抄録
Catalytic reduction of various 4-substituted pyridine 1-oxides in neutral medium, with Raney nickel as a catalyst, was carried out at ordinary temperature and pressure. It was thereby found that N-oxide group in these compounds was selectively reduced, irrespective of the substituent in 4-position, and the products were obtained in a good yield of 85∼98%. 4-Nitropyridine 1-oxide afforded 90% of 4-aminopyridine in acetic acid medium and 4-benzyloxypyridine 1-oxide afforded 93% of 4-hydroxypyridine in one step when reduced over a mixed catalyst of palladium-carbon and Raney nickel. It was considered that this process of reduction is the best method for laboratory preparation of 4-substituted pyridines.
