with one mol­ecule in the asymmetric unit. The indene moiety is essentially planar. The P—B bond length is 1.923 (3) Å, which is within the expected range.     

(Z)‐3‐(1H‐Indol‐3‐yl)‐2‐(3‐thienyl)­acrylo­nitrile and (Z)‐3‐[1‐(4‐tert‐butyl­benzyl)‐1H‐indol‐3‐yl]‐2‐(3‐thienyl)­acrylo­nitrile

(Z)‐3‐(1H‐Indol‐3‐yl)‐2‐(3‐thienyl)­acrylo­nitrile, C₁₅H₁₀N₂S, (I), and (Z)‐3‐[1‐(4‐tert‐butyl­benzyl)‐1H‐indol‐3‐yl]‐2‐(3‐thienyl)­acrylo­nitrile, C₂₆H₂₄N₂S, (II), were prepared by base‐catalyzed reactions of the corresponding indole‐3‐carbox­aldehyde with thio­phene‐3‐aceto­nitrile. ¹H/¹³C NMR spectral data and X‐ray crystal structures of compounds (I) and (II) are presented. The olefinic bond connecting the indole and thio­phene moieties has Z geometry in both cases, and the mol­ecules crystallize in space groups P2₁/c and C2/c for (I) and (II), respectively. Slight thienyl ring‐flip disorder (ca 5.6%) was observed and modeled for (I).     

1‐(2‐Pyridyl)ethan‐1‐one 8‐quinolylhydrazone and 1‐(1H‐pyrrol‐2‐yl)ethan‐1‐one 8‐quinolylhydrazone

The structures of the title compounds, C₁₆H₁₄N₄, (I), and C₁₅H₁₄N₄, (II), respectively, have been determined, and their molecular packing arrangements compared. Both are essentially flat mol­ecules, with respective dihedral angles between the quinoline and heterocyclic rings of 19.0 (1) and 8.5 (2)°. The pyridyl derivative, (I), packs in a P2₁/c unit cell, while in the pyrrolyl compound, (II), the mol­ecules pack in Pca2₁ and form a crinkled ribbon arrangement through the association of pyrrole NH groups with the quinoline N atoms.     

2(S)‐Amino‐3‐[1H‐imidazol‐4(5)‐yl]­propyl cyclo­hexylmethyl ether di­hydro­chloride and 2(S)‐amino‐3‐[1H‐imidazol‐4(5)‐yl]­propyl 4‐bromo­benzyl ether di­hydro­chloride

(Cyclo­hexyl­methyl­oxy­methyl)(1H‐imidazol‐4‐io­methyl)‐(S)‐ammonium dichloride, C₁₃H₂₅N₃O⁺·2Cl^?, and (4‐bromo­benzyl)(1H‐imidazol‐4‐io­methyl)‐(S)‐ammonium dichloride, C₁₃H₁₈BrN₃O⁺·2Cl^?, are model compounds with different biological activities for evaluation of the hist­amine H3‐receptor activation mechanism. Both title compounds occur in almost similar extended conformations.     

All Solid State Chromium(III) Selective Potentiometric Sensor Based on 2‐(1‐(2‐((3‐(2‐Hydroxyphenyl)‐1H‐pyrozol‐1‐yl)methyl)benzyl)‐1H‐pyrazol‐3‐yl)phenol

