Diethyl ketene, (C2H5)2C :CO, is formed on heating diethylmalonic anhydride (Staudinger, ibid.).
Succinamide, C 2 H 4(CONH2)2, best obtained by the action of ammonia on diethyl succinate, crystallizes in needles which melt at 242243° C., and is soluble in hot water.
For diethyl ether see Ether, and for methyl phenyl ether (anisole) and ethyl phenyl ether (phenetole) see Carbolic Acid.
Wdhler oxidized potassium ferrocyanide to potassium cyanate by fusing it with lead or manganese dioxide, converted this cyanate into ammonium cyanate by adding ammonium sulphate, and this on evaporation gives urea, thus: K 4 Fe(NC)r-->K CNO--->NH4CNO->CO (NH2)2 It may also be prepared by the action of ammonia on carbonyl chloride, diethyl carbonate, chlorcarbonic ester or urethane; by heating ammonium carbamate in a sealed tube to 130-140° C.; by oxidizing potassium cyanide in acid solution with potassium permanganate (E.