One‐Pot Synthesis of N‐(Imidazo[1,2‐a]pyridin‐3‐yl)‐ and N‐(Imidazo[2,1‐b][1,3]thiazol‐5‐yl)sulfonamides

Abstract

The reaction of 2-aminopyridines or 2-aminothiazole with N-(2,2-dichloro-2-phenylethylidene)arensulfonamides affords the corresponding products of nucleophilic addition to the azomethine group, N-[2,2-dichloro-2-phenyl-1-(heterylamino)ethyl]sulfonamides, in good yields. The latter are easily cyclized to (imidazo[1,2-a]pyridin-3-yl)sulfonamides and (imidazo[2,1-b]thiazol-5-yl)sulfonamides in the presence of [a] A.E. 369 Scheme 4. A tentative route for the formation of imidazo[1,2-a]pyridines 5.www.eurjoc.org

Regioselective reaction of imidazole-2-thiols with N-sulfonylphenyldichloroacetaldimines: en route to novel sulfonylamino-substituted imidazo[2,1-b]thiazoles and thiazolo[3,2-a]benzimidazoles

“…11,[22][23][24] We are engaged in elaboration of approaches to the preparation of annulated imidazole derivatives containing synthetically important pharmacophoric sulfonylamino group. [25][26][27][28] It is a common knowledge that the sulfonamide compounds are intensively employed for drug design. [29][30][31][32] First of all, these are medicinally classical antagonists of folic acid having antimicrobial and antibiotic properties.…”

One-pot regioselective synthesis of new 5-(arylsulfonylamino)imidazo[2,1-b]thiazoles

“…[8][9][10][11][12] In the present work we have studied the reaction of imine 1 with a range of 2-amino-4,5-diarylthiazoles to elaborate a method for the synthesis of sulfonylamino-substituted imidazo [2,1-b]thiazoles.…”

“…Imine 1 reacts with nucleophiles on the carbon atom of the activated azomethine groups, 1,[8][9][10][11] and also can act as a dielectrophile, successively involving the azomethine moiety and polyhalomethyl fragment in the process.…”

“…Thus, these compounds are promising dielectrophiles that can be used as key reagents in the preparation of amidines, 7 biologically active amino acids, 9 and heterocycles. 8,[10][11][12] N-Sulfonyl-substituted phenyldichloroacetaldimines of the type 1 are key representatives of activated electrophilic imines, that are available through previously developed methods based on free-radical reaction of N,N-dichlorosulfonamides with phenylacetylene (Scheme 1). 13,14 Until now, no alternative syntheses to N-(2,2-dichloro-2-phenylethylidene)arenesulfonamides of type 1 have been developed.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] Moreover, besides the carbon atom of azomethine group,-haloimines contain another electrophilic reactive site, namely the carbon atom of the polyhalomethyl group. Thus, these compounds are promising dielectrophiles that can be used as key reagents in the preparation of amidines, 7 biologically active amino acids, 9 and heterocycles.…”