Microwave‐Assisted, Solvent‐Free, Three‐Component Domino Protocol: Efficient Synthesis of Polysubstituted‐2‐Pyridone Derivatives

Abstract

Microwave assisted highly efficient synthesis of polysubstituted‐2‐pyridone derivatives via a three‐component domino reaction of 1,3‐dicarbonyl compounds, diethyl ethoxymethylenemalonate and amines is established. The main advantages of this protocol are short reaction time, good functional group compatibility, high bond‐forming efficiency, being solvent‐ free, availability of starting materials and simple experimental procedure. Furthermore, a postulated reaction pathway included imine‐enamine tautomerism/ condensation/ aza‐ene reaction/ intramolecular cyclization processes for this three‐component domino protocol is also discussed.

Construction of Fully Substituted 2-Pyridone Derivatives via Four-Component Branched Domino Reaction Utilizing Microwave Irradiation

“…Recently, our group has developed a series of new MCRs that offer convenient and efficient access to some heterocycles of chemical and pharmaceutical under sustainable conditions. − In continuation of our research, we disclose herein for the first time a novel one-pot four-component synthesis of a series of novel fully substituted 2-pyridone derivatives via self-sorting branched domino reaction between two categories of dicarbonyl compounds, triethyl orthoformate as C 1 building block, and amines under microwave irradiation and catalyst- and solvent-free conditions. In the process of reaction with cascade CN bond formation, CN bond changes to CN bond/CC bond formation, CC bond formation and CN bond formation (Scheme ).…”

N-tartalmú heterociklusok szintézise 1,3-dikarbonil részegységet tartalmazó Mannich szubsztrátok diverzitás-orientált transzformációival

“…[151] Katalizátor-és oldószermentes körülmények mellett, a 321 dikarbonil szubsztrát, dietil-(etoxi-metilén)malonáttal (322) és a 323 primer aminokkal egy multikomponensű dominó reakción keresztül, mikrohullámú besugárzás mellett adja a 324 1,3,5,6-tetraszubsztituált PY-2-on analógokat (II., 42. ábra). [152] 42. ábra. Szubsztituált PY-2-on származékok szintézise kondenzációs (I.)…”

“…Hz, 1H; CH), 3,79 (q, J = 7,1 Hz, 2H; CH2), 2,24 (s, 6H; 2 CH3), 0,82 (t, J = 7,1 Hz, 3H; CH3) ppm; 1 202,21 (s;Cq),201,81 (s;Cq),161,68 (s;Cq),146,28 (s;Cq),128,88 (s;128,30 (q,J = 31,5 Hz;Cq),125,63 (q,J = 3,5 Hz;127,94 (m;Cq) 13 C NMR (126 MHz,68,160,52,152,74,149,85,137,32,135,41,130,89 (q,J = 32,6,30,6 Hz),130,83,124,50 (q,J = 3,6 Hz),124,19 (q,…”

“…Etil-7-metil-2-(piridin-2-il)-imidazo[1,2-a]pirimidin-3-karboxilát (460) 1 H NMR (500 MHz, kloroform-d) δ = 9,47 (d,J = 7,1 Hz,1H),8,73 (d,J = 4,4 Hz,1H),7,85 (d,J = 7,8 Hz,1H),7,81 (td,J = 7,5,1,4 Hz,1H),7,35 (t,J = 5,4 Hz,1H),6,99 (d,J = 7,1 Hz,1H), 4,28 (q, J = 7,1 Hz, 2H), 2,71 (s, 3H), 1,17 (t, J = 7,1 Hz, 3H) ppm; 13 C NMR (126 MHz,40,160,70,153,04,152,67,149,55,148,82,136,00,135,07,125,08,123,46,…”

“…Etil-2-(3-brómfenil)-6-klór-imidazo[1,2-a]pirimidin-3-karboxilát (468) 1 H NMR (500 MHz, kloroform-d) δ = 9,78 (d,J = 2,5 Hz,1H),8,69 (d,J = 2,7 Hz,1H),8,02 (s,1H),7,81 (d,J = 7,8 Hz,1H),7,59 (d,J = 8,2 Hz,1H),7,34 (t,J = 7,9 Hz,1H), 4,38 (q, J = 7,1 Hz, 2H), 1,33 (t, J = 7,2 Hz, 3H) ppm; 13 C NMR (126 MHz,38,153,47,152,08,147,86,135,04,133,71,133,46,132,38,129,36,129,05,121,56,120,09,…”