Dulcin

DULCIN, sucrol, phenetol-urea, NH.C,H₁.OC₂H₅.NHCONH₂: colorless needles, melting at 172-173°, intensely sweet taste (200 times sweeter than sugar); soluble in 800 parts cold water and 55 parts boiling water, as well as in 25 parts alcohol. Solubility in oils varies, depending on their content of free acids: in 296 parts yellow and 822 parts white fish oil, in 237 parts castor oil. Dulcin is obtained by heating equivalent amounts of urea and paraphenetidine at 160° for several hours, or by the action of p-phenetidine on phosgene followed by treatment of the resulting intermediate product, C₂H₅OC₆H₄NHCOCl, with ammonia. Proposed by Riedel (J. D. Riedel; 1894) as a sugar substitute for diabetics. The taste of D. is more pleasant than that of saccharin and lacks the 'metallic' aftertaste of the latter. As a sugar substitute, D. is sometimes used to sweeten beverages and confectionery. This sweetening should be considered a harmful adulteration, since in the body D. breaks down into poisonous products (paraaminophenol, phenetidine) that reduce oxyhemoglobin to methemoglobin; these same breakdown products are also formed outside the body by the action of weak acids and alkalis on D. (V. Uglow). As a harmful impurity, D. is not permitted by sanitary laws for sweetening food products and beverages. D. is detected by color reactions: 1) heating a solution of dulcin with mercuric nitrate gives a violet coloration (Jorissen's reaction), 2) after heating a solution of D. with phenol and sulfuric acid, the addition of ammonia produces a blue ring at the interface of the layers (Morpurgo's reaction).