Eizo Matsumura, Takeo Nashima, F. Ishibashi
Nov 1, 1970
Citations
0
Influential Citations
6
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The reaction of 2-chloromethylpyridine (Ia) and its homologs, 5-ethyl- (Ib), 6-methyl- (Ic), and 4-methyl-2-chloromethylpyridine (Id), with pyridine gave the corresponding 1-(2′-pyridylmethyl)-pyridinium chlorides (II), from which, on heating with dimethyl sulfate, 1-methyl-2-(pyridiniomethyl)-pyridinium salts (III) were obtained. The pyridinium salts were treated with aqueous alkali at a low temperature to yield 1-methyl- (IVa), 5-ethyl-1-methyl- (IVb), 1,6-dimethyl- (IVc), and 1,4-dimethyl-2-pyridone (IVd). The reaction sequence, in combination with the 1-oxidation of 2-picolines and followed by the reaction of the 1-oxides with tosyl chloride to yield 2-chloromethylpyridines, is recommended as a convenient route for the synthesis of 1-methyl-2-pyridones starting with 2-picolines.