title: Practical synthesis of functionalized 1,5-disubstituted 1,2,4-triazole derivatives.
abstract: A general approach for the synthesis of 1,5-disubstituted-1,2,4-triazole compounds is described. A series of new oxamide-derived amidine reagents can be accessed in excellent yield with minimal purification necessary. Typically, these amidine reagents are stable crystalline solids and in certain cases were found to exist in a cyclic form as determined by NMR spectroscopy. Under optimized conditions, the direct reaction of these prepared reagents with various hydrazine hydrochloride salts efficiently generates the target triazoles. Both aromatic and aliphatic hydrazines react readily with the amidine reagents under very mild reaction conditions, delivering desired 1,5-disubstituted-1,2,4-triazole derivatives in good yields.
authors.affiliation: Department of Process Research, Merck Reseaerch Laboratories, Merck & Co., Inc., Rahway, New Jersey 07065, United States. yingju_xu@merck.com
authors.forename: Yingju
authors.initials: Y
authors.lastname: Xu
authors.forename: Mark
authors.initials: M
authors.lastname: McLaughlin
authors.forename: Emily N
authors.initials: EN
authors.lastname: Bolton
authors.forename: Robert A
authors.initials: RA
authors.lastname: Reamer
mesh_terms: D000578:Amidines / Q000737:chemistry*; D006834:Hydrazines / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000578:Amidines; D006834:Hydrazines; D007202:Indicators and Reagents; D014230:Triazoles; C029424:hydrazine; C045575:1,2,4-triazole