in xylene T=140°C; 12 h;

1: 56 percent / xylene / 12 h / 140 °C 2: 43 percent / 6M NaOH / ethanol / 48 h 3: 97 percent / pyridine / diethyl ether / 48 h / Ambient temperature 4: 67 percent / diisopropylamine, phosphoryl chloride / CH2Cl2 / a) 1 h, 0 to 5 deg C, b) 1 h, r.t. 5: flash pyrolysis View Scheme