Efficient synthesis of new butenolides by subsequent reactions: application for the synthesis of original iminolactones, bis-iminolactones and bis-lactones

A synthesis of novel bis(aminopyrazoles) by the reaction of hydrazine hydrate with the appropriate bis(2‐cyanoketene‐S,N‐acetals) was reported. The latter compounds were prepared by treatment of bis(cyanoacetamides) with phenyl isothiocyanate in KOH/EtOH and subsequent alkylation with methyl iodide. The utility of bis(2‐cyanoketene‐S,S‐acetals) as building blocks for novel bis(aminopyrazoles) was also investigated.

Section: Resultsmentioning

confidence: 99%

Novel Bis(2‐cyanoketene‐S,S‐/S,N‐acetals): Versatile Precursors for Novel Bis(aminopyrazole) Derivatives

Hebishy

Elgemeie

Elwahy

2019

“…The bis‐cyanoacetamides 3 were chosen as key intermediates to a variety of novel bis‐cyanopyridone derivatives. They can be prepared by cyanoacetylation of the bisamines 1 with ethyl cyanoacetate 2 according to recently reported procedure (Scheme ) .…”

Section: Resultsmentioning

confidence: 99%

New Bis(dihydropyridine‐3,5‐dicarbonitrile) Derivatives: Green Synthesis and Cytotoxic Activity Evaluation

Abdelmoniem

Salaheldin²,

Abdelhamid

et al. 2017

A synthesis of bis(dihydropyridine‐3,5‐dicarbonitrile) by a three‐component reaction of one equivalent of bis‐cyanoacetamides with two equivalents of both arylaldehydes and malononitrile in ethanol‐containing piperidine is reported. Bis‐cyanopyridones could also be obtained by the condensation of bis‐cyanoacetamides with substituted arylidenemalononitriles in the presence of piperidine, chitosan, or montmorillonite as basic catalysts. The cytotoxicity of the synthesized products against the heterogeneous human epithelial colorectal adenocarcinoma cell line (Caco‐2) was assessed by WST‐1 assay with concentration dependent cellular growth inhibitory effect especially for compounds 5l, 5h, and 5d. The dose response curves indicate that IC50 were 87 ± 3.11 μg/mL, 104 ± 4.78 μg/mL, and 108 ± 5.12 μg/mL, respectively.

“…To prepare the targeted dicarboxamide functionalized pyrazolo[1,5‐ a ]pyrimidines, we initially synthesized requisite intermediate 5‐amino‐ N ‐cyclohexyl‐3‐(methylthio)‐1 H ‐pyrazole‐4‐carboxamide ( 12 ) by the following literature method as shown in Scheme . Reaction of ethylcynoacetate (8 ) with cyclohexylamines ( 9 ) in refluxing toluene afforded 2‐cyano‐ N ‐cyclohexylacetamide ( 10) in 90% yield. This product underwent condensation reaction with carbon disulfide in the presence of base in DMF followed by S‐methylation to afford corresponding 2‐cyano‐3,3‐bis(methylthio)‐ N ‐phenylacrylamide ( 11 ).…”

Section: Resultsmentioning

confidence: 99%

A Concise [3 + 3] Heteroaromatization Synthetic Strategy Afford Dicarboxamide Functionalized Novel Pyrazolo[1,5‐a]Pyrimidines

Patel¹,

Kapuriya²,

Naliapara

2017

A concise and effective approach to dicarboxamide functionalized novel pyrazolo[1,5‐a]pyrimidine has been developed. The method involves [3 + 3] hetroaromatization of oxoketene dithioacetals (16a–x) with 5‐amino‐N‐cyclohexyl‐3‐(methylthio)‐1H‐pyrazole‐4‐carboxamide (12) in the presence of K2CO3. This method has advantages of excellent yields, operational simplicity, and avoidance of hazardous base like piperidine.