title: Straightforward access to pyrazines, piperazinones, and quinoxalines by reactions of 1,2-diaza-1,3-butadienes with 1,2-diamines under solution, solvent-free, or solid-phase conditions.
abstract: The preparation of tetrahydropyrazines, dihydropyrazines, pyrazines, piperazinones, and quinoxalines by 1,4-addition of 1,2-diamines to 1,2-diaza-1,3-butadienes bearing carboxylate, carboxamide, or phosphorylated groups at the terminal carbon and subsequent internal heterocyclization is described. The solvent-free reaction of carboxylated 1,2-diaza-1,3-butadienes with the same reagents affords piperazinones, while phosphorylated 1,2-diaza-1,3-butadienes yield phosphorylated pyrazines. The solid-phase reaction of polymer-bound 1,2-diaza-1,3-butadienes with 1,2-diamines produces pyrazines.
authors.affiliation: Istituto di Chimica Organica, Università degli Studi di Urbino "Carlo Bo", Via Sasso 75, 61029 Urbino, Italy.
authors.forename: Domitila
authors.initials: D
authors.lastname: Aparicio
authors.forename: Orazio A
authors.initials: OA
authors.lastname: Attanasi
authors.forename: Paolino
authors.initials: P
authors.lastname: Filippone
authors.forename: Roberto
authors.initials: R
authors.lastname: Ignacio
authors.forename: Samuele
authors.initials: S
authors.lastname: Lillini
authors.forename: Fabio
authors.initials: F
authors.lastname: Mantellini
authors.forename: Francisco
authors.initials: F
authors.lastname: Palacios
authors.forename: Jesús M
authors.initials: JM
authors.lastname: de Los Santos
mesh_terms: D000588:Amines / Q000737:chemistry*; D001372:Aza Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D000077489:Piperazine; D010879:Piperazines / Q000737:chemistry*; D011719:Pyrazines / Q000737:chemistry*; D011810:Quinoxalines / Q000737:chemistry*; D012996:Solutions; D012997:Solvents
chemical_list: D000588:Amines; D001372:Aza Compounds; D010879:Piperazines; D011719:Pyrazines; D011810:Quinoxalines; D012996:Solutions; D012997:Solvents; D000077489:Piperazine