Phenyl Isothiocyanate Research Articles

A novel synthesis, X-ray analysis and computational studies of (Z)-ethyl 2-((Z)-5-((dimethylamino)methylene)- 4-oxo-3-phenylthiazolidin-2-ylidene)acetate as a potential anticancer agent

Background4-Thiazolidinone ring is reported to have almost all types of biological activities. Also, it present in many marketed drugs.ResultsEthyl acetoacetate reacted with phenyl isothiocyanate and ethyl chloroacetate in presence of K2CO3 and DMF to afford the thiazolidinone derivative 5. Thiazolidinone 5 reacted with dimethylformamide-dimethylacetal to afford (Z)-ethyl 2-((Z)-5-((dimethylamino) methylene)-4-oxo-3-phenylthiazolidin-2-ylidene)acetate (6). The structure of thiazolidinone 6 was elucidated from its spectral analysis and X-ray crystallography and was optimized using B3LYP/6-31G(d,p) method. The geometric parameters and NMR spectra were discussed both experimentally and theoretically. Also, the natural charges at the different atomic sites were predicted. The synthesized compounds had moderate cytotoxic activity.ConclusionsAn unexpected synthesis of (Z)-ethyl 2-((Z)-5-((dimethylamino)methylene)-4-oxo-3-phenylthiazolidin-2-ylidene)acetate via deacetylation mechanism. The structure was established using X-ray and spectral analysis. The geometric parameters, and NMR spectra were discussed. The synthesized compounds showed moderate anticancer activity.

Novel Bis(2‐cyanoketene‐S,S‐/S,N‐acetals): Versatile Precursors for Novel Bis(aminopyrazole) Derivatives

A synthesis of novel bis(aminopyrazoles) by the reaction of hydrazine hydrate with the appropriate bis(2‐cyanoketene‐S,N‐acetals) was reported. The latter compounds were prepared by treatment of bis(cyanoacetamides) with phenyl isothiocyanate in KOH/EtOH and subsequent alkylation with methyl iodide. The utility of bis(2‐cyanoketene‐S,S‐acetals) as building blocks for novel bis(aminopyrazoles) was also investigated.

Synthesis, structure and properties of N-R-2-(5-(5-methyl-1H-pyrazole-3-yl)-4-phenyl-4H-1,2,4-triazole-3-ylthio)acetamides

Heterocyclic compounds remain the most promising group of compounds, through which the new drugs with characteristic list of properties are successfully created. Examples of this systems are 1,2,4-triazole and pyrazole. The presence in one molecule structure of fragments of two different azaheterocycles is synthetically interesting and allows increasing the probability to obtain biologically active substance with a wide spectrum of action. The aim of the work was to optimize the synthesis conditions and investigate the properties of N-R-2-(5-(5-methyl-1 H -pyrazole-3-yl)-4-phenyl-4 H -1,2,4-triazole-3-ylthio)acetamides in case of change of chemical process conditions. Methods and results. Ethyl 5-methyl-1 H -pyrazole-3-carboxylate, which was obtained by known techniques using acetone, diethyl oxalate, sodium methoxide, followed by hydrazine hydrate in equivalent amount, was used as the key starting reagent. The resulting ethyl 5-methyl-1 H -pyrazole-3-carboxylate was used to carry out hydrazinolysis reactions and nucleophilic addition of phenyl isothiocyanate with subsequent alkaline heterocyclicization. The synthesized 5-(5-methyl-1 H -pyrazol-3-yl)-4-phenyl-4 H -1,2,4-triazole-3-thiole was used in alkylation reactions with promising reagents for the design of pharmacophoric fragments. The products of such reaction are N -R-2-(5-(5-methyl-1 H -pyrazole-3-yl)-4-phenyl-4 H -1,2,4-triazole-3-ylthio)acetamides. The structure of the resulting compounds was confirmed by elemental analysis, 1 H NMR spectroscopy, IR spectrophotometry. The individuality of the substances was determined by thin-layer chromatography and chromatographic mass spectrometry. For synthesized compounds, preliminary screening was performed using the PASS On-line ® software and molecular docking. Conclusions. N -R-2-5-(5-methyl-1 H -pyrazole-3-yl)-4-phenyl-4 H -1,2,4-triazole-3-ylthio)acetamides are obtained with high yields and purity, their properties are investigated.