Highly selective all solid state electrochemical sensor based on a synthesized compound i.e. 2‐(1‐(2‐((3‐(2‐hydroxyphenyl)‐1H‐pyrozol‐1‐yl)methyl)benzyl)‐1H‐pyrazol‐3‐yl)phenol (I) as an ionophore has been prepared and investigated for the selective quantification of chromium(III) ions. The effect of various plasticizers, viz. dibutyl phosphonate (DBP), dibutyl(butyl) phosphonate (DBBP), nitrophenyl octyl ether (NPOE), tris‐(2‐ethylhexyl)phosphonate (TEP), tri‐butyl phosphonate (TBP), dioctyl phthalate (DOP), dioctyl sebacate (DOS), benzyl acetate (BA) and acetophenone (AP) along with anion excluders NaTPB (sodium tetraphenyl borate) and KClTPB (potassium(tetrakis‐4‐chlorophenyl)borate was also studied. The optimum composition of the best performing membrane contained (I):KClTPB:NPOE:PVC in the ratio 15 : 3 : 40 : 42 w/w. The sensor exhibited near Nernstian slope of 20.1±0.2 mV/decade of activity in the working concentration range of 1.2×10^?7–1.0×10^?1 M, and in a pH range of 3.8–4.5. The sensor exhibited a fast response time of 10 s and could be used for about 5 months without any considerable divergence in potentials. The proposed sensor showed very good selectivity over most of the common cations including Na⁺, Li⁺, K⁺, Cu²⁺, Sr²⁺, Ni²⁺, Co²⁺, Ba²⁺, Hg²⁺, Pb²⁺, Zn²⁺, Cs⁺, Mg²⁺, Cd²⁺, Al³⁺, Fe³⁺and La³⁺. The activity of Cr(III) ions was successfully determined in the industrial waste samples by using this sensor.     

Di­methyl 2‐{[2‐(methoxy­carbonyl)‐1‐(methoxy­carbonyl­methyl)pyrrol‐4‐yl]­methyl­ene}propane­dioate

The title compound, C₁₅H₁₇NO₈, is a pyrrole–ethene derivative with potential biological activity. Although a large part of the mol­ecule is planar, there is no structural evidence for any conjugation push–pull effect across the ethyl­enic bond, which is usually observed for substituted ethyl­enes; π‐electron delocalization appears to be restricted to the 2‐(methoxy­carbonyl)­pyrrole moiety.     

Synthesis of (3,5‐Aryl/methyl‐1H‐Pyrazol‐1‐yl)‐(5‐Arylamino‐2H‐1,2,3‐Triazol‐4‐yl)Methanone

Some new (3,5‐aryl/methyl‐1H‐pyrazol‐1‐yl)‐(5‐arylamino‐2H‐1,2,3‐triazol‐4‐yl)methanones were synthesized and characterized by ¹HNMR, ¹³C NMR, MS, IR spectra data and elemental analyses or high resolution mass spectra (HRMS). During the procedure, Dimroth rearrangement was used in this synthesis.     

1‐Bromo‐2,6‐bis­[(pyrazol‐1‐yl)­methyl]­benzene

The title compound, C₁₄H₁₃BrN₄, has a planar central unit, (C)₂C₆H₃Br, the pendant pyrazole rings forming dihedral angles of 83.8 (3) and 89.3 (3)° with this plane. The pyrazole rings are oriented such that there is an approximate twofold axis coincident with the C—Br bond.     

1H‐Imidazol‐1‐yl 1,2,3,4‐tetra­hydro­isoquinolin‐2‐yl ketone

In the crystal structure of the title compound, C₁₃H₁₃N₃O, the C—N_imidazole bond length of 1.431 (3) Å is shorter than that observed [1.466 (6) Å] in the corresponding carbamoyl­imidazolium salt 3‐methyl‐1‐(1,2,3,4‐tetra­hydro­isoquinolin‐2‐yl­carbonyl)­imidazolium iodide. A comparision of these compounds is used to highlight the structural differences that occur as a result of the imidazolium effect. Weak C—H⋯O hydrogen bonds link mol­ecules into extended tapes in the a direction.     

Bis[bis­(3‐phenyl­pyrazol‐1‐yl)­(pyrazol‐1‐yl)­methane]­copper(II) bis­(per­chlor­ate) acetonitrile disolvate

The title copper(II) complex, [Cu(C₂₂H₁₈N₆)₂](ClO₄)₂·2C₂H₃N, comprises two neutral substituted tris­(pyrazol‐1‐yl)­methane ligands bonded to a central Cu^II ion, which is positioned on a crystallographic inversion center. Six Cu—N bonds are arranged in a distorted octa­hedral fashion. The unsubstituted pyrazole rings on each ligand are oriented trans with respect to each other, inter­digitated with the two 3‐phenyl­pyrazole rings of the other ligand.