反应详情

A hot solution of 10.4 g (0.05 mol) of chromone-3-carbonylchloride in 150 ml of benzene was added over two minutes to a stirred boiling mixture of 3.6 g (0.06 mol) of urea, 100 ml of benzene and two drops of conc. sulfuric acid. The mixture was stirred at reflux for 2 hrs., cooled and filtered; wt 12.3 g; mp 200°-217°. Recrystallization from dimethylformamide gave 63% yield of pure product, mp 247°-250°.

1. temperatureat reflux for 2 hrs
2. temperature, cooled
3. filtrationfiltered
4. customRecrystallization from dimethylformamide