ChemInform Abstract: REACTION OF DIMETHYL SULFOXIDE AND ACETIC ANHYDRIDE WITH 3‐SUBSTITUTED 4‐HYDROXYCOUMARINS

Abstract

Bei der Umsetzung der Hydroxycumarine (I) mit Acetanhydrid in DMSO werden die Spaltprodukte (II) und daneben die kondensierten Cumarine (III) bzw. (IV) erhalten.

Synthesis of some novel dicoumarol derivatives

“…Keeping in view its importance, it was treated with DMSO-acetic anhydride an effective reagent which brings about a range of mechanistically interesting transformations in 4-hydroxycoumarin, dicoumarol, 1 4-acyloxycoumarins 2 and 3-substituted 4-hydroxycounmarins. 3 In continuation with this, we now report structures of the compounds obtained from interaction of substituted dicoumarols (laele) with this reagent and mechanism of their formation.…”

“…Dilution with water afforded a precipitate which was filtered, washed and dried. Crystallization from benzene gave spiran (3). Data [1] benzopyran-4-one (168 mg) was refluxed in 5 g of naphthalene in presence of 100 mg of 10% palladium-charcoal for 5 h. The solution was cooled, diluted with 10 ml benzene, filtered and the filtrate passed through a short column of silica gel to remove naphthalene.…”

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“…Yield(84%),m.p.253-254 0 C [28]. DMSO/Ac 2 O reagent has been found to yield a wide range of products with 4-hydroxy coumarins and its 3-substituted derivatives both of pharmacological and chemical importance under different conditions [29]. Scheme-6 Scheme-7 2.2 DMSO/SO 3 /pyridine DMSO and SO 3 -pyridine complex yields a reagent in presence of triethyl amine that rapidly oxidizes primary and secondary alcohols to corresponding aldehydes and ketones respectively in good yields.…”

Reaction of Dimethyl Sulfoxide with 4-Acyloxycoumarins

“…Dimethyl sulfoxide (DMSO) activated by acetic anhydride brings about a range of transformations in 4-hydroxycoumarins and dicoumarols under varying conditions, whereas DMSO alone has been found to convert 4-acetoxycoumarin (1) into sulphur ylide (2) almost quantitatively at 120 C. [1,2] Because these reactions are temperature dependent, it was worth investigating the interaction of 4-acyloxycoumarins with DMSO at elevated temperatures.…”

“…Such a cyclization has been achieved very successfully during conversion of 3-phenyl-4-hydroxycoumarin to isoflavonone. [2] The structure for the compound is well supported by its IR, NMR, and mass spectra. Though the fine aliphatic protons in the PMR spectrum in the region of 2.86-4.60 are not well resolved, the IR spectrum showing broad carbonyl bands at 1685 cm À1 and mass spectrum showing M þ at 322 and fairly stronger peaks at m=z 174 and 147 are in full agreement with this structure.…”