Hydrazine hydrate (1:1) → 6,7-dichloro-4-(4-fluoro-3-(4-methoxypiperidine-1-carbonyl)benzyl)phthalazin-1(2H)-one

Participants

Reaction Conditions

Reaction Steps

(Z)-5,6-dichloro-3-(4-fluoro-3-(4-methoxypiperidine-1-carbonyl)benzylidene)isobenzofuran-1(3H)-one (64) (127 mg, 0.28 mmol) was taken up in water (2 mL) and N,N-dimethylformamide (0.500 mL). The resulting mixture was treated with hydrazine hydrate (0.080 mL, 1.65 mmol) and the reaction was heated to 105° C. with stirring for 90 minutes. The reaction mixture was cooled, diluted with water (˜10 mL) and solid collected by suction filtration to afford the crude product, which was purified by flash silica chromatography, eluting with neat ethyl acetate. Pure fractions were evaporated to dryness and the residue triturated under diethyl ether and dried under vacuum to afford the desired material as a white solid (46.0 mg, 35% yield); 1H NMR (400.132 MHz, DMSO) δ 1.30-1.40 (1H, m), 1.44-1.53 (1H, m), 1.72-1.79 (1H, m), 1.87-1.94 (1H, m), 3.04-3.11 (1H, m), 3.29 (3H, s), 3.30-3.40 (2H, m), 3.44-3.49 (1H, m), 3.92-4.00 (1H, m), 4.37 (2H, s), 7.26 (1H, t), 7.38-7.45 (2H, m), 8.29 (1H, s), 8.40 (1H, s), 12.83 (1H, s); m/z (LC-MS, ESI+), RT=2.13 (M+H 464 & 465.9).

Provenance & Evidence