title: An unprecedented nitrogen elimination reaction: mechanistic studies using 15N-labeled 4-amino-7-benzylpyrrolo[2,3-d][1,2,3]triazine-5-carbonitrile.
abstract: [formula: see text] In the course of our work on novel pyrrolo[2,3-d][1,2,3]triazines we have discovered that 1 undergoes an elimination of nitrogen at 250 degrees C to give 2. We have conducted 15N labeling studies that establish that the loss of N-2 and N-3 from 1 had occurred rather than N-1 and N-2, presumably via a retro Diels-Alder reaction of the imino tautomer 7. This study provides an alternative to the commonly accepted mechanism which involves the loss of N-1 and N-2 via the transient formation of a diazonium compound generated from 4-amino- or 4-oxo-substituted 1,2,3-triazines condensed with carbocycles or heterocycles.
authors.affiliation: Department of Chemistry, College of Literature, Sciences and Arts, University of Michigan, Ann Arbor 48109-1065, USA.
authors.forename: M T
authors.initials: MT
authors.lastname: Migawa
authors.forename: L B
authors.initials: LB
authors.lastname: Townsend
mesh_terms: D007553:Isotope Labeling; D009584:Nitrogen / Q000737:chemistry*; D009590:Nitrogen Radioisotopes; D011758:Pyrroles / Q000737:chemistry*; D014227:Triazines / Q000737:chemistry*
chemical_list: C410524:4-amino-7-benzylpyrrolo(2,3-d)(1,2,3)triazine-5-carbonitrile; D009590:Nitrogen Radioisotopes; D011758:Pyrroles; D014227:Triazines; D009584:Nitrogen