Talaat I. El-Emary

Assiut University · Department of Chemistry

Background This paper showed the synthetic capability of the indolo[2,3-b]quinoxaline nucleus to be provided as an excellent precursor for the synthesis of various heterocyclic compounds. These synthetic routes proceed via the formation of 3-(6H-indolo[2,3-b]quinoxalin-6-yl)propane hydrazide (2). The carbohydrazide 2 and its reactions with differen...

In the title compound, C 33 H 26 N 4 O 4 , the two fused five-membered rings and their N-bound aromatic substituents form a pincer-like motif. The relative conformations about the three chiral carbon atoms are established. In the crystal, a combination of C—H...O and C—H...N hydrogen bonds and C—H...π(ring) interactions leads to the formation of la...

A pyrazolyl nitrone (2) underwent 1,3-dipolar cycloadditions to afford some N-substituted maleimides (3a–o). An atropisomeric character was introduced into the formed cycloadducts by using maleimides that have a restricted rotation around the C–N bond. Also, facial selectivity of both endo and exo cycloaddition was observed where the major atropiso...

5-Carbohydrazides and 5-carbonylazides of pyrazolo[3,4- b]pyridines are used to synthesize new heterocyclic derivatives. Some unexpected behaviors are observed in the reactions of the above two species. The structures of the obtained compounds are proved by spectroscopic studies together with elemental and X-ray structure analyses.

Two individual examples of pyrazolo[3,4‐b]pyridine‐5‐carbonyl azides and hydrazides were reacted with various nucleophilic reagents. Different unexpected behaviors was observed. NMR, IR, mass spectra together with elemental analyses and X‐ray structure analyses, were used to prove the structure of the obtained products.

An efficient protocol for the construction of tetracyclic fused quinolines (pyrazole-fused azepino-, azocino-, and azonino[3,2-b]quinolinones) via consecutive Friedel–Crafts and Beckmann reactions has been developed. The key steps in the syntheses of these new molecular scaffolds involve acid-mediated cyclization of 2-(pyrazol-3-yl)quinoline based...

An efficient protocol for the construction of tetracyclic fused quinolines (pyrazole-fused azepino-, azocino-, and azonino[3,2-b]quinolinones) via consecutive Friedel–Crafts and Beckmann reactions has been developed. The key steps in the syntheses of these new molecular scaffolds involve acid-mediated cyclization of 2-(pyrazol-3-yl)quinoline based...

p>Aim and Objective: This work presents the synthetic capability and the exploitation of 1,3-diphenyl- 1H-pyrazole-4-carboxladehyde 1 and 5-diphenyl pyrazolyl-2-pyrazoline analogue 8 to serve as excellent precursors for the synthesis of substituted indol-2,3-dione, trizolo[3,4-a]benzazoles, thiazolo[2,3- a]benzimidazole-3-one, substituted 2-pyrazol...

New derivatives of pyrazolo[3,4-b]pyrazines and related heterocycles were synthesized using 5-amino-3-methyl-4-nitroso-1-phenyl-pyrazole (1) as a starting material. The 5-acetyl derivative 15 was shown to be a useful key intermediate for the synthesis of several derivatives of pyrazolopyrazines. Some of the prepared compounds were evaluated for the...

Basic hydrolysis of the starting 1,6-diphenyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile 1, afforded the corresponding carboxylic acid 2, which was in turn converted to its methyl ester 3 and subsequently reacted with hydrazine hydrate to afford the corresponding 5-carbohydrazide 4. Compound 4 was used as a key intermediate for the synthesi...

The title compound, C 16 H 13 N 3 OS, comprises an oxadiazolethione ring bound to the N atom of an almost planar carbazole ring system (r.m.s. deviation = 0.0088 Å) through an ethylene chain. The oxadiazole ring is inclined to the the carbazole ring system by 40.71 (6)°. In the crystal, N—H...O, N—H...S, C—H...N and C—H...S hydrogen bonds combine w...

The title compound, C16H13N3OS, comprises an oxa­diazo­lethione ring bound to the N atom of an almost planar carbazole ring system (r.m.s. deviation = 0.0088 Å) through an ethyl­ene chain. The oxa­diazole ring is inclined to the the carbazole ring system by 40.71 (6)°. In the crystal, N—H⋯O, N—H⋯S, C—H⋯N and C—H⋯S hydrogen bonds combine with C—H⋯π(...

