title: Synthesis of γ-azido-β-ureido ketones and their transformation into functionalized pyrrolines and pyrroles via Staudinger/aza-Wittig reaction.
abstract: A simple two-step procedure yielding γ-azido-β-ureido ketones or/and their cyclic isomers, 6-(1-azidoalkyl)-4-hydroxyhexahydropyrimidin-2-ones, has been developed. The synthesis includes three-component condensation of acetals of 2-azidoaldehydes with urea or methylurea and p-toluenesulfinic acid in aqueous formic acid followed by reaction of the obtained N-[(2-azido-1-tosyl)alkyl]ureas with sodium enolates of α-functionalized ketones. The azido ketones or their cyclic isomers are transformed into ureido-substituted Δ(1)- or/and Δ(2)-pyrrolines via Staudinger/aza-Wittig reaction promoted by PPh(3). The obtained pyrrolines are converted into 3-functionalized 1H-pyrroles via elimination of urea under acidic conditions. Convenient one-pot syntheses of 1H-pyrroles starting from N-[(2-azido-1-tosyl)alkyl]ureas or γ-azido-β-ureido ketones have been also developed.
authors.affiliation: Department of Organic Chemistry, Moscow State University of Fine Chemical Technologies, 86 Vernadsky Avenue, 119571 Moscow, Russian Federation.
authors.forename: Anastasia A
authors.initials: AA
authors.lastname: Fesenko
authors.forename: Anatoly D
authors.initials: AD
authors.lastname: Shutalev
mesh_terms: D001386:Azides / Q000138:chemical synthesis* / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry; D014508:Urea / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001386:Azides; D002264:Carboxylic Acids; D007659:Ketones; D011758:Pyrroles; D014508:Urea