Scheme 2From: Synthesis and fungicidal activity of pyrazole derivatives containing 1,2,3,4-tetrahydroquinolineSynthetic route of intermediates 3o–3p. Reagents and conditions: (a) NH2NH2·H2O (80 %), reflux, 5 h; (b) CH3CH2ONa, CH3CH2OH, reflux, 10 min, then diethyl maleate, reflux, 30 min; (c) POCl3 or POBr3, CH3CN, reflux, 5 h; (d) H2SO4, CH3CN, r.t., 10 min, then K2S2O8, reflux, 4 hBack to article page