Abstract: The invention relates to a process for the synthesis of monochloramine by reaction of an ammonium chloride solution with a sodium hypochlorite solution. The sodium hypochlorite solution is basified beforehand with an inorganic base and the ratio of the concentration of ammonium chloride in the reaction medium to the concentration of sodium hypochlorite in the reaction medium is between 1 and 1.5. This ratio is preferably equal to 1.1.

Abstract: 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° C. and 120° C.

Abstract: The invention relates to a process for the synthesis of aryl alkyl monoethers by reaction of a phenol compound, comprising one or more hydroxyl groups attached to the aromatic system, and of a dialkyl carbonate. It is a solvent-free process carried out at a pressure of between 0.93×105 Pa and 1.07×105 Pa, at a temperature of between 100° C. and 200° C., and in the presence of a catalyst chosen from the group consisting of alkaline carbonates and alkaline hydroxides. The dialkyl carbonate is added gradually to the reaction mixture.

Abstract: The invention relates to a process for the synthesis of monochloramine by reaction of an ammonium chloride solution with a sodium hypochlorite solution. The sodium hypochlorite solution is basified beforehand with an inorganic base and the ratio of the concentration of ammonium chloride in the reaction medium to the concentration of sodium hypochlorite in the reaction medium is between 1 and 1.5. This ratio is preferably equal to 1.1.

Abstract: 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° C. and 120° C.

Abstract: The invention relates to a process for the synthesis of aryl alkyl monoethers by reaction of a phenol compound, comprising one or more hydroxyl groups attached to the aromatic system, and of a dialkyl carbonate. It is a solvent-free process carried out at a pressure of between 0.93×105 Pa and 1.07×105 Pa, at a temperature of between 100° C. and 200° C., and in the presence of a catalyst chosen from the group consisting of alkaline carbonates and alkaline hydroxides. The dialkyl carbonate is added gradually to the reaction mixture.

Abstract: Process for the preparation of alkyl chlorides, characterized in that:a) in a first stage a primary mono- or polyhydric alcohol, which has a C.sub.4 -C.sub.30 carbon chain which is saturated, substituted or otherwise by one or more chlorine atoms and branched or otherwise and which may comprise one or more C.sub.5 -C.sub.7 cycloalkyl groups, is reacted with gaseous hydrochloric acid in the absence of catalyst and at a temperature of between 80.degree. C. and 170.degree. C., until the degree of conversion of the alcohol functional groups is equal to or between 60 and 95 mol %, andb) in a second stage phosgene and a catalyst are introduced into the reaction mixture, the catalyst being chosen from the group consisting of hexaalkylguanidinium halides and their hydrohalides, quaternary ammonium halides, quaternary phosphonium halites, pyridine and pyridines substituted by one or more C.sub.1 -C.sub.6 alkyl groups, at a temperature of between 80.degree. C. and 160.degree.C.