Methanesulfonic Acid → HCID 21997765, compound

Participants

Reaction Steps

6-Chloro-2-anilino-2,3,4,9-tetrahydro-1H-pyrrolo[3,4-b]-quinoline-1,3,9-trione (1.70 g, 5.00 mM) was stirred in methanol (0.85 L), and methanesulfonic acid (85 mL) was added. The yellow suspension was heated to reflux for 16 hours and cooled to room temperature. The resulting mixture was filtered (the filtrate was saved for use in Example 6), and the collected solids were washed with methanol and dried to give 7-chloro-4-hydroxy-3-phenyl-1,2,5,10-tetrahydropyridazino[4,5-b]-quinoline-1,10-dione (0.48 g, 28%) as a yellow powder. This powder was stirred in methanol, and choline hydroxide (45 weight% in methanol, 0.5 mL) was added to give an amber solution. This solution was concentrated and the residue diluted with toluene and concentrated. The residue was diluted with toluene and concentrated two additional times, and the resulting solid residue was triturated with ethanol/toluene (20%, 25 mL) to provide a crystalline solid. The solid was collected to give the title compound (0.49 g, 78%) as a yellow powder, mp 253-257° C.; MS(CI): 340 (M+H).

Provenance & Evidence