反应条件
1: 1.) H2SO4, HNO3; 2.) HCl / 1.) acetic anhydride, -15 deg C, 105 min; 2.) methanol, reflux, 3.5 h 2: pyridine / 24 h / Ambient temperature 3: DBU / pyridine / 1 h / Ambient temperature View Scheme
参考文献
Helvetica Chimica Acta, , vol. 64, # 5 p. 1688 - 1703