Urea → [(4-oxo-4H-1-benzopyran-3-yl)carbonyl]urea
Reaction equation
[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[C:4](=[O:11])[C:3]([C:12](Cl)=[O:13])=[CH:2]1.[NH2:15][C:16]([NH2:18])=[O:17]>C1C=CC=CC=1.S(=O)(=O)(O)O>[O:11]=[C:4]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:10]=2[O:1][CH:2]=[C:3]1[C:12]([NH:15][C:16]([NH2:18])=[O:17])=[O:13]Participants
5
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Procedure
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°.