GB698741A - Improvements in or relating to the process of producing a mixture of isomeric chloropentenyl ethers - Google Patents

Abstract

A mixture of 5-chloro-3-pentenyl ether and 3-chloro-4-pentenyl ether obtained by reacting at least two moles of butadiene with one mole of chloromethyl ether (see Group IV (b)) on reaction with an inorganic cyanide appears to yield only one dinitrile which on hydrolysis yields a dicarboxylic acid which may be used for the manufacture of alkyd resins. The mixture of isomers may also be reacted with an aqueous solution of an alkali carbonate to yield a mixture of isomeric glycols which react with polycarboxylic acids, including that described above, to form linear polyesters or alkyd resins. The mixture of isomers can also be converted readily into a mixture of isomeric diamines which react with dicarboxylic acids including that described above to form linear polyamides.ALSO:A mixture of 5-chloro-3-pentenyl ether and 3-chloro-4-pentenyl ether is obtained by reacting at least two moles. of butadiene with one mole. of chloromethyl ether at a temperature of 0-50 DEG C. in the presence of a mild Friedel Crafts catalyst such as zinc chloride, mercuric chloride, ferric chloride, bismuth chloride or antimony chloride. If desired the process may be carried out at superatmospheric pressure of up to 100 pounds per square inch. It is preferred to carry out the process in the presence of a solvent especially glacial acetic acid. The two isomers can be separated by fractional distillation, but this is not usually necessary since the mixture of isomers on reacting with an inorganic cyanide appears to yield only one dinitrile which may be hydrolysed to a dicarboxylic acid. The mixture of isomers can also be reacted with an aqueous solution of an alkali carbonate to yield a mixture of the isomeric glycols which or can be converted to a mixture of isomeric diamines. The dicarboxylic acids, glycols and diamines may be used for the production of polyamides and polyesters (see Group IV (a)). An example is given for the production of the isomeric mixture, the reaction being carried out in the presence of zinc chloride using glacial acetic acid as solvent and using 3 moles. of butadiene per mole of chloromethyl ether. It is stated that when various mixtures of the two isomers are treated with a catalytic amount of zinc chloride the two compounds form an equilibrium mixture containing about 85 per cent of 5-chloro-3-pentenyl ether and about 15 per cent of 3-chloro-4-pentenyl ether.