Verfahren zur Herstellung von Hydrazonen

摘要

1,175,839. Preparation of hydrazine derivatives. FISONS INDUSTRIAL CHEMICAL Ltd. 12 April, 1967 [4 May, 1966], No. 19663/66. Heading C2C. Hydrazones of the formula R1R2-N-N = CR3R4 are obtained by reacting chloramine with an amine of the formula R1R2NH and a carbonyl compound of the formula R3R4CO, wherein R1 is H, alkyl, substituted alkyl, alkenyl, aryl, substituted aryl, cycloalkyl or substituted cycloalkyl; R2 is alkyl, substituted alkyl, alkenyl, aryl, substituted aryl, cycloalkyl or substituted cycloalkyl, or where R1 and R2 together with the N-atom form a heterocyclic ring; R3 is hydrogen or alkyl; R4 is alkyl or aryl, or where R3 and R4 together with the carbon atom of the carbonyl group form a cycloaliphatic ring, the reaction being effected in the aqueous phase in the presence of a base. The chloramine reactant, which may be formed in a separate stage or in situ, may be obtained by reacting (1) gaseous Cl 2 with gaseous NH 3 , (2) gaseous Cl 2 with aqueous NH 3 in the presence of a strong base, or (3) aqueous NH 3 with aqueous sodium hypochlorite. The reaction is suitably effected at a temperature of - 20‹ C. to the boiling point of the ketone under the pressure employed at a pH of 12À8-13À5, and the products of the reaction may subsequently be hydrolysed or decomposed to yield substituted hydrazines or salts thereof.