反应详情

A mixture of 6,7-dihydroxy-2-oxo-2H-1-benzopyran-3-carboxylic acid (110 mg), thionyl chloride (5 mL), and dimethylformamide (one drop) was stirred for 2 hours at room temperature. The excess thionyl chloride was distilled off in vacuo. Benzene (20 mL) was added, followed by vacuum distillation and vacuum drying, to yield 6,7-dihydroxy-2-oxo-2H-1-benzopyran-3-carbonyl chloride.

1. distillationThe excess thionyl chloride was distilled off in vacuo
2. additionBenzene (20 mL) was added
3. distillationfollowed by vacuum distillation and vacuum
4. customdrying