Hydrazine hydrate (1:1) → 4-thiophen-2-yl-2H-phthalazin-1-one

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 2-(thiophene-2-carbonyl)benzoate (0.445 g, 1.81 mmol) and hydrazine hydrate (0.40 mL, 7.1 mmol) in ethanol (6 mL) was stirred at 80° C. overnight, concentrated, and azeotroped with toluene to give the title compound, which was used without purification: 1H NMR (300 MHz, DMSO-d6) δ 12.87 (s, 1H), 8.42-8.28 (m, 1H), 8.23-8.09 (m, 1H), 7.95 (dtd, J=19.0, 7.3, 1.5, 2H), 7.82-7.69 (m, 1H), 7.68-7.55 (m, 1H), 7.33-7.19 (m, 1H), 4.12 (s, OH), 1.91 (s, OH), 1.74 (s, 1H).

Provenance & Evidence