Hydrazine hydrate (1:1) → 3-Amino-5-(3,4-dimethoxy-phenyl)-1,5-dihydro-pyrazolo[4,3-c]pyridazin-6-one

Participants

Reaction Conditions

Reaction Steps

The starting chloride (31) (190 mg) was dissolved in 500 μl of ethanol. 5 equivalents of hydrazine hydrate were added and the reaction mixture heated in a sealed tube at 100° C. for 18 hours. HPLC showed the reaction to be complete. The reaction was concentrated to dryness and purified by normal phase SiO2 chromatography eluting with (1:1) ethyl acetate-hexanes going to 100% ethyl acetate to give after drying 25 mg of desired product (I-10) as a solid. MS+: m/e=288.0 (M+H)+, 1H-NMR (500 MHz, MeOH-d4): δ 7.17 (s, 1H), 7.11 (d, 1H), 7.07 (d, 1H), 6.37 (s, 1H), 3.90 (s, 3H), ppm.

Provenance & Evidence