title: A Dieckmann cyclization route to piperazine-2,5-diones.
abstract: Piperazine-2,5-diones are formed by Dieckmann cyclization (NaH, THF) of substructures of the type CH(2)-N(R)C(O)CH(2)N(R')CO(2)Ph in which the terminal methylene (CH(2)) that is adjacent to nitrogen closes onto the carbonyl group of the phenyl carbamate unit at the other end of the chain. R and R' are alkyl groups, and the terminal methylene is activated by a ketone carbonyl, a nitrile, an ester, or a phosphoryl group. The starting materials are assembled by standard acylation and oxidation processes, starting from a β-(alkylamino)alcohol, an (alkylamino)acetonitrile, an (alkylamino) ester, or an (alkylamino)methyl phosphonate.
authors.affiliation: Chemistry Department, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.
authors.forename: Claude Larrivée
authors.initials: CL
authors.lastname: Aboussafy
authors.forename: Derrick L J
authors.initials: DL
authors.lastname: Clive
mesh_terms: D018360:Crystallography, X-Ray; D003500:Cyclization; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009570:Nitriles / Q000737:chemistry*; D063065:Organophosphonates / Q000737:chemistry*; D000077489:Piperazine; D010879:Piperazines / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D009570:Nitriles; D063065:Organophosphonates; D010879:Piperazines; D000077489:Piperazine