Acetals of lactams and acid amides. 61. Synthesis and transamination of indoxyls and pyrrol-2-in-4-ones

Design, synthesis and biological evaluation of indane-2-arylhydrazinylmethylene-1,3-diones and indol-2-aryldiazenylmethylene-3-ones as β-amyloid aggregation inhibitors

“…Indole enaminone 5b was prepared as described for 5a [33], which had yields and spectroscopic data in very good agreement with those reported; both were used without further purification.…”

“…The reaction of 3-acetoxyindoles with DMFDMA yielded the (2Z)-2-(dimethylaminomethylene)-indol-3-ones 5a-b [33]. The Z configuration was assigned to intermediates 5a-b on the basis of 1 H NMR spectral data.…”

Design and Synthesis of Pyrano[3,2-b]indolones Showing Antimycobacterial Activity

“…Mild oxidation of the formyl group of N -protected indoles 3 was successfully carried out using meta -chloro­peroxy­benzoic acid ( m CPBA) in a dichloro­methane medium . 5-Substituted 1-acetyl-1 H -indole-3-yl esters of formic acid 4 thus obtained were reacted with di­methoxy­methyl­piperidine to introduce the piperidin-1-ylmethylene fragment at the 2-position of indole and then with triethylamine in methanol to synthesize the corresponding compounds, 5 . In the next stage, the acetylation of indoles 5 at the 3-position with acetyl chloride led to acetates 6 .…”

“…Synthesis of Methyl 2-Cyano-3-(3-hydroxy-1H-indol-2-yl)-3-(methylthio)acrylate (15). To a suspension of NaH (0.01 mol) in methanol were added 1-acetylindolin-3-one 13 (0.01 mol) and methyl 2-cyano-3,3-bis(methylthio)acrylate 14 (0.01 mol) dropwise at room temperature, and then the resulting mixture was refluxed for 2 h. The mixture was concentrated in vacuo and treated with water and 1 to 2 drops of 10% HCl solution.…”

Methylene Meldrum’s Acid Derivatives of Indoxyl and Their Cyclization Reactions under Flash Vacuum Pyrolysis Conditions

“…The 2-methylene Meldrum's derivative of indoxyl 2 is known, 1 but the precursor (dimethylamino)methylene compound 11 was obtained directly from indoxyl (3) rather than from its N-acetyl derivative 15 and gave 2 in 40% overall yield (Scheme 3). FVP of 2 at 650 °C proceeded in analogous fashion to the corresponding pyrrolone 2 and provided pyrano[3,2-b]indol-2(5H)-one (12) in 42% yield by cyclisation of the intermediate ketene onto the carbonyl group (Scheme 3), rather than the isomeric 9-hydroxypyrrolo[1,2-a]indol-3-one which would have been obtained by cyclisation onto the nitrogen atom.…”