Access to Metal-Bridged Osmathiazine Derivatives by a Formal [4+2] Cyclization.

Treatment of osmacyclopentadiene derivatives 1 with phenyl or isopropyl isothiocyanate gave the fused five and six-membered osmacycles 2-5 by a formal [4+2] cyclization. The facile protonation of the newly generated exocyclic imine in complexes 2-5 afforded conjugation-extended osmacycle derivatives 6-9. Compounds 2-9 each contain two main-group heteroatoms (N and S) in the fused six-membered ring located at the ortho (for S) and para (for N) positions relative to the osmium centre; these species can be regarded as rare osma-1,3-thiazine derivatives and represent the first fused metallathiazine derivatives. In contrast to the non-planar organic 6H-1,3-thiazine, nearly coplanar metallathiazines 8 and 9 can be achieved by tuning the groups on the two nitrogen atoms. These unique metal-bridged osma-1,3-thiazine derivatives exhibit remarkable stabilities, broad spectral absorptions spanning the visible spectra, and considerable photothermal properties, which suggests their potential applications in material science.

Microwave Assisted Synthesis, Characterization and Biological Study of Some Chalcone Compounds Derived from Phenyl Isothiocyanate

Chalcones are synthesized by Claisen-Schmidt condensation, which involves cross-aldol condensation of appropriate aldehydes and ketones by base catalyzed reaction, the new chalcone derivatives synthesized by the reaction aldehyde with their compounds. By microwave assisted synthesis, a considerable increase in the reaction rate has been observed and that too, with better yields. M.P., TLC, CHN, FTIR, NMR and MS spectroscopy has characterized all the synthesized compounds. The biological screening data of the synthesized compounds were also studied. Keywords : microwave, chalcone, antibacterial. DOI : 10.7176/CMR/11-3-05 Publication date :March 31 st 2019

Rotational Spectra and Structures of Phenyl Isocyanate and Phenyl Isothiocyanate.

The pure rotational spectra of phenyl isocyanate (PhNCO) and phenyl isothiocyanate (PhNCS) were investigated using Fourier transform microwave spectroscopy in the range from 4 to 26 GHz. For each molecule, rotational transitions due to the parent species and nine minor isotopologues including seven 13C, one 15N, and one 18O/34S have been observed in natural abundance. The rm(1) geometries were derived from the resulting sets of rotational constants and are consistent with the equilibrium structures (re) from ab initio calculations performed at the MP2/aug-cc-pVTZ level. NBO and Townes-Dailey analyses were conducted to better understand the electronic structure and geometry of each compound. In the case of PhNCS, the nitrogen atom displays more sp-like character resulting in shorter C-N bonds and a larger CNC angle relative to those of PhNCO.

Synthesis, Docking, and Anticancer Activity of New Thiazole Clubbed Thiophene, Pyridine, or Chromene Scaffolds

2‐Cyanoacetamido‐4‐methylthiazole (1) was utilized as a versatile precursor for the construction of new thiazole clubbed thiazolidine, thiophene, pyridine, or chromene scaffold. The base‐catalyzed addition of 1 to phenyl isothiocyanate followed by subsequent treatment of the produced thiocarbamoyl intermediate with ethyl chloroacetate or chloroacetonitrile furnished the corresponding thiazolyl‐thiazolidine and thiazolyl‐thiophene hybrids. The reactions of compound 1 with chemical reagents, namely, acetylacetone, malononitrile, and/or 2‐(4‐anisylidene)‐malononitrile have been studied and furnished the corresponding thiazole‐pyridine hydrides 8–10. Furthermore, treatment of the precursor 1 with salicylaldehyde, various aryl diazonium chlorides, and/or aromatic aldehydes afforded their corresponding thiazolyl‐chromene hybrid 12, arylhydrazono‐nitriles 13, and unsaturated nitriles 14, respectively. The cytotoxicity of the synthesized compounds was screened against the cell lines HepG2, HCT‐116, and MCF‐7. Compounds 8, 10, and 12 recorded the best results, which was illustrated by molecular docking. Molecular Operating Environment molecular docking calculations carried out here is to rationalize correlation between docking results and biological data of thymidylate synthase (Protein Data Bank code: IHVY) inhibition. Docking has been carried out in the same co‐crystallographic inhibitor binding site to predict if the binding mode of active compounds is analogous to that of native inhibitor.

