Because of the reported biological activities of coumarin, 1,3,4-oxadiazole, and acetamides, some new compounds incorporating these moieties were synthesized and evaluated for their biological potential against Gram-positive and Gram-negative bacteria. In the present work, 4-chlororesorcinol (1) and ethyl acetoacetate (2) were mixed in a strong acidic medium to synthesize 6-chloro-7-hydroxy-4-methyl-2-oxo-2H-chromene (3) which was subjected to the intermolecular cyclization after consecutive three steps to synthesize 5-[(6-chloro-4-methyl-2-oxo-2H-chromen-7-yl)oxy]methyl-1,3,4-oxadiazol-2-thiol (6). A series of acetamoyl electrophiles, 8a–o, were synthesized from aralkyl/alkyl/aryl amines, 7a–o, in an aqueous basic medium. The final compounds, 9a–o, were synthesized by the reaction of compounds 6 and 8a–o in DMF/NaH. The synthesized compounds were structurally elucidated by spectral data analysis of IR, 1H-NMR, and EIMS. The most of the synthesized compounds remained moderate to excellent antibacterial agents. The molecules, 9e, 9j, and 9k, were the most efficient ones against all the five bacterial strains taken into account.
In continuance of our search for newer antiproliferative agents we report herein the synthesis and antiproliferative studies of two series ( 5a–j and 10a–c ) of heterocyclic compounds. All the new compounds were characterized by IR, NMR, and mass spectral data. The antiproliferative activity of 10 compounds ( 5a–j ) was carried out on HeLa (cervix cancer cell line) and MDA-MB-435 (melanoma) and LC 50 , TGI, and GI 50 were calculated, while the antiproliferative activity of 3 compounds ( 10a–c ) was carried out against nine different panels of nearly 60 cell lines (NCI-60) according to the National Cancer Institute (NCI US) Protocol at 10 μ M. 1-(7-Hydroxy-4-methyl-2-oxoquinolin-1(2 H )-yl)-3-(4-methoxylphenyl)urea ( 5j ) was found to have antiproliferative activity with GI 50 of 35.1 μ M against HeLa (cervix cancer cell line) and 60.4 μ M against MDA-MB-435 (melanoma), respectively. The compounds 10a , 10b , and 10c showed antiproliferative activity with comparatively higher selectivity towards HOP-92 (Non-Small Cell Lung Cancer) with percent growth inhibitions (GIs) of 34.14, 35.29, and 31.59, respectively.
Simple and efficient synthetic procedures were established for the preparation of new energetic covalent compounds, salts, and protonated ionic liquids based on the readily available antimicrobial agent metronidazole. Some of these materials exhibit the desirable properties of energetic materials and energetic ionic liquids, such as low vapor pressure, low melting point, good chemical and thermal stability, and high energetic content. For each of the relevant compounds prepared, thermal stability was determined by differential scanning calorimetry. Some of these compounds may be considered promising precursors of pharmaceuticals such as antimicrobial, antiparasitic, antifungal, antineoplastic agents, or enzyme inhibitors.
The reaction of 3-aryl-2,4-dicarboethoxy-5-hydroxy-5-methylcyclohexanones 1with benzalacetone, dibenzalacetone, benzalacetophenone, and 4-benzal-1-phenyl-3-methyl pyrazolone has been investigated to give Michael compounds 2-5. hydrolysis of the dioxo derivative 4 afforded1,5-dicarbonyl derivative 6which On condensation with hydrazine and/or substituted hydrazine and hydroxylamine produced1,2-diazepine and 1,2-oxazepine derivatives 7,8 respectively. Reaction of β-Keto ester 1 with 1,3-diphenylacetone afforded 9. The structures of the hitherto unknown compounds have been confirmed by analytical and spectral data. The newly synthesized compounds have been screened to test their antimicrobial and antifungal activity.
The condensation of O-phenylenediamine (OPD) with aryl aldehydes is carried out in acetonitrile using poly(N,N′-dibromo-N-ethylnaphthyl-2,7-disulfonamide) (PBNS) as a novel and heterogeneous catalyst. PBNS has some potential advantages which include ease of separation from the reaction mixture by simple filtration, easy preparation, recoverablility, convenience, and stability under normal condition and also is not dangerous as molecular bromine.
