Reduction of 3-aminoquinoline-2,4(1H,3H)-diones and deamination of the reaction products

Abstract

3-Aminoquinoline-2,4-diones were stereoselectively reduced with NaBH 4 to give cis-3-amino-3,4-dihydro-4-hydroxyquinolin-2(1H)-ones. Using triphosgene (=bis(trichloromethyl) carbonate), these compounds were converted to 3,3a-dihydrooxazolo[4,5-c]quinoline-2,4(5H,9bH)-diones. The deamination of the reduction products using HNO2 afforded mixtures of several compounds, from which 3-alkyl/aryl-2,3-dihydro-1H-indol-2-ones and their 3-hydroxy and 3-nitro derivatives were isolated as the products of the molecular rearrangement. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.