Synthesis and Transformations of 4-Hydroxy-2-methylquinoline-6-carbohydrazide

A substituted quinoline-6-carbohydrazide was synthesized by the reaction of ethyl 4-hydroxy-2-methylquinoline-6-carboxylate with hydrazine hydrate. The quinoline-6-carbohydrazide was reacted with phenyl isothiocyanate to obtain the corresponding phenylhydrazinecarbotioamide. The intramolecular cyclization of the latter in alkaline and acidic media gave quinolyl-substituted triazole and thiadiazole. The reaction of the quinoline-6-carbohydrazide with carbon disulfide in an alkaline media yielded a quinolyl-substituted 1,3,4-oxadiazole, and the reactions of the same reagent with substituted benzaldehydes gave N′-(substituted benzylidene)quinoline-6-carbohydrazides.

New 1,3,4‐Thiadiazole Derivatives: Synthesis, Characterization, and Antimicrobial Activity

In the present study, 2,5‐bis(mercapto‐acetichydrazide)‐1,3,4‐thiadiazole (1) was utilized by different reagents, namely, ethoxymethylene malononitrile, ethoxymethylene ethyl cyanoacetate, triethyl orthoformate, phenyl isothiocyanate, carbon disulfide, isatin, acetophenone, cyclohexanone, different aldehydes, and different anhydrides, to yield a new series of 2,5‐disubstituted‐1,3,4‐thiadiazoles 2–18. The chemical structure of these products was characterized by the spectral data IR, 1H‐NMR, 13C‐NMR, MS, and elemental analysis. All the synthesized compounds were screened for their antibacterial activity.

Metabolic profile analysis of free amino acids in experimental autoimmune uveoretinitis rat plasma.

To determine the differences of amino acid (AA) levels in experimental autoimmune uveoretinitis (EAU). AA analysis of the plasma samples in EAU rats induced by interphotoreceptor retinoid-binding protein emulsion were performed with high performance liquid chromatography (HPLC) and phenylisothiocyanate (PITC) pre-column derivation methods were performed. Using partial least squares discriminant analysis (PLS-DA), the potential biomarkers were identified in EAU rat plasma, and the metabolic pathways related to EAU were further analyzed. The method results showed that linear (r≥0.9957), intra-day reproducible [relative standard deviation (RSD)=0.04%-1.33%], inter-day reproducible (RSD=0.06%-2.07%), repeatability (RSD=0.03%-0.89%), stability (RSD=0.05%-2.48%) and recovery (RSD=1.98%-4.39%), with detection limits of 0.853-11.4 ng/mL. The metabolic profile in EAU rats was different from that in the control groups five AAs concentrations were increased and nine AAs were reduced. Moreover, five metabolic pathways were related to the development of EAU. The developed method is a simple, rapid and convenient for determination of AAs in EAU rat plasma, and these findings will provide a comprehensive insight on the metabolic profiling of the pathological changes in EAU.

Synthesis of Novel Pyrazole Derivatives and Their Tumor Cell Growth Inhibitory Activity.

