Water → 1-(3-Nitrophenyl)-3-oxo-2,3-dihydro-1H-pyrazole-4-carboxylic acid

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Reaction Steps

1-(3-Nitrophenyl)-3-oxo-2,3-dihydro-1H-pyrazole-4-carboxylic acid methyl ester (1.43 g, 0.005 mole) (Taylor A. W. et al, Tetrahedron, 1987, 43 (3), 607-616) in 1,4-dioxane (100 ml) and water (100 ml) was treated with sodium hydroxide (2 g, 0.05 mole) and heated under reflux for 6 hours. The mixture was allowed to cool then concentrated to a small volume in-vacuo, and acidified with concentrated hydrochloric acid. The resulting solid was filtered off and dried in-vacuo to give the title compound as an off-white solid (0.78 g, 60%). M.S. (−ive ion electrospray) m/z 248 ([M−H]−, 25%), 276 (100%).

Provenance & Evidence