Atochem

Produits Chimiques Ugine Kuhlmann

Jean P Schirmann

Serge Y Delavarenne

Jean Combroux

Francis Weiss

A continuous method for the preparation of concentrated aqueous solutions of hydrazine hydrate from ketazines which are slightly soluble in water, by hydrolysis and distillation under pressure using a distillation column. The column is fed with the ketazine or ketazines and water wherein the water/azine molar ratio ranges between 5 and 7.75.

Process for the preparation of concentrated solutions of hydrazine

A continuous method for the preparation of concentrated aqueous solutions of hydrazine hydrate from concentrated aqueous solutions of acetone azine by a hydrolysis reaction and distillation under pressure in a column. The concentration of the aqueous solution of acetone azine is such that the water/azine molar ratio ranges between 3 and 7.

Preparation of concentrated aqueous solution of hydrazine hydrate

A process is described for the production of azines by contacting in the liquid phase ammonia, hydrogen peroxide and a carbonyl compound, either an aldehyde or a ketone. The reaction takes place in the presence of an amide (I) of a monocarboxylic or dicarboxylic acid, wherein at least one of the ionization constants is below 5 .times. 10.sup.-5, and further in the presence of an inorganic or organic catalyst (II), having the atomic structure H--X--Y.dbd.Z, H representing hydrogen, X and Z representing oxygen or nitrogen and Y representing carbon, nitrogen, phosphorus, arsenic, antimony, sulphur, selenium or tellurium. It is possible for X, Y or Z to carry other substituents, providing valency rules are obeyed. The process is carried out in the presence of the ammonium salt (III) of the carboxylic acid corresponding to the amide (I), at the rate of at least 0.1 mole of the ammonium salt (III) per mole of hydrogen peroxide employed.

Process for making azines

A method is disclosed for preparing symmetrical azines of the formulas ##EQU1## and unsymmetrical azines of the formulas ##EQU2## and mixtures of azines (I), (II) and (IV) and (I), (III) and (V), wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each is a hydrogen atom, a straight chain alkyl radical of from 1 to 12 carbon atoms, a branched chain alkyl radical or unsubstituted or alkyl substituted cycloalkyl radical of from 3 to 12 carbon atoms, a hydrocarbon radical of from 6 to 12 carbon atoms containing a benzene ring; further provided that R.sup.1 and R.sup.2 can be the same or different radicals, R.sup.3 is a radical different from R.sup.1 and R.sup.2 and R.sup.3 and R.sup.4 are radicals different from each other and each is different from R.sup.1 and R.sup.2 ; or R.sup.1 and R.sup.2 or R.sup.1 and R.sup.3 or R.sup.3 and R.sup.4 bonded to the same carbon atom together form an unsubstituted or alkyl substituted alkylene radical of from 3 to 11 carbon atoms, each of the aforesaid radicals being unsubstituted or substituted with one or more radicals which are stable in the medium in which said azines are produced. The method involves reacting in the liquid phase and in the absence of a nitrile, a carbonyl compound of the formula ##EQU3## alone or together with a different carbonyl compound ##EQU4## or ##EQU5## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each has the same meaning defined above, with ammonia and hydrogen peroxide in the presence of an effective amount of at least one catalyst selected from the group consisting of the hydroxides and water soluble organic and inorganic salts of ammonium and the metals of Groups 1a and IIa of the Periodic Table of the Elements, and recovering the azine or mixture of azines from the reaction medium.

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Oullins, France

Jean P Schirmann