title: Solvent-free reaction of some 1,2-diaza-1,3-butadienes with phosphites: environmentally friendly access to new diazaphospholes and E-hydrazonophosphonates.
abstract: [structures: see text] The present article describes the reaction between 1,2-diaza-1,3-butadienes and trialkyl phosphites, under an atmosphere of nitrogen and under solvent-free conditions, to give alkyl 3,3-dialkoxy-2H-1,2,3lambda5-diazaphosphole-4-carboxylates that, in turn, are converted into corresponding E-hydrazonophosphonates by treatment with THF:water (95:5). These latter compounds are obtained directly by the reaction of 1,2-diaza-1,3-butadienes with trialkyl phosphites in the presence of air. These compounds are useful for the further preparation of dialkyl (5-methyl-3-oxo-2,3-dihydro-1H-4-pyrazolyl)phosphonates and 2-dialkoxyphosphoryl-1,2,3-thiadiazoles.
authors.affiliation: Istituto di Chimica Organica, Università degli Studi di Urbino Carlo Bo, Via Sasso 75, 61029 Urbino, Italy.
authors.forename: Orazio A
authors.initials: OA
authors.lastname: Attanasi
authors.forename: Graziano
authors.initials: G
authors.lastname: Baccolini
authors.forename: Carla
authors.initials: C
authors.lastname: Boga
authors.forename: Lucia
authors.initials: L
authors.lastname: De Crescentini
authors.forename: Paolino
authors.initials: P
authors.lastname: Filippone
authors.forename: Fabio
authors.initials: F
authors.lastname: Mantellini