4H-1-Benzopyran-2-carboxylic acid, 4-oxo-, methyl ester → HCID 85040445, compound
Reaction equation
[CH3:1][O:2][C:3]([C:5]1[O:6][C:7]2[C:12]([C:13](=O)[CH:14]=1)=[CH:11][CH:10]=[CH:9][CH:8]=2)=[O:4].[C:16]1([S:22]([N:25]=C=O)(=[O:24])=[O:23])[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1>C(#N)C>[C:16]1([S:22]([N:25]=[C:13]2[C:12]3[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=3)[O:6][C:5]([C:3]([O:2][CH3:1])=[O:4])=[CH:14]2)(=[O:24])=[O:23])[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Combine chromone-2-carboxylic acid methyl ester (0.341 g, 1.66 mmol) and benzenesulfonyl isocyanate (0.365 g, 1.88 mmol) in acetonitrile (5.0 mL) and reflux. After 24 hours, quench the reaction with methanol (1 mL). Concentrate in vacuo and triturate with hexane. Filter to obtain a paste. Recrystallize the paste from methanol to obtain a solid. Recrystallize from methanol to give the title compound as a solid: mp; 144°-146° C.