GB877271A - Improvements in or relating to apparatus and process for carrying out liquid phase chemical reactions - Google Patents

Abstract

<FORM:0877271/IV (b)/1> A process for the production of an aryl ester of a phosphorus oxy-acid by reaction between a chloride of the oxy-acid and a phenol with evolution of hydrogen chloride, comprises passing a reacting mixture comprising the phosphorus oxy-acid chloride and the phenol continuously through successive separate reaction zones and passing hydrogen chloride collected under pressure in one zone into and through the reacting mixture in a succeeding zone. Suitable apparatus for carrying out the process is shown in the Figure in which 11 is a mixing vessel to which the reactants and catalyst are fed continuously, the reaction mixture flowing under pressure from the vessel through a heat exchanger 12, where it is heated to reaction temperature, and then through line 13 into the top of a jacketed reaction vessel 16. The latter is divided into a series of compartments 21, 21a, 21b, by horizontal plates 22 and these compartments are connected solely through overflow pipes 23, 23a, 23b open at each end and extending through the plates 22. The reaction mixture fills compartment 21 to the level of the top of the pipe 23 and overflows through the pipe into the next compartment 21a from which it overflows into the next lower compartment 21b and so on. The hydrogen chloride gas formed in the reaction accumulates in the top compartment until its pressure is high enough to force a stream thereof down through pipe 23 into the next lower compartment 21a from which is flows continuously down through successive compartments. The gas is finally withdrawn through an outlet 31 and is discharged through line 36. The reaction is completed in zone 37 below gas outlet 31 and this zone is preferably provided with baffles 38, the liquid reaction mixture being finally withdrawn from the bottom of the vessel and passed through cooler 39. Examples are given for the production of aryl esters from a mixture of cresylic acid, phosphorus oxychloride and magnesium chloride (as catalyst), the cresylic acid used having the approximate composition:- C10 phenols (0.5%), C9 phenols (10.0%), xylenols (72.0%), cresols (14.5%), and phenol (3%). Stannic chloride may also be used as catalyst and other phenols specified include naphthols, ethyl phenols, and chlorphenols.ALSO:A process for the production of an organic compound by a chemical reaction involving the evolution of a by-product gas comprises passing a liquid reacting mixture continously <PICT:0877271/III/1> through successive separate reaction zones, collecting the gaseous by-product under pressure in one zone and passing it through the liquid reacting mixture in a succeeding zone. The successive reaction zones are preferably in the form of superimposed chambers in a single vessel, the reactants being introduced into the topmost chamber and proceeding downwardly through successive chambers. The process is particularly applicable to the manufacture of aryl esters of phosphorus oxy-acids from a halide of a phosphorus oxy-acid and a phenol (see Group IV(b)). Suitable apparatus for this purpose is shown in the Figure in which 11 is a mixing vessel to which the reactants and catalyst are fed continuously, the reaction mixture flowing under pressure from the vessel through a heat exchanger 12, where it is heated to reaction temperature, and then through line 13 into the top of a jacketted reaction vessel 16. The latter is divided into a series of compartments 21, 21a, 21b by horizontal plates 22 and these compartments are connected solely through overflow pipes 23, 23a, 23b open at each end and extending through the plates 22. The reaction mixture fills compartment 21 to the level of the top of the pipe 23 and overflows through the pipe into the next compartment 21a from which it overflows into the next lower compartment 21b and so on. The hydrogen chloride gas formed in the reaction accumulates in the top compartment until its pressure is high enough to force a stream thereof down through pipe 23 into the next lower compartment 21a from which it flows continuously down through successive compartments. The gas in finally withdrawn through an outlet 31 and a cyclone separator 33 and is discharged through line 36. The reaction is completed in zone 37 below the gas outlet 31 and this zone is preferably provided with baffles 38, the liquid reaction mixture being finally withdrawn from the bottom of the vessel and passed through cooler 39.