triethylamine in ethanol T=50°C; 2.5 h;

1: 98 percent / aq. HNO3 / 1.) RT, 10 min, 2.) 75 deg C, 12 min 2: 67 percent / POCl3, benzyltriethylammonium chloride / acetonitrile / 1.) 40 deg C, 30 min, 2.) reflux, 0.3 h 3: 59 percent / Et3N / ethanol / 2.5 h / 50 °C View Scheme

1: 67 percent / POCl3, benzyltriethylammonium chloride / acetonitrile / 1.) 40 deg C, 30 min, 2.) reflux, 0.3 h 2: 59 percent / Et3N / ethanol / 2.5 h / 50 °C View Scheme