It’s only fair to share… 137-45-1 cas 3-Pyrazolin-5-one (8CI) Pyrazol-3(or 5)-ol (6CI,7CI) 1,2-Dihydro-3H-pyrazol-3-one 1,2-Dihydropyrazol-3-one 1H-Pyrazol-3-ol 1H-Pyrazol-5-ol 3-Hydroxypyrazole 3-Pyrazoline-5-one 3-Pyrazolone 4-Pyrazolin-3-one NSC 520837 Pyrazol-3-ol Pyrazol-5-ol Compound 1: Under stirring, to a solution of 5.81 g (50 mmol) of methyl (2E)-3-methoxyacrylate in methanol (5 mL) was hydrazine hydrate (2.75 g, 55 mmol) added and the mixture …