Oxidative cyclisation and methylene insertion in 1,3-indandione derivatives .The mechanistic studies

N D Zargar

doi:10.24297/jac.v13i12.6193

Abstract

Dimethyl sulphoxide activated by acetic-anhydride introduces methylthiomethyl group into phenols,oxidises certain medicinally useful secondary alcohols to their corresponding ketones and brings about oxidative rearrangements in different substrates.It converts 4-hydroxy coumarins and dicoumarols,under varying conditions,to a variety of products of both pharmaceutical and mechanistic interest. When1,3-indandione (1) was interacted with this versatile reagent at water bath temperature,it afforded an ylide (2) and an oxidative cyclisation product (3).However,its interaction with Ar â€“CH = (CN)R,leads to the formation of a mechanistically interesting compound,indeno[1,2-b]-4H pyran(4).  DMSO alone has been used as a reagent and yields a number of products of mechanistic interest with different substrates.When 1,3-indandione (1) was refluxed with DMSO alone at elevated temperature,it results the formation of poly(methylene-bis) 1,3-indandione(5) involving methylene group insertion between different 1,3-indandione moieties.Methylene insertion has also been observed when 1,3-indandione (1) was condensed with formaldehyde in presence of alkali carbonates or primary amines to yield (6)and(7) respectively.

Highlights

Dimethyl sulphoxide acetic anhydride, a versatile reagent has been a subject of reviews and monographs 1-5 with a wide range of chemical applications
1,3-indandione a member of class of 1,3-diketo compounds has been found to yield a number of products of pharmacological importance with different substrates.Its interaction with cyclo pentanone and cyclohexanone furnishes the corresponding 2-cycloalkylidene-1,3-indandione12,shows Michael addition reaction with β-nitrovinyl benzene to give an adduct having fungicidal property which depends upon the type and location of the substituent on aryl residue[13].Several new 3-amino-2,4-dicyano-1-aryl-flourene-9-ones have been synthesized through addition of 1,3-indandione with arylidene malononitriles[14].With 5-bromo-furfural in ethanol it affords 5-bromo furfuryl diindandionyl-methane[15] and furnishes a condensation product with indazoladione[16]
The reaction between 1,3-indandione and DMSO-acetic anhydride reagent when carried out at water bath temperature, reaches completion in 12 hours .Work up through removal of the reagent under vacuum followed by chromatography afforded compounds (2) and (3) The water-soluble, constituent was readily identified as the ylide. (2) on the basis of its m.p. and spectral data which were in full agreement with those reported for this commpound.[17]

Summary

Introduction

A versatile reagent has been a subject of reviews and monographs 1-5 with a wide range of chemical applications. This reagent converrs 4-hydroxy coumarins and its 3substituted derivatives , under varying conditions , to a variety of products of both mechanistic and chemical interest 8,9.

Results

Conclusion