title: Ultrasound and microwave assisted synthesis of isoindolo-1,2-diazine: a comparative study.
abstract: A comparative study, ultrasound (US) versus microwave (MW) versus conventional thermal heating (TH), for synthesis of isoindolo-1,2-diazine is described. The reaction pathway is fast, efficient and straight applicable, involving a Huisgen [3+2] dipolar cycloaddition of cycloimmonium ylides to 1,4-naphthoquinone. A feasible reaction mechanism for the obtaining of the fully aromatized tetra- and penta- cyclic isoindolo-1,2-diazine is presented. Under US irradiation the yields are much higher (sometimes substantially, by almost double), the reaction time decreases substantially, the reaction conditions are milder. The use of a generator with a higher nominal power induces higher yields and short reaction times. Overall the use of US it proved to be more efficient than MW or TH. A feasible explication for US efficiency is presented.
authors.affiliation: Al I Cuza University of Iasi, Organic and Biochemistry Department, Iasi, Romania.
authors.forename: Vasilichia
authors.initials: V
authors.lastname: Bejan
authors.forename: Dorina
authors.initials: D
authors.lastname: Mantu
authors.forename: Ionel I
authors.initials: II
authors.lastname: Mangalagiu
mesh_terms: D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D054833:Isoindoles / Q000138:chemical synthesis* / Q000737:chemistry; D008872:Microwaves; D015394:Molecular Structure; D013696:Temperature; D014465:Ultrasonics
chemical_list: D006571:Heterocyclic Compounds; D054833:Isoindoles