title: Scalable, One-Pot, Microwave-Accelerated Tandem Synthesis of Unsymmetrical Urea Derivatives.
abstract: We report a facile, microwave-accelerated, one-pot tandem synthesis of unsymmetrical ureas via a Curtius rearrangement. In this method, one-pot microwave irradiation of commercially available (hetero)aromatic acids and amines in the presence of diphenylphosphoryl azide enabled extremely rapid (1-5 min) construction of an array of unsymmetrical ureas in good to excellent yields. We demonstrate the utility of our method in the efficient, gram-scale synthesis of key biologically active compounds targeting the cannabinoid 1 and α7 nicotinic acetylcholine receptors.
authors.affiliation: Department of Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University , 140 The Fenway, 360 Huntington Avenue, Boston, Massachusetts 02115, United States.
authors.forename: Abhijit R
authors.initials: AR
authors.lastname: Kulkarni
authors.affiliation: Department of Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University , 140 The Fenway, 360 Huntington Avenue, Boston, Massachusetts 02115, United States.
authors.forename: Sumanta
authors.initials: S
authors.lastname: Garai
authors.affiliation: Department of Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University , 140 The Fenway, 360 Huntington Avenue, Boston, Massachusetts 02115, United States.
authors.forename: Ganesh A
authors.identifier: 0000-0002-7468-8819
authors.initials: GA
authors.lastname: Thakur
mesh_terms: D001386:Azides / Q000737:chemistry; D002625:Chemistry, Organic / Q000379:methods*; D008872:Microwaves; D015394:Molecular Structure; D014508:Urea / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D001386:Azides; D014508:Urea; C007523:diphenylphosphorazidate