Carbazole-containing natural product scaffolds have frequently been isolated from diverse marine invertebrates including strychnos alkaloids such as strychninolones B and their derivatives e.g. Brucinolones, Picrasidin Q and Olivacin and vomicin. 1 Carbazole alkaloids show different type of biological activities such as cytotoxic, antitumor, antivi...

With an intention to synergize the antimicrobial activity of 1,3-diphenyl pyrazole and chromene derivatives, 20 hybrid compounds were synthesized and evaluated for their antimicrobial activity. Structures of the newly synthesized compounds were established by elemental analysis and spectral data. All compounds were evaluated for their antimicrobial...

In the title compound, C 13 H 12 N 6 O, the pyrazolo[3,4- b ]pyrazine ring system is planar (r.m.s. deviation for the nine fitted atoms = 0.024 Å) and makes a dihedral angle of 5.72 (6)° with the pendent phenyl ring. The molecular conformation is stabilized by intramolecular N—H...O and C—H...N hydrogen bonds, each generating an S (6) loop. In the...

The title compound, C 15 H 13 NO 2 , crystallizes with two molecules ( A and B ) in the asymmetric unit. The carbazole ring systems of both molecules are close to planar (r.m.s deviations = 0.035 and 0.053 Å). In the crystal, A + A and B + B inversion dimers linked by pairs of O—H...O hydrogen bonds generate R2² (8) loops and weak C—H...π interacti...

In the title compound, C 22 H 18 N 4 S·C 2 H 6 OS, the central triazolethione ring is inclined to the carbazole ring system by 13.97 (18)° and to the phenyl ring by 66.4 (1)°. The lattice solvent, dimethyl sulfoxide, is strongly hydrogen bonded to the triazolethione ring. In the crystal, the main molecules form columns parallel to the a axis, with...

In the crystal of the title compound, C 16 H 15 N 5 S·C 2 H 6 OS, both the 1,2,4-triazole derivative molecules and the disordered [refined occupancy ratio = 0.604 (1):0.396 (1)] dimethyl sulfoxide solvent molecules form centrosymmetric dimers, by way of pairwise N—H...S and C—H...O hydrogen bonds, respectively. In the crystal, the two types of dime...

6-chloro-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile (1) was utilized as key intermediate for the synthesis of new 6-amino derivatives (2-17) by heating with a number of aliphatic amines. Heating 1 with aromatic amines under similar conditions failed to give the corresponding amino derivatives. The new compounds were fully character...

Abstract A green and efficient method for the synthesis of novel 5-(N-substituted indol-2-yl)-8- hydroxyquinolines has been achieved in good to excellent yields by one-pot three-component Domino reaction of 5-chloroacetyl-8-hydroxyquinoline with amines and dimedone using DABCO as a basic catalyst in ethanol under reflux conditions. The products wer...

A novel series of 6-substituted pyrazolo[3,4-g]pteridines 2–9 and pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pteridin-2(3H)-one (thione) 10 and 11 was synthesized using the starting compound 3,7-dimethyl-1-phenylpyrazolo[4′,3′:5,6]pyrazino[2,3-d][1,3]oxazin-5(1H)-one 2. The structure of the newly synthesized compounds was elucidated by IR, 1H-NMR, 13C-NM...

كتاب الكيمياء العامة لطلاب السنوات الأولى بكليات العلوم والتربية

MATTER AND ENERGY, Chemical and physical properties, Chemical and physical changes, MEASURMENTS IN CHEMISTRY, CONVERSION FACTORS RELATING LENGTH, VOLUME AND MASS UNITS, Conversion from decimal to exponential, Heat and temperature, Significant figures and calculations, SUBSTANCES, MIXTURES, ELEMENTS, AND COMPOUNDS, The periodic table of the elements...

الكيمياء العضوية لطلاب السنوات الأولى بكليات التربية

Lecutre for Prepharmacy students, Faculty of Pharmacy, Assiut University

In the title compound, C 22 H 18 ClN 3 O, the carbazole ring system is essentially planar (r.m.s deviation = 0.003 Å), and makes a dihedral angle of 9.01 (8)° with the plane of the chlorophenyl ring. In the crystal, neighbouring molecules are linked into centrosymmetric R 2 2 (8) dimers by pairs of N—H...O interactions and into a three-dimensional...

