反应详情

In accordance with general method W, 0.80 g (2.42 mmol) of (4) is partly dissolved in 10 ml of sulfolane at 100° C. 15 ml (30.0 g) of polyphosphoric acid are then added to the reaction mixture. Yield: 0.50 g (66.2%); melting point: 171.4° C.