反应详情

A solution, cooled to 0° C., of 770 mg (3.51 mmol) of 8-methoxychromancarboxylic acid and 586 mg (3.83 mmol) of 1-hydroxybenzotriazole in 20 ml of anhydrous dichloromethane is treated with 723 mg (3.51 mmol) of dicyclohexylcarbodiimide and stirred for 5 min. A solution of 700 mg (3.19 mmol) of the compound from Example II and 0.88 ml (8.00 mmol) of N-methylmorpholine in 20 ml of dichloromethane is then added dropwise, and the reaction mixture may be stirred at room temperature for 1 h. The resultant urea is then removed by filtration, the filtrate is concentrated in vacuo and the crude product is purified by chromatography on 150 g of silica gel (dichloromethane/methanol 95:5). The product-containing fractions are collected, the solvent is evaporated in vacuo, and the residue is triturated with diethyl ether, filtered off with suction and dried in a high vacuum. 1.24 g (95%) of the title compound are obtained as colourless crystals.

1. stirringthe reaction mixture may be stirred at room temperature for 1 h
2. customThe resultant urea is then removed by filtration
3. concentrationthe filtrate is concentrated in vacuo
4. customthe crude product is purified by chromatography on 150 g of silica gel (dichloromethane/methanol 95:5)
5. customThe product-containing fractions are collected
6. customthe solvent is evaporated in vacuo
7. customthe residue is triturated with diethyl ether
8. filtrationfiltered off with suction
9. customdried in a high vacuum