Stereoselective synthesis and X-ray structure determination of novel 1,2-dihydroquinolinehydrazonopropanoate derivatives

A novel series of 1,2-dihydroquinolinhydrazonopropanoate have been synthesized via a convenient aza-Michael addition reaction between hydrazinylquinolinones and ethyl propiolate in ethanol under refluxing temperature. The structures for all obtained products were confirmed with FTIR, NMR spectrums, as well as mass spectrometry. In addition, the monoclinic structure for compounds 8a, 8c, and 8d was also confirmed via X-ray crystallography analyses. The E-configuration for the obtained products was confirmed form the X-ray analysis. On the other hand, the crystal packing shows that the intermolecular and hydrogen bonds between atoms are parallel to the bc plan

Chemistry of Substituted Thiazinanes and Their Derivatives

Thiazinanes and its isomeric forms represent one of the most important heterocyclic compounds, and their derivatives represented a highly potent drug in disease treatment such as, 1,1-dioxido-1,2-thiazinan-1,6-naphthyridine, which has been shown to have anti-HIV activity by a mechanism that should work as anti-AIDS treatment, while (Z)-methyl 3-(naphthalen-1-ylimino)- 2-thia-4-azaspiro[5 5]undecane-4-carbodithioate showed analgesic activity, cephradine was used as antibiotic and chlormezanone was utilized as anticoagulants. All publications were interested in the chemistry of thiazine (partially or fully unsaturated heterocyclic six-membered ring containing nitrogen and sulfur), but no one was dealing with thiazinane itself which encouraged us to shed new light on these interesting heterocycles. This review was focused on the synthetic approaches of thiazinane derivatives and their chemical reactivity

Synthesis and structure confirmation of 2,4-disubstituted thiazole and 2,3,4-trisubstituted thiazole as thiazolium bromide salts

The synthesis of 4-substituted 2-(2-arylhydrazinyl)thiazol-3-ium bromides and 4-aryl-2-(substituted amino)-3-(phenylamino)thiazol-3-ium bromide derivatives in high yields from the interaction of mono- and di-substituted thiosemicarbazides with phenacyl bromide derivatives is reported. The synthesized products have been elucidated using various spectroscopic tools such as IR, NMR, and mass spectrometry. Also the structure of three of the obtained compounds have been confirmed using X-ray crystallographic analyses, which showed that compounds 2-[2-(2,4-dinitrophenyl)hydrazinyl]-4-phenylthiazol-3-ium bromide and 4-phenyl-2,3-bis(phenylamino)thiazol-3-ium bromide crystals have a monoclinic shape and belonged to space groupP2(1)/c, whereas the crystals of 4-phenyl-2-(2-tosylhydrazinyl)thiazol-3-ium bromide show an orthorhombic shape with the space groupPbca [GRAPHICS] .Peer reviewe

Synthesis, Antioxidant and Antiproliferative Actions of 4-(1,2,3-Triazol-1-yl)quinolin-2(1H)-ones as Multi-Target Inhibitors

The reaction of 4-azido-quinolin-2(1H)-ones 1a–e with the active methylene compounds pentane-2,4-dione (2a), 1,3-diphenylpropane-1,3-dione (2b), and K$_2$CO$_3$ was investigated in this study. This approach afforded 4-(1,2,3-triazol-1-yl)quinolin-2(1H)-ones 3a–j in high yields and purity. All newly synthesized products’ structures were identified. Compounds 3a–j were tested for antiproliferative activity against a panel of four cancer cell lines. In comparison to the reference erlotinib (GI$_{50}$ = 33), compounds 3f–j were the most potent derivatives, with GI$_{50}$ values ranging from 22 nM to 31 nM. The most effective antiproliferative derivatives, 3f–j, were subsequently investigated as possible multi-target inhibitors of EGFR, BRAF$^{V600E}$, and EGFR$^{T790M}$. Compound 3h was the most potent inhibitor of the studied molecular targets, with IC50 values of 57 nM, 68 nM, and 9.70 nM, respectively. The apoptotic assay results demonstrated that compounds 3g and 3h function as caspase-3, 8, and Bax activators as well as down-regulators of the antiapoptotic Bcl2, and hence can be classified as apoptotic inducers. Finally, compounds 3g and 3h displayed promising antioxidant activity at 10 µM, with DPPH radical scavenging of 70.6% and 73.5%, respectively, compared to Trolox (77.6%)

Synthesis and crystallographic evaluation of diazenyl- and hydrazothiazoles. [5.5] sigmatropic rearrangement and formation of thiazolium bromide dihydrate derivatives

