GB732405A - Production of nitrohydrocarbons - Google Patents

Abstract

Mononitro substituted aliphatic and cycloaliphatic hydrocarbons are prepared by reacting an aliphatic or cycloaliphatic hydrocarbon with aluminium nitrate in the liquid phase at an elevated temperature, the hydrocarbon and nitrating medium being passed in counterflow through the reaction chamber. The reaction is preferably carried out at an elevated pressure. The reactants may be heated to the required reaction temperature before being passed into the reaction chamber. A suitable form of reaction chamber is a vertical pressure tube in which the nitrating medium is injected at or near the upper end and the hydrocarbon is injected at or near the lower end. Excess heat from the reaction chamber may be absorbed by using more than the theoretical quantity of hydrocarbon, or by injecting a proportion of the cold hydrocarbon into the reaction chamber at various points. Suitable hydrocarbons referred to are propane, n-hexane, n-heptane, octane, dodecane, cyclohexene and methylcyclohexane. Unreacted aluminium nitrate containing basic aluminium compounds may be separated from the reaction products and treated with concentrated nitric acid to form aluminium nitrate suitable for the nitration step. In the example cyclohexane is treated with aluminium nitrate to form nitrocyclohexane together with a small proportion of a dinitrocyclohexane. The Specification refers also to the above process in which the reactants flow in the same direction.