Selective β-Hydroxyethylation at the N-1 Position of a Pyrazolone: Synthesis of Benzyl 1-(β-Hydroxyethyl)-5-methyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carboxylate - Siegmund, Aaron; Retz, Daniel; Xi, Ning; Dominguez, Celia; Bürli, Roland; Liu, Longbin (Synlett, 2008)