Alok Kumar Mitra

Solvent-Free Microwave Enhanced Knoevenagel Condensation of Ethyl Cyanoacetate with Aldehydes

Abstract A high yielding and fast method of Knoevenagel condensation of ethyl cyanoacetate with various aldehydes under microwave irradiation using environment-friendly ammonium acetate in the absence of any solvent is described.

Application of Microwave Irradiation Techniques for the Syntheses of Cinnamic Acids by Doebner Condensation

Abstract The reaction rate of Doebner condensation to achieve cinnamic acids can be dramatically enhanced by irradiating the reaction mixture containing an aromatic aldehyde, malonic acid, pyridine and a trace of piperidine with a commercial microwave oven. Ten cinnamic acids were synthesized within 2-5 min in excellent yields.

New Synthesis of 3-Alkyl Coumarins

Abstract 3-Alkyl coumarins are reported to have anthelmintic, hypnotic and insecticidal properties1–3. Here we report a novel general method for the synthesis of 3-alkylated coumarins. This involves direct C-alkylatioa at the C-3 position of 3-carbethoxy-3,4-dihydrocoumarin followed by hydrolysis, decarboxylation and dehydrogenation of the resulting dihydrocoumarin. 3-Methyl-, 3-ethyl-, 3-n-pro-pyl-, and 3-benzylcoumarins have been synthesised in good yields following the same procedure depicted in the Scheme-1.

Regeneration of Aldehydes from Bisulfite Addition Products in the Solid State using Montmorillonite KSF Clay under Microwave Irradiation

Microwave irradiation of bisulfite addition products with montmorillonite KSF clay under solvent-free conditions provides a fast, efficient and simple method for regeneration of aldehydes in excellent yields.

Microwave-assisted Syntheses of 1,2-Diketones

A comparative study of the conversion of a number of α-hydroxyketones into 1,2-diketones by three oxidants under microwave irradiation is reported.

Microwave-assisted condensation reactions exploiting hexamethylenetetramine as a catalyst under solvent-free conditions

Hexamethylenetetramine has been exploited for the first time successfully as a catalyst for the Doebner reaction and Knoevenagel condensation along with the rate enhancement by microwave irradiation under solvent-free conditions.

Palladium-catalysed Synthesis of 3-Substituted Coumarins

A number of 3-substituted coumarins have been synthesized by palladium-catalysed coupling of 3-bromocoumarin with alkenes, cycloalkenes and alkyne.

Solid State Regeneration of Ketones From Semicarbazones Using Antimony Trichloride Under Microwave Irradiation

Abstract Microwave irradiation of ketosemicarbazones with wet antimony trichloride under solvent-free condition provides a fast, efficient and simple method for the regeneration of ketones in good yields.

A green procedure for the synthesis of cinnamate esters using Aliquat®336

As an effective solid-liquid phase-transfer catalyst as well as an ionic liquid medium Aliquat® 336 has been applied in the synthesis of cinnamate esters under mild green chemistry procedures involving microwave irradiation.

Regeneration of Ketones from Semicarbazones in the Solid State on Wet Silica Supported Sodium Bismuthate under Microwave Irradiation

Microwave irradiation of ketosemicarbazones on wet silica supported sodium bismuthate under environmentally benign solvent-free condition provides a fast, efficient and simple method for regeneration of ketones in good yields.