A novel two-step synthesis of 4,5,6,7-tetrahydro-2 H -indazole-3-carbohydrazide has been developed. The library of N ′-arylmethylene-4,5,6,7-tetrahydro-2 H -indazole-3-carbohydrazide was generated by coupling of hydrazide to various aromatic and heterocyclic aldehydes in water media at ambient temperature with great flexibility regarding reaction time and yield.
A novel two-step synthesis of 4,5,6,7-tetrahydro-2 H -indazole-3-carbohydrazide has been developed. The library of N ′-arylmethylene-4,5,6,7-tetrahydro-2 H -indazole-3-carbohydrazide was generated by coupling of hydrazide to various aromatic and heterocyclic aldehydes in water media at ambient temperature with great flexibility regarding reaction time and yield.
An efficient method for the synthesis of N-tert-butyl amides by reaction of nitriles with tert-butyl acetate or tert-butanol is described using oxalic acid dihydrate in solvent-free condition. The result showed that tert-butyl acetate served as a relatively better source of tert-butyl carbocation than tert-butanol.
This paper reports efforts aimed at tuning up the synthesis of a compound library centered on the general template 2-amino-1-phenyl-2-thioxoethanone taking the condensation of ω -haloacetophenone, octasulfur, and morpholine as pilot reaction. Considerations about atomic economy were found extremely precious in selecting the best starting halo-reagent. A one-pot practical method based on use of 2-bromo-1-phenylethanone as substrate and N,N -dimethylformamide as solvent can be easily scaled up to gram amounts (72% yield). Based on this synthetic approach, some more specific examples are reported.
Sodium acetate was applied as an efficient catalyst for the one-pot, three-component condensation reactions consisting of 4-nitrobenzaldehyde 2, malononitrile 3, and thiobarbituric acid 1. Use of nontoxic reaction components, short reaction times, environmental, easy work-up, and high yields are some remarkable advantages of this method. Kinetics and mechanism of the reaction were spectrally studied and the second order rate constant (kovr = k1) was automatically calculated by the standard equations contained within the program. The second order rate constant [Ln(kovr = k1), Ln(kovr = k1)/T] that depended on reciprocal temperature was in good agreement with the Arrhenius and Eyring equations, respectively. This data provided the suitable plots for calculating the activation energy and parameters (Ea, ΔG‡, ΔS‡, and ΔH‡) of the reaction. Furthermore, from studying the effects of solvent, concentration, and catalyst on the reaction rate, useful information was obtained regarding the mechanism. The results showed that the first step of the reaction mechanism is a rate determining step (RDS). The proposed mechanism was confirmed in accordance with the experimental data and also the steady state approximation.
Various 4-bromomethylcoumarins (1a-k) were reacted with methyl salicylate to yield 2-(2-oxo-2H-chromen-4-ylmethoxy)-benzoic acid methyl esters (2a-k). Formations of (3a-k) were achieved by using DBU under microwave irradiation. Structures of all the compounds were established on the basis of their spectral data. All the compounds were tested in vitro for their antimicrobial activity and cell cytotoxicity. All the tested compounds (2b-k) and (3a-k) were shown to be better activity against Staphylococcus aureus than the standard Ciprofloxacin. The compound (3k) (R = 6-OMe) was found to be more potent cytotoxic than the standard 5-fluorouracil.
Chiral ionic liquids, starting from ( S )-proline, have been prepared and evaluated the ability of a chiral catalyst. In Michael reaction of trans - β -nitrostyrene and cyclohexanone, all the reactions were carried out under homogeneous conditions without any solvent except for excess cyclohexanone. The chiral ionic liquid catalyst with the positive charge delocalized bulky pyrrolidinium cation shows excellent yields (up to 92%), diastereoselectivities (syn/anti = 96/4), and enantioselectivities (up to 95% ee) and could be reused at least three times without any loss of its catalytic activity. Such results demonstrated a promising new approach for green and economic chiral synthesis by using the chiral ionic liquids as a chiral catalyst and a chiral medium.
