| Autor: |
Anand D; Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute , Lucknow-226031, India., Patel OP; Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute , Lucknow-226031, India., Maurya RK; Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute , Lucknow-226031, India., Kant R; Molecular and Structural Biology Division, CSIR-Central Drug Research Institute , Lucknow-226031, India., Yadav PP; Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute , Lucknow-226031, India. |
| Abstrakt: |
A phenyliodine(III) diacetate (PIDA)-mediated, highly efficient and tandem approach for the synthesis of aryldiazenylisoxazolo(isothiazolo)arenes from simple 2-amino-N'-arylbenzohydrazides has been developed. The reaction proceeds via formation of (E)-(2-aminoaryl)(aryldiazenyl)methanone as the key intermediate, followed by intramolecular oxidative O-N/S-N bond formation in one pot at room temperature. The quiet different reactivity of the substrate is due to the formation of a diazo intermediate which encounters a nucleophilic attack by carbonyl oxygen on the electrophilic amine to produce isoxazole products, as compared to the previous reportsa,b,4 in which an N-acylnitrenium ion intermediate is intramolecularly trapped by an amine group. |
