Syntheses of the Ammonium Salts of 7-Carbamate Derivatives of Quercetin

A series of 7-carbamate derivatives of quercetin were synthesized. Using dichlorodiphenylmethane and benzyl bromide to partly protect the hydroxyl groups, the protected quercetin then reacted with amino acid ester isocyanates, deprotection the hydroxyls with hydrogen using a palladium on carbon catalyst, then treating with ammonia gas to give the ammonium salts of 7-carbamate derivatives of quercetin.