Council of Scientific and Industrial Research

Naina Sharma

Arun Kumar Sinha

Rakesh Kumar

Abhishek Sharma

A microwave-induced process for the preparation of 2-aryl and 2,2-diaryl aldehydes and analogs wherein halohydrin formation and subsequent rearrangement to 2-aryl aldehydes from corresponding aryl alkanols occurs without formation of an intermediate epoxide or use of transition metal catalysts or lewis acids/bases.

Microwave induced single step green synthesis of some novel 2-aryl aldehydes and their analogues

The present invention provides a process for the preparation of some novel 2-aryl and 2,2-diaryl aldehydes and analogues which are privileged intermediates for commercially important nonsteroidal anti-inflammatory drugs including naproxen, flurbiprofen and potent anticancer drug candidates, including phenstatin through a unique single step synthetic methodology utilizing easily available substrates in the form of aryl alkenes as well as environmentally benign aqueous reaction conditions in the form of solvents such as mixtures of water and DMSO or Dioxane and reagents N-bromosuccinimide, N-iodosuccinimide, N-cholorosuccinimide and phase transfer catalyst such as cetyltrimethyl ammonium bromide, N-hexyl ammonium chloride for a reaction time varying from 1 min-30 min, depending upon microwave or conventional heating, without using expensive transition metal catalysts or lewis acids/bases with yield varying from 35-55%, depending upon the solvent and substrate used. The developed method provides a clean and convenient alternative to access a diverse range of medicinally important 2-aryl and 2,2-diaryl aldehyde based scaffolds in lieu of the conventional multistep protocols employing expensive and hazardous transition metal catalysts and lewis acids/bases.

The present invention provides a method for the preparation of some novel multiconjugated 2- or 4-hydroxy substituted stilbenes. The method provides one pot multicomponent approach wherein 3-4 step reaction sequences viz. condensation, decarboxylation and Heck coupling occur simultaneously which results in an enhanced yield of desired products and reduced reaction times.

Growing community of inventors

Himachal Pradesh, India

Naina Sharma