反应详情

A mixture of 2-aminopyridine (I1) (1.0 equiv., 27.2 mmol, 3.00 g), 4-nitrophenyl isocyanide (1.1 equiv., 29.9 mmol, 4.40 g), methyl 2-formylbenzoate (1.1 equiv., 29.9 mmol, 4.9 g) and perchloric acid (0.2 equiv., 5.4 mmol, 0.55 g) in methanol was stirred at room temperature overnight. Potassium tert-butoxide (2.2 equiv., 59.8 mmol, 6.7 g) was added and the reaction mixture was further stirred at room temperature for 2 h. Acetic acid (2.0 ml) (or concentrated hydrochloric acid) was added, the resulting precipitate was filtered off and washed with isopropanol and isopropyl ether to give 9-hydroxy-6-(4-nitrophenyl)-pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolin-5(6H)-one (10) (6.80 g, yield=67%, purity (LC)=95%).

1. stirringthe reaction mixture was further stirred at room temperature for 2 h
2. filtrationthe resulting precipitate was filtered off
3. washwashed with isopropanol and isopropyl ether