反应详情

3-Chloro-2-methylpyridine N-oxide may be nitrated with a mixture of nitric acid and sulphuric acids, and the 4-nitropyridine produced successively treated with sodium methoxide, heated in acetic anhydride, purified and deacetylated to give 2-hydroxymethyl-3-chloro-4-methoxypyridine, which may be substituted for 2-hydroxy-3-methoxypyridine in the procedure of Example 1(ii)-(v) to prepare N-cyano-N'-methyl-N"-[2-((3-chloro-4-methoxy-2-pyridyl)methylthio)ethyl]guanidine.