GB212970A - Improvements in and relating to the manufacture of organic compounds by reactions involving replacement of substituent atoms or groups with liquid reagents - Google Patents

Abstract

212,970. Shannan, W. V., Siderfin, N. E., Adam, W. G., and Gas Light & Coke Co. Dec. 16, 1922. Nitranilines; phenols; dinitrophenol; substitution products, unspecified, obtained by passing reagent over layer of parent compound.-Organic substitution reactions are effected by heating a stationary layer of the one reacting substance with a continuously-moving liquid layer of the other reacting substance or a solution thereof. The moving layer, which will lie above or below the stationary layer according to the specific gravities, should dissolve the reaction product but be practically non-solvent upon the stationary material. The stationary layer is renewed in a continuous or intermittent manner; any conditions of temperature and pressure may be employed, and the reaction product is separated in any way, but when crystallisable is preferably removed by the process of Specification 211.556. The invention relates particularly to the production of o- or p-nitraniline by heating the corresponding nitrochlorbenzene with ammonia solution, and the interaction of chlor-benzenes with caustic soda to produce the corresponding phenols. The reaction vessel comprises a horizontally-disposed coil R<1> in conjunction with a vertically-disposed worm R, both of which are immersed in an oil-bath S heated by gas jets T. In the case of the production of p-nitraniline, a charge of fused p-nitrochlorbenzene is pumped from the feed tank X by the pump U into the coil R' so as to form a layer along the bottom of the coil. Ammonia solution is then drawn from the feed tank X' by the pump U' and is forced slowly over the layer of p-nitrochlorbenzene in the coil R<1>, then up through the worm R where any small quantities of dissolved parent material are completely converted, and the product finally discharged through the nozzle D into the apparatus described in Specification 211,556, in which the p-nitraniline separates in the crystalline form from the accompanying ammonia and ammonium chloride. The pressure in the reaction vessel is determined bv the degree of opening of the outlet valve V. In the case of the treatment of chlorbenzenes with caustic soda of greater specific gravity, the horizontally-disposed coil is superposed over the vertically-disposed worm. The reaction may be conducted at ordinary pressure, as in the manufacture of dinitrophenol from dinitrochlorbenzene.