To find novel antitumor agents, a series of 1H-benzofuro[3,2-c]pyrazole derivatives 4a-e were designed and synthesized. The treatment of 6-methoxybenzofuran-3(2H)-one 3 with LiHMDS in anhydrous tetrahydrofuran (THF) followed by reaction with 3-substitued phenyl isothiocyanate gave the thioamide intermediates, which underwent condensation with hydrazine monohydrate in dioxane/EtOH (1:1) to provide the benzofuropyrazole derivatives 4a–e as well as the unexpected pyrazole derivatives 5a–e. In tumor cell growth inhibitory assay, all the benzofuropyrazole derivatives were not active against the breast tumor MCF-7 cell, only 4a was highly active and more potent than ABT-751 against the leukemia K562 (GI50 = 0.26 μM) and lung tumor A549 cells (GI50 = 0.19 μM), while other benzofuropyrazoles showed very weak inhibitory activity. In contrast, the pyrazoles 5a-e were in general more potent than the benzofuropyrazoles 4a–e. Compound 5a exhibited a similar tendency to that of 4a with high potency against K562 and A549 cells but weak effects on MCF-7 cell. Both pyrazoles 5b and 5e exhibited high inhibitory activities against K562, MCF-7 and A549 cells. The most active compound 5b was much more potent than ABT-751 against K562 and A549 cells with GI50 values of 0.021 and 0.69 μM, respectively. Moreover, 5b was identified as a novel tubulin polymerization inhibitor with an IC50 of 7.30 μM.

Synthesis of tetrahydroindazol-4(5H)one and 7-thione from reaction of functionalized cyclic enaminones with hydrazine

Functionalized enaminones; 3-N-(aryl)amino-1--oxo-cyclohex-2-ene-2-dithiocarboxylates cyclohex-2-en-1-ones and 3-N-(aryl)amino-2-(N-aryl)thioamido-cyclohex-2-en-1-ones were obtained upon reaction of 3-N(aryl)amino-5,5-dimethyl-1-oxo-cyclohex-2-enes with carbon disulfide in presence of sodium hydroxide in DMSO, followed by methylation with dimethyl sulfate or with phenyl and p-bromophenyl isothiocyanates in toluene or under solvent-free condition, respectively. The cyclization of the dithioesters or the thioamides with hydrazine hydrate was accompanied by a displacement of the 3-N- arylamine moiety by a hydrazine group to give 6-hydrazino-4,4-dimethyl-1,3,4,5-tetrahydroindazole-7-thione or 3-N-(aryl)amino-4,5,6,7-tetrahydro-1H-indazole-4(5H)one respectively. Structure of the indazole derivatives formed was further confirmed from their reaction with acetone or p-nitrobenzaldehyde. The new structures were confirmed using 1HNMR, 13CNMR, 2DNMR, DEPT experiments and mass spectra.

Solvent Free Quick Conversion of Mono - And Dicarboxylic Acids into Their Corresponding Anilides with Phenylisothiocyanate

The attraction of isothiocyanates as synthons and as cyclizing agents continues due to their diverse reactions and also due to their easy availability. It would not be out of place to mention that, in comparison to isocyanates (-N=C=O), their Sulphur analogues, isothiocyanates (-N=C=S), are less unpleasant and to some extent less hazardous. The use of isocyanates is drastically limited by the researchers [6] after December 3, 1984 which is the date of Bhopal Disaster held in Union carbide factory, Bhopal, Madhya Pradesh (India) due to the leakage of Methyl isocyanate (MIC) where thousands of people were died due to the toxic effect of MIC (Me-N=C=O). In the present study, a mixture of Phenyl isothiocyanate (2) and monocarboxylic acid (1), in the ratio of 1:1 and Phenyl isothiocyanate (2) and dicarboxylic acid (4) in the ratio of 2:1are taken for condensation reaction by heating at 160°-170°C for 15 minutesunder solvent free condition. Pyridine was used as a catalyst/ base in both the cases. The products obtained were monoanilides (3) and dianilides (5) of mono- and dicarboxylic acids respectively which were recrystallized from aqueous ethanol. Dicarboxylic acids gave unexpected results in some of the cases. For example, Phthalic acid produces N-phenylphthalimide irrespective of the molar ratio of the acid and Phenyl isothiocyanate whereas maleic acid produces neither mono- nor dianilides with Phenyl isothiocyanate under the present condition. A proper systematic investigation was carried out towards the condensation of Phenyl isothiocyanate with mono- and dicarboxylic acids.

