M. Raghavendra

Microwave induced synthesis of thieno[2,3-b]quinoline-2-carboxylic acids and alkyl esters and their antibacterial activity

A series of thieno[2,3-b]quinoline-2-carboxylic acids and alkyl esters, (3a–i) have been synthesized by the condensation of 2-chloro-3-formyl quinolines (1a–c) with thioglycolic acid/alkyl esters under microwave irradiation using anhydrous potassium carbonate. These compounds were characterized by elemental analysis, IR, 1H NMR, and mass spectral studies. Their antibacterial activity was also evaluated.

Microwave Induced One-Pot Synthesis of Some New Thiopyrano[2,3-b]quinolin-2-ones under Solvent-Free Conditions

A series of some new thiopyrano[2,3-b]quinolin-2-one 2a-i have been synthesized by the one pot reaction between 2-mercaptoquinoline-3-carbaldehyde 1a-i and phenoxyacetic acid using TEA catalyst under microwave irradiation in solvent free conditions. The procedure is simple, environmentally benign and occurs in good yields. All the newly synthesized compounds were characterized by elemental analyses, IR, 1H NMR and mass spectral data.

Synthesis of Quinoline-Based Thieno-Seleno-Phenylquinazolinones

The synthesis of quinoline-substituted phenylquinazolinones containing sulfur and selenium is described. These molecules were isolated from a series of reactions of 2-phenyl-4H-3,1-benzoxazin-4-one with 2-chloro, 2-thieno, and 2-selenoquinoline-3-carbaldehyde hydrazones. The structure of the isolated compounds has been elucidated on the basis of IR, 1 H NMR, mass spectral, and elemental analysis data.

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.

A Facile One-Pot Microwave-Induced Synthesis of Some Novel Selenolo[2,3-b]quinoline Derivatives under Solvent-Free Conditions

A rapid, solvent free microwave assisted synthetic strategy has been developed for the synthesis of some selenolo[2,3-b]quinoline derivatives using potassium carbonate by the reaction between 2-seleno-3-formyl-quinolines (2a–d) with 2-chloroacetamide and phenacylbromide. This method found to be very effective, products obtained in high yield, isolation is just treating the reaction mixture with water.

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].[...]

A Facile One-Pot, Microwave-Assisted Synthesis of Some Novel Selenolopyrano[2,3-b]quinolines under Microwave Irradiation Conditions

A series of some novel substituted selenolopyrano[2,3-b]quinolines 2a-c, 3a-c, and 4a-c were prepared from substituted 2-seleno-3-formyl-quinoliness 1a-c, which on reaction with ethyl acetoacetate, diethyl malonate, and ethyl cyanoacetate under microwave irradiation in the presence of piperidine gives the title compounds. The structure of newly synthesized compounds have been evaluated based on analytical, IR, 1H NMR, and mass spectral data.

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.