A new class of N-(heteroaryl-substituted)-p-toluenesulphonamides has been synthesized exhibiting antibacterial and antifungal properties. The condensation reaction of p-toluenesulphonyl chloride 1 with appropriate substituted amino pyridines 2a–g in acetone furnished N-(heteroaryl-substituted)-p-toluenesulphonamides 3a–g. These derivatives were characterized by IR, 1H-, and 13C-NMR spectroscopy and were screened in vitro against gram-positive bacteria, gram-negative bacteria, and fungi organisms using agar-diffusion method. Results indicated improved biological activities over reference drugs such as Tetracycline (TCN) and Fluconazole (FLU).
This paper describes an alternative and simple procedure for the synthesis of Ibuprofen using Silica-Supported Preyssler Nanoparticles (H 14 [NaP 5 W 30 O 110 ]/SiO 2 ) (SPNPs), as an eco-friendly, inexpensive, and efficient catalyst. High yields, simplicity of operation, and easy work-up procedure are some advantages of this protocol. Silica-Supported Preyssler Nanoparticles (H 14 [NaP 5 W 30 O 110 ]/SiO 2 ) (SPNPs) offer the advantages of a higher hydrolytic and thermal stability. The salient features of Preyssler’s anion are availability, nontoxicity and reusability. We believe this methodology can find usefulness in organic synthesis.
Copper ferrite nanomaterial (CuFe 2 O 4 ) as reusable heterogeneous initiator in the synthesis of α-aminonitriles. The nanocatalyst is easily recovered and its reusability is recorded. Synthesis of α-aminonitriles derivatives by one-pot reaction of different aldehydes with amines and trimethylsilyl cyanides has been developed using nano copper ferrite (CuFe 2 O 4 ) catalyst under room temperature and green solvent (water as solvent) conditions. α-aminonitriles are important in preparing a wide variety of amino acids, amides, diamines, and nitrogen containing heterocycles.
Copper ferrite nanomaterial CuFe2O4 as reusable heterogeneous initiator in the synthesis of α -aminonitriles. The nanocatalyst is easily recovered and its reusability is recorded. Synthesis of α -aminonitriles derivatives by one-pot reaction of different aldehydes with amines and trimethylsilyl cyanides has been developed using nano copper ferrite CuFe2O4 catalyst under room temperature and green solvent (water as solvent) conditions. α -aminonitriles are important in preparing a wide variety of amino acids, amides, diamines, and nitrogen containing heterocycles.
In this report, synthesis of indenopyrido[2,3- d ]pyrimidine and pyrimido[4,5- b ]quinoline derivatives was investigated via one-pot three-component reaction between 6-amino-2-(alkylthio)-pyrimidin-4(3 H )one, 1,3-indanedione, or 1,3-cyclohexadione and arylaldehyde under ultrasonic irradiation in ethylene glycol as solvent at 65°C. In these reactions fused pyrimidine derivatives were synthesized with high to excellent yields (82–97%) and short reaction times (10–33 min).
This paper describes an alternative and simple procedure for the synthesis of Ibuprofen using Silica-Supported Preyssler Nanoparticles (H 14 [NaP 5 W 30 O 110 ]/SiO 2 ) (SPNPs), as an eco-friendly, inexpensive, and efficient catalyst. High yields, simplicity of operation, and easy work-up procedure are some advantages of this protocol. Silica-Supported Preyssler Nanoparticles (H 14 [NaP 5 W 30 O 110 ]/SiO 2 ) (SPNPs) offer the advantages of a higher hydrolytic and thermal stability. The salient features of Preyssler’s anion are availability, nontoxicity and reusability. We believe this methodology can find usefulness in organic synthesis.
A green and highly efficient method has been developed for the one-pot synthesis of tetrahydrobenzo[b]pyrans via a three-component condensation of aldehydes, 1,3-cyclic diketones, and malononitrile under MW irradiation without using any catalyst and solvent. This transformation presumably occurs by a sequential Knoevenagel condensation, Michael addition, and intramolecular cyclization. Operational simplicity, solvent and catalyst-free conditions, the compatibility with various functional groups, nonchromatographic purification technique, and high yields are the notable advantages of this procedure.
