title: A closer look at the bromine-lithium exchange with tert-butyllithium in an aryl sulfonamide synthesis.
abstract: A practical protocol for the one-pot synthesis of various aryl sulfonamides, notably of pyridine-core-substituted 7-azaindolyl sulfonamides, is described. A key step is the well-known bromine-lithium exchange reaction of an aryl bromide with tert-butyllithium (t-BuLi). Differing from the common practice to use 2 or more equiv of organolithium, the exact amount of t-BuLi needed for a sufficient exchange reaction is determined for each aryl bromide in a GC-MS-assisted experiment.
authors.affiliation: Department of Nuclear Medicine, University Hospital Münster , Albert-Schweitzer-Campus 1, Building A1, D-48149 Münster, Germany, and Organic Chemistry Institute, University of Münster , Corrensstrasse 40, D-48149 Münster, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Waldmann
authors.forename: Otmar
authors.initials: O
authors.lastname: Schober
authors.forename: Günter
authors.initials: G
authors.lastname: Haufe
authors.forename: Klaus
authors.initials: K
authors.lastname: Kopka
mesh_terms: D001966:Bromine / Q000737:chemistry*; D018020:Lithium Compounds / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D013237:Stereoisomerism; D013449:Sulfonamides / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D018020:Lithium Compounds; D009942:Organometallic Compounds; D011725:Pyridines; D013449:Sulfonamides; C434823:n-butyllithium; D001966:Bromine