Murugan Dinesh

Microwave-assisted clean synthesis of amides via aza-wittig reaction under solvent-free condition

A solvent-free microwave-assisted coupling of phosphazenes with acyl chlorides or carboxylic anhydrides in presence of triethylphosphite has been accomplished resulting in a clean synthesis of amides in good yields. Unlike the prevailing time-consuming solution phase methodologies employing chlorinated solvents, benzene (carcinogenic), etc, the present protocol is an eco friendly, rapid and simple approach.

Water promoted one pot three-component synthesis of tetrazoles

A one pot, three component synthesis of tetrazoles via thiourea has been accomplished in water. Water enhances the solubility of a higher number of components in the three component protocol thus promoting the reaction. The synthesis involves a chemoselective exocyclic reaction, regioselective electrocyclisation and a preferred conformational orientation of the tetrazole side chain which are rationalised based on the relative magnitude of Garbisch angle strain/allylic strains anticipated during the course of the reaction.

A facile, rapid, one-pot regio/stereoselective synthesis of 2-iminothiazolidin-4-ones under solvent/scavenger-free conditions.

Summary A rapid and efficient one pot solvent/scavenger-free protocol for the synthesis of 2-iminothiazolidin-4-ones has been developed. Interestingly, the regio/stereoselective synthesis affords the regioisomeric (Z)-3-alkyl/aryl-2-(2-phenylcyclohex-2-enylimino)thiazolidin-4-one as the sole product in good yield. The selectivities observed have been rationalized based on the relative magnitude of the allylic strains developed during the course of the reaction. This is the first report wherein the impact of allylic strains in directing the regiocyclization has been noted.

Staudinger’s phosphazene as an efficient esterifying reagent

ABSTRACT A new application of Staudinger’s phosphazene as an efficient esterifying reagent is reported. Staudinger’s phosphazene formed in situ by the reaction of organic mono-azide with triphenylphosphine, which is trapped by carboxylic acid, to afford amide exclusively. In contrast, interestingly the same phosphazene behaves in a different way as an efficient esterifying reagent, affording ester under a solvent-free microwave-assisted protocol wherein alcohol is added as the another component in addition to the other reactants. This discovery adds yet another new application of Staudinger’s phosphazene to synthetic chemistry. GRAPHICAL ABSTRACT

Water mediated one-pot synthesis and biological evaluation of 1,2,3-triazolyl-1,4-dihydropyridine hybrids

Design and synthesis of a new series of 1,2,3-triazolyl-1,4-dihydropyridine hybrids (5a–5l) have been accomplished by a one-pot multicomponent reaction of o-propargyl salicylaldehyde/o-propargyl naphthaldehyde, β-keto compounds, ammonium acetate, and organic azides in short reaction times. In vitro antibacterial studies of the newly synthesized hybrids were investigated against four different human pathogens, viz. S. aureus, Proteus mirabilis, E. Coli, and K. Pnemonia, and the results were compared with that of the standard drug, tetracycline. Also, their anti-inflammatory activity was studied against bovine serum albumin (BSA) and compared with that of the reference drug, dichlofenac. Some of the hybrids show good antibacterial and anti-inflammatory activities comparable with that of the reference drugs.Graphical Abstract

Dimethyl 1-(3-hy­droxy-2-iodo-1-phenyl­prop­yl)-1H-1,2,3-triazole-4,5-dicarboxyl­ate

In the title compound, C15H16IN3O5, the central triazole ring is essentially planar (r.m.s deviation = 0.0034 Å) and makes a dihedral angle of 70.14 (5)° with the pendant benzene ring. The mean planes of the two methoxycarbonyl groups make dihedral angles of 22.52 (7) and 40.93 (4)° with the triazole ring. In the crystal, inversion dimers linked by pairs of O—H⋯O hydrogen bonds generate R 2 2(18) loops. The dimers are linked by C—H⋯O and C—H⋯N interactions into sheets lying parallel to the ac plane.