Base-Induced Cyclization of Active Methylene Isocyanides with Xanthate Esters: An Efficient Method for the Synthesis of 5-Alkoxy-4-(tosyl/ethoxycarbonyl)-1,3-thiazoles

Abstract

Sodium hydride-induced cyclization of 1-[(isocyanomethyl)sulfonyl]-4-methylbenzene or ethyl isocyanoacetate with various xanthate esters gave 5-alkoxy-4-tosylthiazoles or ethyl 5-alkoxythiazol-4-ylcarboxylates, respectively, in good to excellent yields. The xanthate ester S-methyl O-phenyl dithiocarbonate gave 5-(methylsulfanyl)-4-tosyl-1,3-thiazole when treated with 1-[(isocyanomethyl)sulfonyl]-4-methylbenzene under similar conditions.

Regioselective Synthesis of 2,4- and 2,5-Disubstituted 1,3-Thiazoles from 2-Oxo-2-(amino)ethanedithioates via Base-Catalyzed Cyclization

“…25 Our interest in developing general methods for the synthesis of pharmaceutically relevant heterocyclic compounds induced us to unveiling a program aiming to establish widely applicable procedures for the direct synthesis of the desired products using dithioates and other intermediates. 26 27 28 29 30 31 32 In the present study, synthesis of 2,4- and 2,5-disubstituted thiazoles, molecular geometry, FMOs, global and local reactive descriptors, MEP, NCI, and docking analysis were studied and reported.…”

An efficient synthesis of mono-, di-, and tri-substituted 1,3-thiazoles employing functionalized thioamides as thiocarbonyl precursors

“…In addition to our on-going work on the synthesis of novel heterocyclic molecules and unique synthetic techniques utilizing a variety of intermediates such as methyl dithiocarboxylates, xanthate esters, and 2-oxo-2-(amino) ethanedithioates, [16][17][18][19][20][21][22][23][24][25] herein, we developed an operationally simple and novel method for the synthesis of mono-, di-and tri-substituted thiazoles using alkyl 2-amino-2-thioxoacetates intermediates.…”

Regioselective Synthesis of 2,5-Disubstituted-1,3,4-thiadiazoles and 1,3,4-Oxadiazoles via Alkyl 2-(Methylthio)-2-thioxoacetates and Alkyl 2-Amino-2-thioxoacetates

“…Our on-going research work aims at the construction of biologically significant small heterocyclic molecules. , We desire to explore the alternative approaches that can overcome the limitations which are described earlier for the synthesis of 1,3,4-thiadiazoles and 1,3,4-oxadiazoles. Here, we developed operationally simplistic and novel methods with diversified substituents via dehydrative and desulfurative condensation reactions using novel alkyl 2-(methylthio)-2-thioxoacetate and alkyl 2-amino-2-thioxoacetate intermediates.…”