In vitro Cytotoxic Evaluation of Some New Synthesized Pyridazine Derivatives

A series of novel pyridazine, pyrazoles, pyrimidines derivatives have been synthesized through the reaction of chloropyridazine (1) with p-phenylenediamine to give compound 2. Diazotization of compound 2 followed by coupling with active methylene compounds namely acetylacetone, ethylcyanoacetate and/or ethylacetoacetate afforded novel hydrazons derivatives (4-6). The resulting hydrazons can have been cyclized using hydrazine hydrate and guanidine gave the corresponding pyrazoles (7-9) and pyimidine (10) derivatives. Reaction of compound 2 with acrylonitrile, aromatic aldehyde, p-chloroacetophenone and phenyl isothiocyanate gave compounds 11, 12a, 12b, 13 and 17, respectively. The latter compounds have been used in synthesis of some heterocyclic compounds. The cytotoxic activity of the most active compounds was assessed in vitro against breast carcinoma cell line (MCF-7), human liver cancer cell line (HEPG2), human colon cancer cell line (HCT). Compounds 4, 8 showed best activity against MCF-7 cell line, compounds 5, 13a showed best activity against HePG2 cell line and compound 10 showed best activity against HCT cell line.

Synthesis and Biological Evaluation of Novel 2-(4-acetyl-3-methyl- 5-(arylamino) thiophen-2-yl)-3-arylquinazolin-4(3H)-one Derivatives as Potential Anti-inflammatory and Antioxidant Agents.

A new series of 2-(4-acetyl-3-methyl-5-(arylamino) thiophen-2- yl)-3-arylquinazolin-4(3H)-one derivatives (11a-11j) were synthesized from acetyl acetone, phenyl isothiocyanate and 2-chloromethyl quinazolinone. Due to side effects of Non Steroidal Anti-Inflammatory Drugs (NSAID), an attempt was made to identify the novel tetrasubstituted thiophene lead compound as potential anti-inflammatory and antioxidant agent. Then newly synthesized compounds were characterized by IR spectroscopy, 1H NMR and mass spectrometry. The synthesized compounds were screened for their in vivo anti-inflammatory activity in carrageenan-induced rat hind paw edema model at dose 20mg/kg body weight using diclofenac sodium as a standard drug. The compounds were also evaluated for their in vitro DPPH free radical-scavenging activity and nitric oxide radical scavenging activity at the concentrations of 10, 20, 40, 60, 80 and 100 µg/mL using ascorbic acid as standard drug. The results from carrageenan-induced rat hind paw edema showed that compounds 11e, 11f and 11b show a significant anti-inflammatory activity of 46.61%, 48.94% and 47.04 % protection respectively to inflamed paw but less than diclofenac sodium. Compounds 11h and 11e show good DPPH free radical scavenging and nitric oxide radical scavenging activity, respectively. From results, it was observed that highly substituted thiophene scaffold exhibits anti-inflammatory and antioxidant activity.

Facile Synthesis and Antimicrobial Activity of 5‐Amino‐3‐methyl‐1‐phenyl‐1H‐thieno[3,2‐c]pyrazole‐6‐carbonitrile and Their Derivatives

5‐Amino‐thieno[3,2‐c]pyrazole derivative 2 was prepared by Gewald reaction in a one‐pot procedure. The amino group of compound 2 like primary aromatic amine formed the diazonium salt when treated with NaNO2/HCl, followed by coupling with different nucleophiles to yield the azo coupling products 3a–d. The reactivity of 5‐amino‐thienopyrazole 2 has been investigated towards different electrophilic reagents such as aromatic aldehydes, alkyl halide, acid chloride, acid anhydride, phenyl isothiocyanate, carbon disulfide, ethyl glycinate, and thioacetamide, which afforded the reaction products 4–14, respectively.

Preliminary X-ray Diffraction Study of Macrophage Migration Inhibitory Factor at Near-Atomic Resolution

Crystals of human macrophage migration inhibitory factor in complexes with phenyl isothiocyanate and tartrate were grown by the capillary counter-diffusion method under microgravity conditions. The preliminary X-ray diffraction study of these complexes was performed at near-atomic resolution (1.16 A).

Efficacy of isothiocyanate-based compounds on different forms of persistent pain.

