Reaction of N-Heterocycles with Acetylenedicarboxylates in the Presence of N-Alkylisatins or Ninhydrin. Efficient Synthesis of Spiro Compounds

Summary. The 1,3-dipolar intermediates generated by addition of isoquinoline, to dialkyl acetylenedicaboxylates are trapped by N-alkylisatins to produce dialkyl 1,2-dihydro-2-oxo-1-alkylspiro[3H-indol-3,2′-[2H,11bH][1,3]oxazino[2,3-a]isoquinoline]-3′,4′-dicarboxylates in excellent yields. The reaction of isoquinoline, quinoline, or pyridine with dimethyl acetylenedicarboxylate in the presence of ninhydrin led to dimethyl 1,2-dihydro-1,3-dioxospiro[3H-indene-3,2′-[2H,11bH][1,3]oxazino[2,3-a]isoquinoline]-3′,4′-dicarboxylate, dimethyl 1,2-dihydro-1,3-dioxospiro[3H-indene-3,3′[3H,4aH][1,3]oxazino[3,2-a]quinoline]-1,2-dicarboxylate, or dimethyl 1,2-dihydro-1,3-dioxospiro[3H-indene-3,2′-[2H,9aH]pyrido[2,1-b][1,3]oxazino]-3,4-dicarboxylate.     

Efficient synthesis of tetrasubstituted thiophenes by reaction of benzoyl isothiocyanates, ethyl bromopyruvate and enaminones

An efficient synthesis of ethyl 2-(4-acetyl-5-benzoylamino-3-methyl-2-thienyl)-2-oxoacetates is described via reaction between benzoyl isothiocyanates and ethyl bromopyruvate in the presence of enaminones.     

Solvent-free one-pot synthesis of 2-pyridone derivatives

An efficient synthesis of methyl 4-hydroxy-6-oxo-1,6-dihydro-2-pyridine carboxylates is described.This involves three component reactions between primary alkyl amines,malonyl dichloride and methyl propiolates.     

Efficient synthesis of alkyl 2-[2-(arylcarbonylimino)-3-aryl-4-oxo-1, 3-thiazolan-5-ylidene]-acetates

Reaction of 1-aryl-3-arylcarbonylthioureas with dialkyl acetylenedicarboxylates in CH₂Cl₂ at room temperature leads to alkyl 2-[2-(arylcarbonylimino)-3-aryl-4-oxo-1,3-thiazolan-5-ylidene]-acetates in good yields.     

A rapid, four-component synthesis of functionalized thiazoles

An efficient synthesis of 2-(dialkylamino)-4-phenyl)-1,3-thiazol-5-yl)(phenyl)methanone using acid chlorides, secondary amines, 2-bromoacethophenone and ammonium thiocyanate is described.     

Green synthesis and biological activity investigation of new derivatives of spiroisatins

In this research, the synthesis of novel derivatives of spiroisatins in high yields was investigated. These new compounds were synthesized using a multicomponent reaction (MCR) of isatin, malononitrile, acetophenone derivatives, diethyl oxalate, primary amines, and Et₃N in aqueous media. Under similar conditions, spiropyrroloisatins were prepared using MCRs of synthesized spiroistins. The antioxidant activity of newly synthesized spiroisatins is due to having an NH group which was evaluated by two procedures. Also, the antimicrobial activity of newly generated spiroisatins was evaluated by a disk distribution process utilizing two kinds of Gram-negative bacteria and Gram-positive bacteria and bacterial growth was stopped using these compounds. The advantages of this method are short reaction times, high yields of products, and the easy separation of catalyst and product using simple procedures.     

Synthesis of highly functionalized pyrroles from primary amines and activated acetylenes in water

Stable derivatives of pyrroles were prepared using multicomponent reactions of dialkyl acetylenedicarboxylate,primary amine and propiolate in the presence of N-methylimidazole in water at room temperature in good yields.     

Solvent‐free synthesis of 2H‐pyrans: One‐pot reactions of dithiocarbamates,alkyl propiolates,and isocyanides

A novel, convenient, and an efficient approach to the synthesis of 2H‐pyrans has been reported based on the multicomponent reaction. Solvent‐free condition for the reaction of dithiocarbamates, alkyl propiolates and isocyanides lead to the formation of 2H‐pyrans in good yields. In these reactions, synthesis of 2H‐pyrans is possible based on the one‐pot reaction and without using any catalyst. The mild reaction conditions and high yields of the products exhibit the good synthetic advantage of these methods. J. Heterocyclic Chem., lpar;2011).     

Microwave-assisted synthesis of cyclopentanones using the relevant phosphorus ylides

A one-pot synthesis of cyclopentanone derivatives from phosphorus ylide under lab-type microwave assisted methodology was described. The phosphorus ylides were obtained via the reaction of activated acetylenic compounds, ethyl 4-chloroacetoacetate and triphenylphosphine. The structure of phosphorus ylides was assigned by 1H, 13C and 31PNMR. The phosphorus ylides as precursor were crystallized as two enantiomers (R,R) and (S,S) and one of the phosphorus ylide structures was confirmed by single X-ray crystallography.     

Multicomponent reactions of dimethyl methoxymalonate and dialkyl acetylenedicarboxylate in the presence of N-Nucleophiles: one-pot synthesis of 2H-pyridinyl-2-butenedioates in water

Molecular Diversity - An efficient synthesis of 2H-pyridinyl-2-butenedioate derivatives via reaction of dimethyl methoxymalonate and dialkyl acetylenedicarboxylate in the presence of N-nucleophiles...