Utilization of potassium carbonate for the synthesis of 2-(organylsulfonyl)thieno[2,3-b]pyridine derivatives

A novel preparative method for the synthesis of 2-(organylsulfonyl)thieno[2,3- b ]pyridine derivatives has been developed, which allows one to obtain the desired products in a good yield and to shorten the reaction duration. The reaction of 3-cyanopyridine-2(1 H )-thiones with chloromethyl organyl sulfones in the presence of potassium carbonate as the base gave 2-(organylsulfonyl) thieno[2,3- b ]pyridine-3-amines. The same reaction of methyl 4,6-dimethylpyridine- 2(1 H )-thione-3-carboxylate with chloromethyl organyl sulfones resulted in tautomeric mixtures of 4,6-dimethyl-2-(organylsulfonyl)thieno[2,3- b ]pyridine-3-oles and 4,6-dimethyl-2-(organylsulfonyl) thieno[2,3- b ]pyridine-3(2 H )-ones.