Societe Nationale Des Poudres Et Explosifs

Isochem

Denis Souyri

Henri R Delalu

Jacques Berthet

Pierre Le Gars

Julien C Deweerdt

Serge Metge

Loic Lecomte

Jacques Sala

The present invention relates to a process for the selective decomposition of hydrazine in a hydrazine/substituted hydrazine/water mixture. A catalyst chosen from the group consisting of nickel supported on silica/alumina, the nickel-nickel oxide mixture supported on silica/alumina and rhodium supported on carbon is introduced into this mixture and then the mixture is heated at a temperature of between 60&#xb0; C. and 120&#xb0; C.

Process for the selective decomposition of hydrazine in a hydrazine/substituted hydrazine/water mixture

The process according to the invention consists in preparing chlorides of aliphatic or cycloaliphatic hydrocarbons by reacting the corresponding mono- or polyalcohol with phosgene or thionyl chloride in the presence of at least one catalyst chosen from hexasubstituted guanidinium halides and their hydrohalides, optionally grafted via one of their radicals to a silica-based support. The chlorides are quickly obtained with good yields and contain few by-products such as carbonates or chloroformates.

Process for the preparation of aliphatic or cycloaliphatic chlorides

According to the invention, phosgene is reacted with a mercaptan in the presence of a catalyst of the general formula: ##STR1## in which X=O or S and in which R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are, in particular, aliphatic, cycloaliphatic or aromatic groups or a hydrogen atom. The proportion of catalyst is 0.1 to 10 mol %, relative to the mercaptan, and the reaction is carried out at ambient temperature and at atmospheric pressure. The process, which can be made continuous, results in short residence times and in a high yield and a high purity. Thiochloroformates are applied essentially as intermediates for the synthesis of herbicidal compounds.

Process for the manufacture of thiochlorformates

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Toulouse, France

Denis Souyri