Iron/acetic acid mediated intermolecular tandem C–C and C–N bond formation: an easy access to acridinone and quinoline derivatives

Abstract

An efficient iron/acetic acid mediated one pot reductive cyclization protocol was successfully developed for the synthesis of acridinone and quinoline derivatives.

NH4OAc‐Promoted Cascade Approach towards Aberrant Synthesis of Chromene‐Fused Quinolinones

“…Sashidhara group reported iodine‐catalyzed tandem process for annulation between 4‐hydroxycoumarin, aromatic aldehydes, and aromatic amines under MW irradiation, affording 6 H ‐chromeno[4,3‐ b ]quinolin‐6‐ones in high yields (Scheme b) . Yao and co‐workers synthesized 6 H ‐chromeno[4,3‐ b ]quinolin‐6‐ones through reductive cyclization between 4‐hydroxycoumarin and ortho ‐nitrobenzaldehydes using excess of Fe and acetic acid (Scheme c) . With the advent of elegant Csp 2 ‐H formylation protocols, Su and co‐workers reported a Cu‐catalyzed cyclization protocol from 4‐(phenylamino)‐2 H ‐chromen‐2‐ones, employing DMF as formyl‐generating source and TBPB as oxidant, affording functionalized 6 H ‐chromeno[4,3‐ b ]quinolin‐6‐ones in moderate‐to‐good yields (Scheme d) .…”

Effective and Sustainable Access to Quinolines and Acridines: A Heterogeneous Imidazolium Salt Mediates C–C and C–N Bond Formation

“…: 160–162 °C (AcOEt) (Lit. : 160–162 °C): IR (ATR): ν̃ = 2956, 2888, 1682, 1587, 1484, 1399, 1371, 1207, 1169, 1135, 1073, 1061, 1003, 935, 913, 841, 677 cm –1 ; 1 H NMR (400 MHz, CDCl 3 ): δ H = 8.76 (s, 1H, CH Ar ), 8.02 (d, J = 9.0 Hz, 1H, CH Ar ), 7.90 (d, J = 2.3 Hz, 1H, CH Ar ), 7.74 (dd, J = 9.0 and 2.3 Hz, 1H, CH Ar ), 3.37–3.28 (m, 2H, COCH 2 ), 2.85–2.77 (m, 2H, CCH 2 ), 2.34–2.23 (m, 2H, COCH 2 C H 2 ) ppm; 13 C NMR (101 MHz, CDCl 3 ): δ C = 197.5, 162.3, 147.8, 136.4, 133.4, 132.7, 130.1, 128.1, 127.5, 127.0, 39.1, 33.3, 21.7 ppm; MS (EI): m/z 233 (M + + 2, 31 %), 232 (27), 231 (M + , 96), 230 (23), 207 (11), 205 (32), 204 (20), 203 (100), 202 (23), 175 (22), 167 (19), 140 (44), 84 (12).…”

“…6,7,8,9‐Tetrahydro‐1,3‐Dioxolo[4,5‐ b ]acridin‐9‐one (3fe): White solid; purification by column chromatography (hexane/ethyl acetate, 4.0:6.0), 93 % yield; m.p. : 213–214 °C (AcOEt) (Lit.…”

“…: 213–214 °C (AcOEt) (Lit. : 210–212 °C); IR (ATR): ν̃ = 3029, 2959, 2906, 2892, 2788, 1666, 1588, 1469, 1460, 1446, 1398, 1357, 1243, 1211, 1180, 1135, 1036, 1004, 946, 938, 907, 898, 849, 837, 785, 778, 687 cm –1 ; 1 H NMR (400 MHz, CDCl 3 ): δ H = 8.59 (s, 1H, CH Ar ), 7.33 (s, 1H, CH Ar ), 7.10 (s, 1H, CH Ar ), 6.14 (s, 2H, 2 × CH Ar ), 3.31–3.14 (m, 2H, COCH 2 ), 2.82–2.67 (m, 2H, CCH 2 ), 2.35–2.09 (m, 2H, CH 2 C H 2 CH 2 ) ppm; 13 C NMR (101 MHz, CDCl 3 ): δ C = 198.0, 160.2, 153.4, 148.6, 148.2, 135.4, 124.8, 123.9, 104.9, 104.0, 102.3, 39.0, 32.8, 22.0 ppm; MS (EI): m/z 242 (13 %), 241 (M + , 100), 240 (31), 214 (15), 213 (69), 212 (15), 207 (25), 185 (30), 128 (11), 127 (19), 100 (11), 77 (11).…”

Syntheses of 4-Indolylquinoline Derivatives via Reductive Cyclization of Indolylnitrochalcone Derivatives by Fe/HCl

“…For the past decade, we have been working on the use of reductive cyclization reactions [25,26,27,28,29,30,31,32] to generate a wide variety of nitrogen heterocycles, including indolylquinoline derivatives, 3,3′-biindoles, quinoline derivatives, 2 H -1,4-benzoxazin-3-(4 H )-ones, carbazolone derivatives, 2,3-disubstituted indole derivatives, acridinones and phenathridine derivatives by using Fe/AcOH as a reagent [33,34,35,36]. In continuation to our interest on reductive cyclization reactions, we proposed to synthesize 4-indolylquinoline derivatives in two steps starting from 2-nitrochalcone derivatives and indoles.…”