138212-06-3Relevant academic research and scientific papers
The synthesis of pyrroles and dihydropyrroles by 1,3-dipolar cyclisations of N-arylmethylene[(benzotriazol-1-yl)arylmethyl]amines
Katritzky,Hitchings,Zhao
, p. 863 - 867 (1991)
N-Arylmethylene[(benzotriazol-1-yl)arylmethyl]amines 1 are prepared by the reaction of arylaldehydes, benzotriazole, and ammonia in dry ethanol. Deprotonation of these imines with butyllithium yields N-lithiated azomethine ylides 2 which readily undergo 1,3-dipolar cycloaddition with a large range of dipolarophiles. The cyclisations are regiospecific and generally exhibit high stereoselectivity. Benzotriazolate is eliminated during the course of the reaction, and the method thereby provides a route to 2,5-diaryl substituted pyrroles, 3,4-dihydro-2H-pyrroles and c-ring fused 3,4-dihydro-2H-pyrroles.