New derivatives of a pyrazole-based fused triheterocyclic system, namely pyrazolo[4,3-g]pteridine, have been synthesized. Starting from the pyrazolopyrazine amino nitrile (8), the pyrazolopyrazino[1,3]oxazinone 10 was obtained. The latter compound was the key intermediate for the synthesis of several new pyrazolo[4,3-g]pteridines and related hetero...

methyl-14-phenyl-10,13,14,16-tetraazatetra-cyclo[7.7.0.0 2,7 .0 11,15 ]hexadeca-1(16),2,4,6,9,11(15),12-heptaen-8-yl-idene]hydroxylamine 1,4-dioxane hemisolvate In the title solvate, C 19 H 13 N 5 OÁ0.5C 4 H 8 O 2 , the main molecule is almost planar (r.m.s. deviation for the non-H atoms = 0.066 Å). The hydroxylamine group is disordered over two or...

A series of newly Atophans (Cinchophen, 2-phenylcin choninic acid) heterocycles have been synthesized by employing 2-phenylquinoline-4-carboxylic acid (cinc hophen) as starting material with the aim of evalua ting their antimicrobial activity. The key intermediate 2-phenylquinoline-4-carbohydrazide (3) was smoothly synthesized by reaction of phe...

In the title compound, C 15 H 15 N 7 , the phenyl ring is inclined by 19.86 (5)° to the mean plane of the pyrazolo[3,4- b ]pyrazine core. In the crystal, N—H...N and C—H...N hydrogen bonds form [010] chains, which stack via π–π interactions [centroid–centroid distance between the pyrazole rings = 3.4322 (7) Å].

The title compound, C16H16N4 O2 , crystallizes with two molecules in the asymmetric unit, one of which shows disorder of the acetate group over two sets of sites in a 0.799 (2):0.201 (2) ratio. The phenyl group has a similar but opposite sense of twist relative to the pyrazole ring in the two molecules, as indicated by the syn N—N—Car—Car (ar = aro...

The title compound, C 15 H 14 N 4 O, crystallizes with two molecules in the asymmetric unit with similar conformations (r.m.s. overlay fit for the 20 non-H atoms = 0.175 Å). In the first molecule, the dihedral angles between the planes of the central pyrazole ring and the pendant phenyl and pyrrole rings are 42.69 (8) and 51.88 (6)°, respectively,...

The present work describes the synthesis of a novel series of heterocyclic moieties derived from 5-acetylpyrazolo[3,4-b]pyridine (1). The formation of chalcones (2a-d) was utilized to synthesize pyrazoline, isoxazoline and pyrimidine derivatives (3-10). Thiosemicarbazone and semicarbazone (11, 17) were utilized to synthesize other new triazolethion...

In the title compound (Fig. 1), the central pyrazole ring makes dihedral angles of 58.99 (5) and 34.95 (5)°, respectively, with the the pyrrolyl and phenyl rings. Weak, pairwise C12—H12···O1 interactions across centers of symmetry form dimers which are further associated into corrugated sheets running approximately parallel to (100) via weak C15—...

sj5428 Acta Cryst. (2014). E70 Mague et al. C 15 H 13 N 3 O ISSN 1600-5368 ARTICLE IN PRESS – Acta Cryst. E Crystal structure of 3-methyl-1-phenyl-5-(1H-pyrrol-1-yl)-1H-pyrazole-4-carbaldehyde How to cite your article in press Your article has not yet been assigned page numbers, but may be cited using the doi: You will be sent the full citation whe...

1,4-Disubstituted thiosemicarbazides reacted with dimethyl acetylenedicarboxylate with formation of (2-hydrazono-4-oxothiazolidin-5-ylidene)acetates and, in one case, a (2-imino-1,3,4-thiadiazin-5-on-6- ylidene)acetate. Several mechanistic options involving nucleophilic interaction are presented. The structures of all newly synthesized compounds we...

h i g h l i g h t s " FT-IR and FT-Raman spectra of the title compound were recorded and analyzed. " 13 C and 1 H NMR spectra are used to elucidate the structure. " Experimental spectra compared with theoretically simulated spectra of 5-APHC. " HOMO and LUMO analysis and several thermodynamic properties have been performed. a b s t r a c t FT Raman...

Presentation to Assiut University

10.1002/jhet.1118 Published online 00 Month in Wiley Online Library (wileyonlinelibrary.com). The review summarizes recent literatures dealing with the synthetic tools of thieno[2,3-d]pyrimidine derivatives including their biological activities and their applications in the synthesis of heterocycles. J Heterocyclic Chem., 00, 00 (2013).

FT Raman and IR spectra of the crystallized biologically active molecule, 5-Amino-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde (5-APHC, C11H11N3O) have been recorded and analyzed. The equilibrium geometry, bonding features and harmonic vibrational frequencies of 5-APHC have been investigated with the help of B3LYP density functional theory (DFT) me...