title: Unprecedented SnCl2-mediated cyclization of nitro arenes via N-N bond formation.
abstract: [reaction: see text] A mild, efficient, one-pot protocol for the cyclization of nitro-aryl substrates using SnCl(2) has been described. The mechanistic course of the reaction suggests the involvement of a hydroxylamine intermediate leading to an intramolecular cyclization via N-N bond formation. The versatility of the methodology has been demonstrated by using two nitro-aryl substrates derived from dihydroisoquinolines and dihydro-beta-carbolines. The intramolecular cyclization led to the formation of indazoles in high yields and purities.
authors.affiliation: Medicinal Chemistry Division and Molecular and Structural Biology Division, Central Drug Research Institute, Lucknow 226 001, India.
authors.forename: Devesh
authors.initials: D
authors.lastname: Sawant
authors.forename: Rishi
authors.initials: R
authors.lastname: Kumar
authors.forename: Prakas R
authors.initials: PR
authors.lastname: Maulik
authors.forename: Bijoy
authors.initials: B
authors.lastname: Kundu