Synthesis and reactions of 3-cyano-6-methoxymethyl-4-methyl-2(1H)-pyridinethione

Abstract

Nucleophilic substitution of the chlorine atom in 2-chloro-3-cyano-6-methoxymethyl-4-methylpyridine 2-Alkylthiopyridines and 3-aminothieno [2,3-b]pyridines are interesting as potential biologically active compounds and synthones for constructing of polycondensed heterocyclic systems [1][2][3]. We previously have demonstrated the advantage of chemically alkylating substituted 3-cyano-2(1H)-pyridinethiones rather than electrochemically thioalkylating 2-halo-3-cyanopyridine [4, 5]. Therefore, on continuing of investigations on the synthesis of substituted 2-thioalkyl-and thieno[2,3-b]pyridines we carried out nucleophilic substitution of the chlorine atom in 4-methyl-6-methoxymethyl-3-cyano-2-chloropyridine by mercapto group and prepared pyridinethione II, which was then alkylated using the standard method [4].

Facilitating Students’ Review of the Chemistry of Nitrogen-Containing Heterocyclic Compounds and Their Characterization through Multistep Synthesis of Thieno[2,3-b]Pyridine Derivatives

“…Yields for the final products were not as high as for the thiolactam 2 , but they were in a good range of 65 to 72% depending on the initial alkyl halide used for this step (Table ). Structures of compounds 5 , 6 , and 8 were confirmed with 1 H NMR in DMSO- d 6 by noting the appearance of primary amino group at 7.00–7.18 ppm and absence of the methylene (CH 2 ) shift at 4 ppm typical for the intermediates 3 , 4 , and 7 . Students’ analysis of the IR spectra of 5 , 6 , and 8 showed the presence of NH 2 peaks and disappearance of the CN stretch of precursor 2 at 2211 cm –1 (Supporting Information).…”

“…A laboratory experiment for the multistep synthesis of thieno­[2,3- b ]­pyridine derivatives was adapted and modified to acquaint upper-division undergraduate organic chemistry students with the synthesis of heterocyclic compounds with fused rings. , Performing multistep syntheses in their undergraduate laboratory allows students to experience authentic organic chemistry research from technical procedures to detailed product analysis as well as performing retrosynthetic calculations. Several successful multistep syntheses have been reported in this journal but our proposed synthesis appears to be the first student laboratory experiment involving the synthesis of thieno­[2,3- b ]­pyridine systems. − This experiment has been successfully used three times by 336 students in our third-year advanced organic chemistry courses.…”

“…pyridine Derivatives Typical Practical Yield for Each Compound Obtained by Students of the methylene (CH 2 ) shift at 4 ppm typical for the intermediates 3, 4, and 7 8. Students' analysis of the IR spectra of 5, 6, and 8 showed the presence of NH 2 peaks and disappearance of the CN stretch of precursor 2 at 2211 cm −1 (Supporting Information).…”