Preparation of Quinoline-2,4-dione Functionalized 1,2,3-Triazol-4-ylmethanols, 1,2,3-Triazole-4-carbaldehydes and 1,2,3-Triazole-4-carboxylic Acids

Abstract

(1-(2,4-Dioxo-1,2,3,4-tetrahydroquinolin-3-yl)-1H-1,2,3-triazol-4-yl)methyl acetates substituted on nitrogen atom of quinolinedione moiety with propargyl group or (1-substituted 1H-1,2,3-triazol-4-yl)methyl group, which are available from the appropriate 3-(4-hydroxymethyl-1H-1,2,3-triazol-1-yl)quinoline-2,4(1H,3H)-diones unsubstituted on quinolone nitrogen atom by the previously described procedures, were deacetylated by acidic ethanolysis. Thus obtained primary alcohols, as well as those aforenamed unsubstituted on quinolone nitrogen atom, were oxidized to aldehydes on the one hand with pyridinium chlorochromate (PCC), on the other hand with manganese dioxide, and to carboxylic acids using Jones reagent in acetone. The structures of all prepared compounds were confirmed by ¹H, ¹³C and ¹⁵N NMR spectroscopy. The corresponding resonances were assigned on the basis of the standard 1D and gradient selected 2D NMR experiments (¹H–¹H gs-COSY, ¹H–¹³C gs-HSQC, ¹H–¹³C gs-HMBC) with ¹H–¹⁵N gs-HMBC as a practical tool to determine ¹⁵N NMR chemical shifts at the natural abundance level of ¹⁵N isotope.