Synthesis of quinolines via acid-catalyzed cyclodehydration of 2-(tosylamino)chalcones

Oxidative Rearrangement of 2‐(2‐Aminobenzyl)furans: Synthesis of Functionalized Indoles and Carbazoles

“…Oppositely, the use of TfOH in DCE led to the partial cyclisation of the starting chalcone 14 a affording 2-substituted quinoline via Friedländerlike reaction. [17] Using the optimized reaction conditions, we synthesized a series of substituted 2-(2-aminobenzyl)furans 16 a-h in high yields and studied their oxidative rearrangement (Table 2). We found that the desired indoles 17 a-h were formed in high [d] DCE TsOH 2089 [e] 12 [d] CH 3 CN TMSCl 2095 [e] [a] All reactions performed at 0.1 mmol scale.…”

“…In both cases, the reaction can be efficiently scaled up; the yield of 16 a being slightly dropped to 89 % using TsOH in DCE (Table 1, entry 11), while TMSCl provided the target product in 95 % yield (Table 1, entry 12). Oppositely, the use of TfOH in DCE led to the partial cyclisation of the starting chalcone 14 a affording 2‐substituted quinoline via Friedländer‐like reaction [17] …”

“…Synthesis of 2‐tosylaminochalcones 14 a–h . The 2‐tosylaminochalcones 14 were synthesized according to the reported procedures [17] …”

“…The 2-tosylaminochalcones 14 were synthesized according to the reported procedures. [17] (E)- N-{2-[3-(2,3-Dihydrobenzo[b][1,4] 1,148.3,143.9,143.6,138.4,136.3,135.5,131.6,131.1,131.0,129.8 (2 C),127.7,127.4 (2 C),127.3,127.1,124.4,122.9,118.2,117.5,64.9,64.3,21.4 ppm;IR (nujol) 3167,1647,1610,1578,1510,1329,1290,1167 General Procedure for the Synthesis of 2-(2-Aminobenzyl)furans 16. To a solution of corresponding 2-tosylaminochalcone 14 (1 mmol) and 2-methylfuran 15 (265 μL, 3 mmol) in CH 3 CN (4 mL) was added TMSCl (25 μL, 0.2 mmol).…”

Advances in the Synthesis of Heteroaromatic Hybrid Chalcones

“…The utility of chalcones both as a pharmacophore and as a scaffold in the synthesis of a wide variety of heterocycles ranging from pyrazoles, isoxazoles, triazoles, barbituric acid derivatives, etc. has been investigated thoroughly over the years, with numerous research articles as well as several reviews appearing in the last decade describing the current chalcone synthetic strategies, the heterocycles derived from them, and the bioactivity and pharmaceutical uses of these compounds [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. Within that context, the preparation of more highly functionalized chalcones that contain heteroaromatic components has been an area of intense research over the last decade [ 10 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ].…”