A reinvestigation of a chiral phosphoric-acid-catalyzed four-component Hantzsch enantioselective synthesis polyhydroquinolines reported in 2009 is presented. In our hands, when the reaction was performed with fidelity to original report using enantiopure phosphoric acid catalyst, no enantioselectivity observed. Unlike report, results are backed by baseline separation enantiomers HPLC analyses o...

An efficient one pot multi component synthesis of 1, 4-Polyhydroquinoline derivatives through unsymmetrical Hantzsch reaction using lanthanum chloride heptahydrate (LaCl3.7H2O) from an aromatic aldehyde, ethyl acetoacetate, dimedone and ammonium acetate as a nitrogen precursor in ethanol at room temperature is described. In the present work we report lanthanum chloride heptahydrate remarkably n...

Abstract: Thiazole or 1,3-thiazole is a distinct heterocyclic compound which incorporates sulphur and nitrogen atoms. It vital framework present in numerous pharmacologically active compounds, be it of natural origin synthetic nature. Many thiazoles having antitumor antiviral activities, originate from microbes marine organisms. A variety drugs, thiazole group, like antimicrobial sulfathiazole,...

The polymer supported hypochlorite ion is a facile selective oxidizing agent for the oxidation of various alcohols to aldehydes and ketones. Similarly is successfully oxidizes various Hantzsch type 1,4- dihydropyridines to corresponding pyridines.

Hantzsch 1 ,4- dihy&opyridines are rapidly oxidized to the corresponding pyridine derivatives using zinc chlorochromate nonahydrate [Zn(C1CrO ) .9H O] in dichloromethane at room temperature. In addition to aromatization, no loss of the 4- substituent is observed

A continuous-flow asymmetric organocatalytic photocyclization-transfer hydrogenation cascade reaction has been developed. The new protocol allows the synthesis of tetrahydroquinolines from readily available 2-aminochalcones using a combination of photochemistry and asymmetric Brønsted acid catalysis. The photocylization and subsequent reduction was performed with catalytic amount of chiral BINO...

A novel and green approach for efficient and rapid synthesis of biologically active polyhydroquinoline derivatives via unsymmetric Hantzsch reaction using nanorods Vanadatesulfuric acid (VSA NRs) as a new and recyclable catalyst under solvent-free conditions was reported. The catalyst was characterized by FT-IR, XRD, XRF and TEM analysis. The present method offers several advantages such as sim...

In this study, novel condensed 1,4-dihydropyridines bearing cyclopentanone (1-21) or tetrahydrothiophene-1,1-dioxide ring (22-42) with various ester substituents were synthesized via a modified Hantzsch reaction and their calcium channel modulator activities were investigated on isolated rat ileum and rat thoracic aorta. The introduction of a cyclopentanone ring fused to the 1,4-dihydropyridine...