Abstract
An unprecedented attack of the azide functionality by iminium species, generated in situ under Vilsmeier conditions, provided a novel route for the construction of nitrogen heterocycles. Thus, the treatment of 2-azidoacetophenones with Vilsmeier reagent under reflux conditions gave 5-aryloxazole-4-carboxaldehydes. One-pot synthesis of oxazole carboxaldehydes from 2-bromoacetophenones by dehaloazidation-Vilsmeier cyclization reaction sequence provided better yields. The susceptibility of the carbonyl group to undergo chloroformylation at room temperature without affecting the azide function was exploited to provide an attractive scheme for the synthesis of alpha-azido-beta-chlorovinyl azides from phenacyl azides. The synthesis of a series of N-aryl 5-chloro-2-(dimethylamino)imidazole-4-carboxaldehydes was accomplished by the Vilsmeier cyclization of N-aryl-2-azidoacetamides. The possible mechanisms for the reactions are also discussed.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.