作者:Bijoy Kundu、Sanjay K. Singh、Priya Gupta、Srinivas Duggineni
DOI:10.1055/s-2003-42065
日期:——
A versatile method for the solid phase synthesis of quinoxalines has been developed. Polymer-linked 2-nitrophenyl carbamate is treated with α-bromoketones followed by reduction of the nitro group, which underwent spontaneous intramolecular cyclization to afford polymer bound quinoxalines. Finally acidolytic cleavage gave the desired compounds via aerial oxidation in high yields and good purities.
The reaction of o-phenylenediamine (4) with one, two or three equivalents of p-substituted 3-dimethylaminopropiophenone hydrochlorides 5a−e was studied. 4-Aryl-2,3-dihydro-1H-1,5-benzodiazepine derivatives 6a−e were obtained in good yields, along with the 1:2-adducts 7c−e and the unexpected 1:3-adducts rac-8c−e. The type of adduct formed is determined by the molar ratio of the reactants 4 and 5 and