In this investigation the synthesis of diazenylthiazoles (3a-e) by the reaction of arylthiosemicarbazides with omega-bromoacetophenones via Eschenmoser-coupling reaction in acetonitrile and equimolar amounts of triethylamine and triphenylphosphine. Upon heating 1,4-disubstituted thiosemicarbazides with omega-bromoacetophenones in absolute ethanol, hydrazothiazoles (16a-i) were precipitated. On the other hand, the reaction of arylthiosemicarbazides with omega-bromoacetophenones in refluxing ethanol yielded 2-amino-5-[4-aminophenyl]-4-phenylthiazolium bromide dihydrate derivatives (19a-g) via [5.5] sigmatropic shift. The studied products were further characterized by IR, H-1 NMR, C-13 NMR and mass spectrometry. X-ray single crystal of 3a and 16h showed that, the molecules crystallized in the triclinic crystal system, space group P2(1)/c. Whereas the X-ray single crystal of 19b showed the molecule crystalized in orthorhombic, space group P2(1)2(1)2(1). In the crystal of 19b, the lattice water and bromide ion associated through hydrogen bonded with thiazole-NH2. (C) 2018 Published by Elsevier B.V.Peer reviewe

Eschenmoser-Coupling Reaction Furnishes Diazenyl-1,2,4-triazole-5(4H)-thione Derivatives

Diazenyl 1,2,4-triazol-5(4H)-thione derivatives were synthesized in good yields via Eschenmoser-coupling reaction and nucleophilic attack between 1,4-disubstituted thiosemicarbazides and 2,3,5,6-tetrachloro-1,4-benzoquinone (p-CHL). The structure of the synthesized compounds was confirmed by IR, NMR and mass spectral data as well as single crystal X-ray analysis.Peer reviewe

Regioselective and stereoselective synthesis of epithiomethanoiminoindeno[1,2-b]furan-3-carbonitrile : heterocyclic [3.3.3]propellanes

Synthesis of heteropropellanes in one step: the reaction between dicyanomethylene-1,3-indanedione (CNIND) and N-substituted-2-(2,4-dinitrophenyl)hydrazinecarbothioamides, furnished (3aR,8bS,Z)-2-amino-9-substituted-10-(2-(2,4-dinitrophenyl)hydrazono)-4-oxo-4H-3a,8b-(epithiomethanoimino)indeno[1,2-b]furan-3-carbonitrile as a type of (2,4-dinitrophenyl)hydrazono[3.3.3]propellanes in good yields as single diastereomers. Structure determination and confirmation of the synthesized products have been achieved using various and modern spectroscopic techniques such as IR, NMR (H-1 NMR and(13)C NMR), mass spectrometry, as well as X-ray crystal analysis. The X-ray structure data cleared that the molecule of7awas crystalized as monoclinic, space group C2/c (no.15). [GRAPHICS] .Peer reviewe

Reactivity of 2-substituted hydrazinecarbothioamides towards tetracyanoethylene and convenient synthesis of (5-amino-2-diazenylthiazolylmethylene) malononitrile derivatives

2-{Amino-[5-amino-2-(substituted diazenyl) thiazol-4-yl] methylene} malononitriles were synthesized from the reaction of 2-substituted hydrazinecarbothioamides with tetracyanoethylene (TCNE) to give tetracyanoethane adduct, followed by heterocyclization afforded the target compounds. The structure of (E)-2-{amino-[5-amino-2-(phenyldiazenyl) thiazol-4-yl] methylene} malononitrile was supported by single crystal X-ray crystallography.Peer reviewe

A convenient and efficient synthesis of thiazolidin-4-ones via cyclization of substituted hydrazinecarbothioamides

2-Substituted hydrazinecarbothioamides and N ,2-disubstituted hydrazinecarbothioamides react in high yield with dimethyl acetylenedicarboxylate (DMAD) to give 4-oxo-Z-(thiazolidin-5-ylidene) acetate derivatives. Several mechanistic options involving interaction are presented. The structures of thiazolidin-4-ones have been unambiguously confirmed by single crystal X-ray crystallography. (C) 2014 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.Peer reviewe

Convenient diastereoselective synthesis of annulated 3-substituted-(5S*,6S*,Z)-2-(2-(2,4-dinitrophenyl)hydrazono)-5,6-diphenyl-1,3-thiazinan-4-ones

Racemic 2-(2,4-dinitrophenyl)hydrazono)-5,6-diphenyl-1,3-thiazinan-4-ones and (Z)-N '-(2,4-dinitrophenyl)-2,3-diphenylacrylohydrazide were formed during the diastereoselective reaction between 4-substituted 1-(2,4-dinitrophenyl)thiosemicarbazides and 2,3-diphenylcycloprop-2-enone under refluxing ethanol. The structures of the synthesized compounds were confirmed by single-crystal X-ray analyses. [GRAPHICS] .Peer reviewe