Microwave Assisted Synthesis of 1-Aryl-3-dimethylaminoprop-2-enones: A Simple and Rapid Access to 3(5)-Arylpyrazoles

Abstract

Condensation of aromatic acyl compounds with N,Ndimethylformamide diethyl acetal in a pressure tube under microwave heating gives 1-aryl-3-dimethylaminoprop-2-enones in almost quantitative yields. In the presence of hydrazine, these intermediates are transferred to the corresponding 3-arylpyrazoles.

Bis-enaminones as versatile precursors for terheterocycles:synthesis and reactions

“…11,18 When this reaction was repeated in a pressure tube for a few minutes in a microwave oven at 360W, it gave also the respective bis(enaminones) 17. In addition, a series of bis(enaminones) 23 was prepared as depicted below by initial reaction of 3-hydroxyacetophene 21 with the appropriate bis(halomethyl) linking unit followed by condensation of the resulting diacetyl derivative 22 with DMF-DMA.…”

Syntheses and characterisation of tris(3-(pyridin-2-yl)-1H-pyrazol-1-yl)methane and its bis(µ-hydroxo) dicobalt(II) complex

“…The substituted pyrazole 2-(1H-pyrazol-3-yl)pyridine was synthesised according to the published procedure. 15 Solvents and other chemicals were commercially available and were used without further purification. IR spectra were recorded on a Nicolet FT-IR spectrometer P510.…”

“…7,8 For the synthesis of the ligand tris(3-(pyridin-2-yl)-1H-pyrazol-1-yl)methane (HC(3-Pypz) 3 , 1) the substituted pyrazole 2-(1H-pyrazol-3-yl)pyridine 15 is used (Scheme 1a). With tetrabutylammoniumbromide as phase-transfer catalyst and sodium carbonate, we obtained the highest yields in this reaction.…”

“…2-(1H-Pyrazol-3-yl)pyridine 15 (13.0 g, 90 mmol) and tetra-n-butylammonium bromide (1.4 g, 4.3 mmol) were suspended in distilled water (219 ml). With vigorous stirring, sodium carbonate (60 g, 0.56 mol) was added gradually to the reaction mixture.…”

Synthesis of Novel Bis-enaminones by KHSO4-assisted Facile Michael Addition-elimination Reaction of 3-(dimethylamino)-1-phenylprop-2-en-1-ones with Diamines in Water

“…Keeping in view the synthetic potential of 3-(dimethylamino)-1-phenylprop-2-en-1-ones (formylated acetophenones) [2][3][4][5][6][7][8][9][10][11][12], we recently reported an efficient method for the formylation of active proton compounds [13]. We subsequently developed a facile synthetic strategy for the synthesis of enaminones by reacting formylated acetophenones with primary amines [14].…”