title: A Novel High-Yield Synthesis of Substituted Isoindolequinones.
abstract: The high-yield, general, one-pot synthesis of substituted isoindolequinones, a group of important radiosensitizers which sensitize hypoxic cells to the lethal effect of radiation in cancer radiotherapy, is described. Primary amines react with 2,3-bis[2-(trimethylsilyl)ethynyl]-5,6-dimethylhydroquinone (2) in methanol at room temperature under an inert atmosphere to give substituted isoindolequinones 2-alkyl-1,3,5,6-tetramethylisoindole-4,7-quinone (4) in almost quantitative yields. Moderate yields of 4 are also obtained using 2,3-diethynyl-5,6-dimethylhydroquinone (3) and amines as reactant and solvent under the similar conditions. Tris(2-aminoethyl)amine (TREN) reacts with 2 in MeOH/THF on reflux to produce the isoindolequinone derivative of TREN. Water with 2 on reflux in MeOH forms an isobenzofuranquinone. This indicates that the formation of similar heterocycles from small molecules (e.g., Group VA and VIA hydrides) and 2 is likely. Readily synthesizable starting materials, ease of chromatographic isolation of the product, reaction generality, use of no catalyst, and cost-effective environmentally benign solvents such as MeOH/EtOH make this novel reaction simple and convenient.
authors.affiliation: Department of Chemistry, The University of Akron, Akron, Ohio 44325-3601.
authors.forename: Manisha
authors.initials: M
authors.lastname: Chakraborty
authors.forename: David B.
authors.initials: DB
authors.lastname: McConville
authors.forename: Gerald F.
authors.initials: GF
authors.lastname: Koser
authors.forename: Claire A.
authors.initials: CA
authors.lastname: Tessier
authors.forename: Takeshi
authors.initials: T
authors.lastname: Saito
authors.forename: Peter L.
authors.initials: PL
authors.lastname: Rinaldi
authors.forename: Wiley J.
authors.initials: WJ
authors.lastname: Youngs