PurposeCurrent pharmacotherapy for persistent pain related to neuropathy or articular diseases is unsatisfactory, due to the large number of unresponsive patients and side effects. Isothiocyanates (ITCs) are a class of natural or synthetic compounds characterized by the general formula R–NCS. ITCs show antihyperalgesic effects in models of central and peripheral nervous tissue injury and anti-inflammatory properties. The pharmacodynamics are strictly related to the release of the gasotransmitter hydrogen sulfide (H2S) from their moiety. In particular, phenyl ITC (PITC) and 3-carboxyphenyl ITC (3C-PITC) exhibit interesting slow H2S-release properties suitable for treating painful pathology. The aim of the present work was to evaluate the efficacy of PITC and 3C-PITC against mechanical hyperalgesia and spontaneous pain induced by nerve injury and osteoarthritis.MethodsNerve injury and osteoarthritis were induced in rats by ligation of the sciatic nerve (chronic constriction injury) and intra-articular injection of monoiodoacetate, respectively. Behavioral tests were performed 14 days after damage induction.ResultsSingle subcutaneous administrations of PITC, 3C-PITC (4.43 and 13.31 µmol kg−1, respectively) were able to completely reverse hypersensitivity to noxious stimuli in both models of neuropathic and osteoarticular pain. The effect of ITCs was compared with that of NaHS, the prototypical H2S donor, showing similar efficacy and higher potency. ITCs and NaHS also reduced spontaneous pain.ConclusionITCs offer a promising novel approach to counteract persistent, drug-resistant painful pathology.

Synthesis and Structural Characterization of New Benzimidazole Compounds Derived from Electron-Rich Olefins Bearing 1,4- Bisbenzimidazole with CS2, PhNCS, and Chalcogens

In this work, 1,4-bis(3-isopropylbenzimidazolidine-2-ylidene-1-yl)butane (1) and 1,4-bis(3,5(6)-dimethylbenzimidazolidine-2-ylidene-1-yl)butane (2) were reacted with oxygen, sulfur, selenium, tellurium, phenyl isothiocyanate and carbon disulfur. New zwitterionic compounds (9-12) and cyclic urea derivatives of benzimidazole as one (3), thione (4,6), selenone (5,7), tellurone (8) were synthesised from electron-rich olefins. The chemical structure of novel benzimidazole compounds were determined by 1H NMR, 13C NMR, FTIR spectroscopic techniques and elemental analysis.

Novel 4‐Heteroaryl‐antipyrines: Synthesis, Molecular Docking, and Evaluation as Potential Anti‐breast Cancer Agents

Reaction of 1‐[4‐(1,2‐dihydro‐1,5‐dimethyl‐2‐phenyl‐3‐oxo‐3H‐pyrazol‐4‐yl)‐2‐phenylsulfonyl‐1‐ethanone (1) with phenyl isothiocyanate afforded the 4‐(3‐mercapto‐3‐(phenylamino)‐2‐(phenylsulfonyl)acryloyl)‐1,5‐dimethyl‐2‐phenyl‐1H‐pyrazol‐3(2H)‐one (2). Treatment of compound 2 with hydrazonoyl chlorides 3a–h afforded the corresponding1,3,4‐thiadiazole derivatives 5a–h. Cyclocondensation reaction of compound 2 with the appropriate α‐halo‐compounds 6, 8, 10, 12a,b or 14 (ethyl 2‐chloroacetate, chloroacetonitrile, 1‐chloropropan‐2‐one, 2‐bromo‐1‐phenylethanone, 2‐bromo‐1‐p‐tolylethanone, and 2‐bromoacetyl‐3H‐benzo [f]chromen‐3‐one) afforded the 1,3‐thiazole derivatives 7, 9, 11, 13a,b, and 15, respectively. Coupling of the ketosulphone 1 with the appropriate diazotized 4H‐1,2,4‐triazol‐3‐amine 16 and 2‐aminobenzimidazole 19 afforded triazolo[5,1‐c][1, 2, 4]triazine 18 and benzo[4,5]imidazo[2,1‐c][1, 2, 4]triazine 21, respectively. The structures of the synthesized compounds were confirmed on the basis of their elemental analysis and spectral data and evaluated as potential anti‐breast cancer agents. Moreover, the computational studies using MOE 2014.09 software are confirming the results in biological activity.