Synthesis and Reactions of 2,3-Dimethylfuropyridines

Article abstract of DOI:10.1007/BF00807165

A number of substituted 2,3-dimethylfuro<3,2-c>pyridines was synthesized. 3-(4,5-Dimethyl-2-furyl)propenoic acid (1) was converted to the acid azide 2, which in turn was cyclized to give 2,3-dimethyl-5H-furo<3,2-c>pyridine-4-one (3) by heating at 240 deg C in Dowtherm.The pyridone 3 was chlorinated with phosphorus oxychloride to give 4, which was reduced with zinc and acetic acid to 2,3-dimethylfuro<3,2-c>pyridine (5).Treatment of 4 with several secondary heterocyclic amines led to compounds 6a-6c.Reaction of pyridone 3 with phosphorus pentasulfide rendered the thione 7, which was methylated to 8a.The 4-methoxy derivative 8b was obtained from 4 with sodium methoxide. 2,3,5-Trimethylfuro<3,2-c>pyridine-4-one (9) was obtained by reaction of 3 with methyl iodide. - Keywords: 5H-Furo<3,2-c>pyridine-4-ones; 5H-Furo<3,2-c>pyridine-4-thiones; Furo<3,2-c>pyridine