Semicarbazide → [(E)-1-[3-[(5,7-difluoroquinolin-6-yl)methyl]-[1,2,4]triazolo[4,3-b]pyridazin-6-yl]ethylideneamino]urea

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Reaction Conditions

Reaction Steps

A mixture of 1-[3-(5,7-difluoro-quinolin-6-ylmethyl)-[1,2,4]triazolo[4,3-b]pyridazin-6-yl]-ethanone (38 mg, 0.112 mmol), semicarbazide (37.5 mg, 0.336 mmol) and sodium bicarbonate (40 mg, 0.67 mmol) in methanol (3 mL) was stirred at 40° C. for 20 h. LC/MS showed the reaction was complete, and the suspension was filtered. The filtrate cake was washed successively with cold water and methanol, and then dried to afford 36.3 mg (82% yield) of the title compound as white solid. 1H-NMR (400 MHz, DMSO-d6) δ ppm 9.85 (s, 1H), 8.99 (dd, 1H), 8.49 (d, 1H), 8.35 (d, 1H), 8.18 (d, 1H), 7.73 (d, 1H), 7.62 (dd, 1H), 6.82 (s br, 2H), 4.75 (s, 2H), 2.19 (s, 3H). LCMS (method A): [MH]+=397, tR=4.43 min.

Provenance & Evidence