Verfahren zur Herstellung von Pyridiniumsalzen

摘要

The invention comprises pyridinium salts in which the cation has the formula in which R is a hydrogen atom or a C1-C5 alkyl group, one of the groups X and Y is a hydroxyl group and the other is a hydrogen atom or a hydrocarbon group and in which the pyridine and benzene rings may optionally carry additional hydrocarbon groups or the benzene ring may carry an additional group of formula The cation may be, for example, a halide. The new salts may be prepared by reacting pyridine with a suitable aralkyl ester. If desired, the halide ion of a pyridiniumm halide of the above formula may be converted to another cation by reacting the halide with an inorganic salt. In the examples 2 - chloromethyl - 4 - methyl-6-a methylcyclohexyl phenol, prepared by reacting 4 - methyl - 2 - a - methylcyclohexyl phenol with a mixture of hydrochloric acid and paraformaldehyde, is reacted with pyridine to give the corresponding pyridinium salt. A similar method is used for the production of 4-chloromethyl - 2 - methyl - 6 - tert. - butyl phenol, 2-chloromethyl - 4 - methyl - 6 - tert.- butyl phenol, 2 - chloromethyl - 4,6 - ditert. - butyl phenol, 4 - chloromethyl - 2,6 - ditert. - butyl phenol, 4 - chloromethyl - 2,6 - diisopropyl phenol, and 2 - chloromethyl - 4 - methyl - 6 - tert. - octyl phenol which are similarly converted to the corresponding pyridinium salts. The 2-hydroxy-5 - methyl - 3 - (a - methylcyclohexyl) benzyl pyridinium chloride obtained as above is converted to the nitrate, thiosulphate, dithionate and tetrathionate by treating with the corresponding sodium salt.ALSO:Pyridinium salts in which the cation has the formula in which R is a hydrogen atom or a C1-C5 alkyl group, one of the groups X and Y is a hydroxyl group and in which the pyridine and benzene rings may optionally carry additional hydrocarbon groups or the benzene ring may carry an additional group of formula are used as retarders in the vulcanization of natural and synthetic rubbers.