An efficient synthesis of novel functionalized benzo[h]pyrano[2,3-b]quinolines and pyrano[2,3-b]quinoline derivatives via one-pot multicomponent reactions

Ultrasound-promoted synthesis of novel N-arylamino-3,5′-biquinoline derivatives: their applications in live-cell imaging and in vitro anticancer activity evaluation

“…31 Our interest in ultrasoundassisted reactions and our previous work developing the multicomponent syntheses of functionalized heterocyclic compounds 30 led us to design a method for the synthesis of N-arylamino-3,5 0biquinolines via multicomponent domino reactions of a,adicyanoolefines, and 2-chloro-3-formylquinoline derivatives in EtOH catalyzed by Et 3 N under ultrasonic irradiation with good to excellent yields, and a process that is potentially conducive to natural product synthesis. In the present study, using a domino reaction, the dicyanoquinoline ring was obtained by simultaneously constructing two new rings, including benzene and pyridine, resulting from Knoevenagel condensation/Michael addition/intramolecular cyclization (converting two cyano groups into two amine groups), [1,5]-H or [1,3]-H shift and aromatization tandem reactions in air. Therefore, in order to conduct a one-pot sequential process, a mixture of 2-chloro-3formylquinoline derivatives 1a (1 mmol), a,a-dicyanoolefines 2a (2 mmol) and Et 3 N (15 mmol%) were stirred in EtOH under ultrasonic (US) irradiation with an amplitude of 60%.…”

“…Initially, Et 3 N deprotonates (1-arylethylidene)malononitrile 2 to give anion 4. Anion 4 then undergoes Knoevenagel condensation with compound 1 to generate intermediate 5 by Michael addition (5 to 6), intramolecular cyclization (6 to 7), [1,5]-H shift (7 to 8), and a second intramolecular cyclization (formation 9). Finally, air oxidation and tautomerization result in the formation of product 3.…”

“…Derivatives 3a, 3g, 3h, 3i, and 3j were purified by washing with EtOH twice and the other derivatives 3b, 3c, 3d, 3e, and 3f were purified by recrystallization in DMF. (17), 472 (37), 469 (6), 446 (6), 427 (5), 393 (5), 235 (32), 213 (9), 194 (9), 76 (9), 51 (14) 19) Å 3 , Z = 8, Dc = 1.368 mg m À3 , F (000) = 2096, crystal dimension 0.20 Â 0.15 Â 0.10 mm, radiation, Mo Ka (l = 0.71073 Å), 1.9 r 2y r 25.0, intensity data were collected at 290 K with a Bruker APEX area-detector diffractometer employing a o/2y scanning technique in the range of À32 r h r 32, À9 r k r 9, À26 r l r 24; the structure was solved by direct methods, all non-hydrogen atoms were positioned and anisotropic thermal parameters refined from 4153 observed reflections with R (into) = 0.0499 by a full-matrix least-squares technique converged to R 1 = 0.0668, and wR 2 = 0.1571 [I 4 2sigma(I)].…”

“…IR (KBr) (n max , cm À1 ): 3440, 3336, 3225, 2220, 1642, 1566, 1490, 1420, 1073, 1004, 837, 824, 803 cm À1 . 1 H NMR (300.13 MHz, DMSO-d 6 ): 2.51 (3H, s, CH 3 ), 6.85 (1H, dd, 3 13 +4 , 19), 682 (M +3 , 21), 681 (M +2 , 88), 680 (M +1 , 80), 679 (M + , 100), 677 (25), 676 (50), 645 (18), 644 (33), 600 (4), 563 (14), 522 (6), 482 (5), 281 (5), 260 (13), 228 (17), 207 (6), 148 (51), 83 (15), 56 (61), 55 (51), 50 (8) 2 0 -Amino-4 0 ,7 0 -bis(4-bromophenyl)-2-chloro-6-methoxy-[3,5 0biquinoline]-3 0 ,8 0 -dicarbonitrile (3d). Light yellow solid, m.p.…”

“…The 1-aza-naphthalene or quinoline core is found in many dyes, insecticides, drugs, and natural compounds such as alkaloids. 4,5 For this reason, chemists and pharmacists are seeking to develop new ways to synthesize these molecules. For instance, drugs such as brequinar, bedaquiline, piperaquine, mefloquine, primaquine and chloroquine are all quinoline-based (Fig.…”