Tangali R. Ravikumar Naik

An efficient Bi(NO3)3 · 5H2O catalyzed multi component one-pot synthesis of novel Naphthyridines

An efficient and environmentally friendly multicomponent synthesis of substituted 1,8-naphthyridines catalyzed by bismuth(III) nitrate pentahydrate [Bi(NO3)3 · 5H2O] under solvent-free microwave irradiation is described. This procedure has such advantages as short reaction time, high yields, and simple workup. The catalyst could be reused several times, keeping its initial activity recycled reactions.An efficient and environmentally friendly multicomponent synthesis of substituted 1,8-naphthyridines catalyzed by bismuth(III) nitrate pentahydrate [Bi(NO3)3 · 5H2O] under solvent-free microwave irradiation is described. This procedure has such advantages as short reaction time, high yields, and simple workup. The catalyst could be reused several times, keeping its initial activity recycled reactions.

A facile one pot synthesis of some new 2-phenyl-2H-[1,3]thiazino[6,5-b]quinolines under microwave irradiation in solvent free conditions

A series of some new 2-phenyl-2H-[1,3]thiazino[6,5-b]quinolines have been synthesized by the one pot reaction between 2-chloro-3-formylquinolines 1a–i and thiobenzamide using p-TsOH catalyst under microwave irradiation. The procedure is simple, environmentally benign and occurs in good yields. All the new compounds were characterized by elemental analyses, IR, 1H NMR and mass spectral data.

Synthesis of novel 1,5-benzothiazepine[7,6-b]-1, 8-naphthyridines under microwave irradiation via Mannich condensation

A series of novel 1,5-benzothiazepine[7,6-b]-1,8-naphthyridines 3a–j were synthesized by reaction of substituted 2-amino-thiophenol with different substituted 2-chloro-3-formyl-1,8-naphthyridines 1a–d under microwave irradiation and solvent-free condition is described. A judicious choice of the reaction conditions under microwave allowed the final products 3a–j in excellent one-step procedure, whereas experiments under thermal conditions led to 3a–j in lower yields with tedious work-up. The new compounds have been characterized with the assistance of elemental analyses, IR, 1H NMR and mass spectral studies.

p-TsOH Catalysed a Facile One-Pot Synthesis of Some New Substituted [1,2,4]Triazolo[3,4-b][1,3,4] thiadiazepines under Microwave Irradiation in Solvent-Free Conditions

A series of triazolothiadiazepines were synthesized by the reaction of 4-substituted-5-aryl-1,2,4-triazoles and chalcones using p-TsOH as catalyst under solvent-free microwave irradiation conditions. Structure of all the prepared compounds were elucidated by elemental, IR, 1H NMR and mass spectral data.

One-pot Synthesis of 2-seleno-4-methylquinoline

Number of workers has reported the synthesis of condensed fused quinoline derivatives containing selenium atom and studied for their DNA binding, cytotoxic, anticancer and antitumour activities [1,2,3].[...]

Synthesis of Novel 2-Seleno-1,8-naphthyridines Derivatives

Synthesis of series of new 2-phenyl-3-(2-seleno-1,8-naphthyridin-3-yl)-2,3,3a,6-tetrahydro-5H-pyrazolo[3,4-d][1,3]thiazol-5-ones (4a–e) has been reported. The replacement of halogen with NaHSe in the substituted 2-chloro-3-formyl-1,8-naphthyridi afforded 2-seleno-3-formyl-1,8-naphthyridins (2a – e). The reaction between (2a–e) and 1,3-thiazolidine-2,4-dione produced corresponding derivatives of substituted compounds (3a–e), which on reflux with phenyl hydrazine in DMF to generate (4a–e), with good to excellent yields. Structure of newly synthesized compounds were established based on elemental analysis, IR, 1H NMR, and mass spectral data.

Microwave Induced Efficient Synthesis of 2-(1H-benzimidazol-2-ylthio)-4-methylquinoline

chloroquinoline, mercaptobenzimidazole, microwave irradiation Quinoline derivatives posses wide class of biological activities [15]. Mi crowave heating has emerged as apowerful technique to promote a variety of chemical reaction is due to the short reaction time and theoperational simplicity. So number of research paper has appeared proving the synthetic utility of MORE(Microwave-induced Organic Reaction Enhancement) chemistry in routine organic synthesis [6]. 2Chloro4methylquinoline 1 (708 mg, 0.004 mol) and 2mercaptobenzimidazole 2 (600 mg, 0.004 mol)were dissolved in minimum amount of anhydrous DMF. To this (552 mg, 0.004 mol) K

Three-Component One-Pot Synthesis of Novel Benzo(b)1,8-naphthyridines Catalyzed by Bismuth(III) Chloride

A novel and efficient three-component one-pot synthesis of benzo[𝑏]1,8-naphthyridines by 2-amino-4-methylquinoline, aromatic aldehydes, and malononitrile was done. The reaction was catalyzed by an acidic Bismuth(III) chloride, functionalized Bismuth(III) chloride, at room temperature to give various benzo[𝑏]1,8-naphthyridines in high yields. The Bismuth(III) chloride is an environmentally friendly catalyst.

One‐Pot Solvent Free Synthesis and DNA Binding Studies of Thieno[2,3‐b]‐1,8‐Naphthyridines

Abstract With the aim of evaluating interaction between double‐stranded calf thymus (ds)DNA and sulphur containing fused planar rings, the derivatives of 1,8‐naphthyridine containing thiono groups were synthesized by the condensation of 2‐mercapto‐3‐formyl[1,8]naphthyridines using 1‐chloroacetone, 2‐chloroacetamide, chloroaceticacid, and 2‐chloro‐1‐phenylethanone in the presence of anhydrous potassium carbonate as s catalyst under solvent free microwave irradiation. The structures of the compounds were elucidated on the basis of elemental analysis, IR, 1H NMR, and mass spectra. The interaction of thieno[2,3‐b]‐1,8‐naphthyridine‐2‐carboxylic acid (TNC) (3a) with ct‐DNA was studied by UV‐Vis spectrophotometry, viscosity, thermal denaturation, as well as cyclic voltammetry experiments. On binding to DNA, the absorption spectrum underwent bathochromic and hypochromic shifts. Binding parameters, determined from spectrophotometric measurements indicated a binding constant of K b =2.1×106 M−1. The thieno[2,3‐b]‐1,8‐naphthyridine‐2‐carboxylic acid (3a) increases the viscosity of sonicated rod‐like DNA fragments. The binding of TNC to DNA increased the melting temperature by about 4°C. The decrease in peak current heights and shifts of peak potential values are observed by the addition of calf thymus DNA in cyclic voltammetry studies.

Efficient Synthesis of 6-Methyl-4-phenyl-4,7-dihydrotetrazolo[5,1-c][1,2,4]triazine under Solvent-free Conditions

In recent years reaction under solvent free conditions gaining much popularity because under solvent free conditions products obtains in high yield, avoids the use of hazardous and expensive solvents, and makes the manipulation much easier.[...]