Sulfamic Acid → 6,7-Bis(ethoxycarbonyloxy)chromone-3-carboxylic acid

Participants

Reaction Steps

The compound (1.05 g) obtained in (b) of Experimental Example 1 was dissolved in 31.5 ml of dichloromethane, and a solution of 1.05 g of sulfamic acid in 18.9 ml of water was added at 10° C. with stirring. Then, a solution of 525.6 mg of sodium chlorite in 1.2 ml of water was added. The solution was stirred at the same temperature for 1 hour, and allowed to separate. The dichloromethane layer was washed with water (once) and then with a saturated aqueous solution of sodium chloride (twice), and dried over magnesium sulfate. The solvent was distilled off, and ethyl ether was added to the residue to solidify it. The solidified product was collected by filtration, and dried to afford 950 mg of the desired product.

Provenance & Evidence