The keto-dihydrotriazoles or triazolones are obtained by the action of hydrazines on acetyl urethane (A.
CON 3 --> Rï¿½NHï¿½CO 2 C 2 H 5 - R.NH2 azide urethane The secondary amines are prepared, together with the primary and tertiary, by the action of ammonia on the alkyl iodides (see below), or by the hydrolysis of para-nitroso derivatives ` of tertiary aromatic amines, such as para-nitrosodimethylaniline, thus: NOï¿½C 6 H 4 ï¿½N(CH 3) 2 ï¿½ H 2 O = NOï¿½C 6 H 4.
It is prepared by the action of aqueous or alcoholic solutions of the caustic alkalis on the nitroso-acidyl derivatives of methylamine (such, for example, as nitrosomethyl urethane, NO.
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.
#-Aminopyridine is obtained by heating a-pyridyl urethane with fuming hydrochloric acid until no more carbon dioxide is liberated (T.