Mez (ibid., 1901, 35, p. 242) on substituted ureas, illustrate this point.
Amino derivatives similarly result from thio-ureas and a-haloid ketones; the oxy derivatives from a-sulphocyanoketones by the action of caustic alkali; and the carboxylic acids from chloro-aceto-acetic ester, &c. and thioamides.
3, p. 319.) Ammonia finds a wide application in organic chemistry as a synthetic reagent; it reacts with alkyl iodides to form amines, with esters to form acid amides, with halogen fatty acids to form amino-acids; while it also combines with isocyanic esters to form alkyl ureas and with the mustard oils to form alkyl thioureas.
They are readily hydrolysed by water, and combine with bases to form alkyl ureas, and with alcohols to form carbamic esters.
Alkyl ureas are formed by the action of primary or secondary amines on isocyanic acid or its esters: [[Conh+Nh2r= R Nhc0nh]] 2 i [[Conr+Nhr 2 =Nr 2 Co Nhr]]; by the action of carbonyl chloride on amines: COC12+2NHR2=C0(NR2)2+2HC1; and in the hydrolysis of many ureides.
The symmetrically substituted ureas are generally tasteless, while the asymmetrical derivatives are sweet.