反应详情

In 50 ml of hot ethanol was dissolved 1.68 g of 3,6-dimethoxy-o-phenylenediamine. To this solution was gradually added 2.6 g of ethyl 1,4-dihydro-1,4-dioxo-3-methoxy-2-naphthoate under heating with stirring, and the mixture was refluxed for a further 2 hours. The reaction mixture was cooled and the precipitated solid was collected by filtration and recrystallized from benzene to give 3.50 g (92.6% yield) of ethyl 5-hydroxy-8,11-dimethoxybenzo[a]-phenazine-6-carboxylate as red needles, m.p. 290° C. (decomp.), Anal. Calcd.: (%) for C21H18N2O5 ; C, 66.66; H, 4.80; N, 7.40; Found: C, 66.46; H, 4.56; N, 7.53

1. temperatureunder heating
2. temperaturethe mixture was refluxed for a further 2 hours
3. temperatureThe reaction mixture was cooled
4. filtrationthe precipitated solid was collected by filtration
5. customrecrystallized from benzene