REACTION OF TRICHLOROMETHYLARENES WITH PYRIDINE - A NOVEL SYNTHESIS OF N-(4-PYRIDYL)PYRIDINIUM SALTS AND AROMATIC-ALDEHYDES

We have shown that in reductive condensation of trichloromethylarenes with hydroxylamine and hydrazines in pyridine the reduction stage, inv olving the exchange of one chlorine atom for a hydrogen atom, can proc eed without participation of hydroxylamine or hydrazine via the intera ction of trichloromethylarene with pyridine leading to the formation o f N-[N'-(alpha-chlorobenzyl-4-pyridyl)]pyridinium salts which give aft er hydrolysis N-(4-pyridyl)pyridinium dichloride and respective aromat ic aldehydes in high yields.