β-Ketoalkylthioacrylic acid derivatives as precursors of thiophenes, thiazolines, and thienopyrimidines

Abstract

Nous avons poursuivi I'Ctude de la rkaction de certains sels sodCs de dCrivCs de I'acide amino-3-cyano-2-thioacrylique avec des dCrivCs halogCnCs. L'action de mtthylcCtones a-halogCnCes a permis d'obtenir dans certaines conditions soit des dCrives d'acide acyl-5-diamino-2,4-thiophene-3-carboxylique soit des ddrives d'acide thiazoline-Axadtique. L'acttylation de certains thiophenes a conduit i la formation de thienopyrimidines.Reactions of sodium salts of substituted 3-amino-2-cyano-3-thioacrylic esters and amides with ahalomethylketones were studied. Conditions were found which led to the synthesis of either 5-acyl-2,4-diaminothiophene-3-carboxylic esters and amides or thiazoline-A'=-acetic esters and amides. Some thiophene-3-carboxamides were also transformed into thienopyrimidines upon acetylation.

Total Synthesis of a Marine Alkaloid—Rigidin E

“…In order to introduce the methyl group to N-3, 2-cyano- N -methylacetamide 11 was synthesized from ethyl cyanoacetate and methylamine in 90% yield [ 18 , 19 ]. Attempts to synthesize key intermediate 14 using the reported three-components reaction of compound 10 , 11 , and 12 proceeded in very low yield and was complicated by undesired byproducts ( Scheme 2 ).…”

Solid Phase and Combinatorial Chemistry in the Heterocyclic Field

“…Based on an aminoalkylurethane linker attached to the Wang resin 157, Zaragoza et al [173] have developed a solid-phase synthesis of substituted 3-aminothiophenes by adapting Lalibert es thiophene synthesis [174,175]. Thus, as shown in Scheme 28.45, Wang resin 157 was primarily treated with 4-nitrophenyl chloroformate (158) in the presence of pyrimidine to give 159 and then reacted with piperazine in DMF to produce 160, which on treatment with cyanoacetic acid afforded 161.…”

Synthesis of functionalized 2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-ones and their recyclization to 2,3-dihydrothieno[3,4-d]pyrimidin-4(1H)-ones

“…On alkylating the latter at the sulfur atom with dimethyl sulfate or benzyl chloride, they furnished 6-alkylthio-5-cyano-2,3-dihydropyrimidin-4(1H)-ones. The neighboring positions of the alkylthio and cyano substituents on the heterocyclic ring enable further heterocyclization of such compounds by the intramolecular Thorp condensation using functionalized alkyl halides as alkylating agents [9]. In the present study, we carry on the research on the chemistry of 2,3-dihydro-1,3-thiazin-4(1H)-ones and develop some new approaches to the synthesis of functionalized partially hydrogenated thienopyrimidines.…”