Ethanol → 3,4-Dihydroxy-1-methylquinolin-2(1H)-one

Participants

Reaction Steps

A suspension of 1-methyl-3-oximino-quinolin-2,4(1H)-dione (1.7 gm, Formula 1.02, Example 1) and 10% palladium on charcoal (0.5 gm) in a mixture of ethanol (90 ml) and 2N hydrochloric acid (40 ml) was hydrogenated at atmospheric conditions. After 2.5 hrs no further uptake of hydrogen (510 ml) was observed. The reaction mixture was filtered and the solid cake was extracted with hot glacial acetic acid (2×100 ml). The combined filtrates were evaporated under reduced pressure and the produce was crystallized from acetic acid/water to give the title compound (1.6 gm). That the expected product was obtained was confirmed by the spectral data: MS (FAB): m/e 192 (M.+ +1); NMR (DMSO): δ3.66 (s, 3H, CH3 --N), 8.79 (s, 1H, OH), 10.16 (s, 1H, OH) ppm.

Provenance & Evidence