Furans and their Benzo Derivatives: Structure

One-Pot Synthesis of 2-(Het)aryl/alkyl-3-cyanobenzofurans from 2-(2-Bromoaryl)-3-(het)aryl-3-(methylthio)acrylonitriles and Benzyl Carbamate

“…Purification of compounds was performed by column chromatography using 60−120 mesh silica gel. Nuclear magnetic resonance spectra were recorded on a 400 MHz FT-NMR spectrometer with CDCl 3 (or) DMSO-d 6 as solvent with residual solvent protons as internal standard (δ 7.26 for CDCl 3 and δ 2.50 for DMSO-d 6 in 1 H NMR and δ 77.16 for CDCl 3 and δ 39.52 for DMSO-d 6 in 13 C NMR). Chemical shifts were reported in δ ppm, and the coupling constants were reported as J values in Hertz (Hz).…”

“…(E/Z)-2-(2-Bromo-5-methoxyphenyl)-3-(4-fluorophenyl)-3-(methylthio)acrylonitrile (1b). Yellow solid (279 mg, 74%); mp 103−105 °C; R f 0.3 (1:9 EtOAc/hexane); 1 H NMR (400 MHz, CDCl 3 ) δ 7.35 (d, J = 8.8 Hz, 1H), 7.19−7.15 (m, 2H), 6.96−6.92 (m, 2H), 6.63 (dd, J = 8.8 Hz, 3.2 Hz, 1H), 6.48 (d, J = 3.2 Hz, 1H), 3.61 (s, 3H), 2.10 (s, 3H); 13 C{ 1 H} NMR (100 MHz, CDCl 3 ) δ 163.2 ( 1 J C−F = 250 Hz), 160.4, 158.9, 135.7, 133.8, 131.3, 131.2, 130.2, 130.4, 117.8, 116.7, 116.5, 116.1, 115.9, 114.7, 109.2, 55.6, 16.5 151.7, 151.0, 133.8, 133.7, 133.0, 132.9, 132.4, 131.5, 131.0, 130.5, 124.7, 124.6, 121.5, 120.7, 120.4, 120.3, 120.1, 118.2, 117.7, 115.2, 115.2, 115.0, 111.7, 111.2, 104.9, 104.1, 40.1, 40.0, 16.8, 16.7 3, 150.1, 150.0, 149.8, 149.2, 148.7, 135.8, 133.8, 128.3, 127.8, 121.8, 121.2, 119.8, 115.9, 115.8, 115.6, 115.2, 114.4, 114.3, 103.2, 102.8, 101.2, 56.4, 56.3, 42.3, 42.0, 19.5, 18.4;IR (neat, cm −1 ) 2936IR (neat, cm −1 ) , 2217IR (neat, cm −1 ) , 1545IR (neat, cm −1 ) , 1486IR (neat, cm −1 ) , 1275 3, 160.6, 133.6, 133.5, 132.2, 131.0, 130.6, 128.7, 128.6, 128.3, 128.1, 128.0, 127.81, 127.8, 127.6, 127.55, 127.5, 127.3, 126.3, 125.1, 117.2, 114.5, 117.2, 114.5, 109.0, 55.2, 16.6;IR (neat, cm −1 ) 2831IR (neat, cm −1 ) , 2221IR (neat, cm −1 ) , 1550IR (neat, cm −1 ) , 1425IR (neat, cm −1 ) , 1236 (m, 1.16H), 6.98 (d, J = 8.8 Hz, 0.42H), 6.82 (s, 0.42H), 6.53−6.51 (m, 1H), 6.26 (t, J = 3.6 Hz, 0.58H), 6.11−6.10 (m, 0.42H), 5.95 (t, J = 3.6 Hz, 0.42H), 3.82 (s, 1.74H), 3.46 (s, 1.26H), 2.11 (s, 1.26H), 1.87 (s, 1.74H); 13 C{ 1 H} NMR (100 MHz, CDCl 3 ) δ 154. 5, 152.8, 134.4, 133.7, 133.5, 132.5, 132.2, 128.6, 128.3, 128.1, 128.0, 127.8, 127.8, 127.6, 127.5, 127.4, 127.3, 126.4, 125.9, 125.8, 125.3, 124.7, 117.4, 117.0, 114.9, 113.5, 109.9, 109.6, 109.0, 108.9, 34.7, 16.2, 15.8;IR (neat, cm −1 ) 2982IR (neat, cm −1 ) , 2211IR (neat, cm −1 ) , 1546IR (neat, cm −1 ) , 1472IR (neat, cm −1 ) , 1274 8, 160.9, 149.7, 143.6, 140.9, 133.3, 130.9, 125.8, 122.7, 116.6, 114.4, 105.4, 55.4, 16.6…”

“…5, 152.8, 134.4, 133.7, 133.5, 132.5, 132.2, 128.6, 128.3, 128.1, 128.0, 127.8, 127.8, 127.6, 127.5, 127.4, 127.3, 126.4, 125.9, 125.8, 125.3, 124.7, 117.4, 117.0, 114.9, 113.5, 109.9, 109.6, 109.0, 108.9, 34.7, 16.2, 15.8;IR (neat, cm −1 ) 2982IR (neat, cm −1 ) , 2211IR (neat, cm −1 ) , 1546IR (neat, cm −1 ) , 1472IR (neat, cm −1 ) , 1274 8, 160.9, 149.7, 143.6, 140.9, 133.3, 130.9, 125.8, 122.7, 116.6, 114.4, 105.4, 55.4, 16.6 1q). Off-white solid (243 mg, 73%, E/Z = 63:37); mp 163−165 °C; R f 0.3 (6:4 EtOAc/ hexane); 1 H NMR (400 MHz, CDCl 3 ) δ 8.42 (dd, J = 4.8 Hz, 2.0 Hz, 0.63H), 8.23 (dd, J = 4.8 Hz, 2.0 Hz, 0.37H), 7.74 (dd, J = 8.0 Hz, 2.0 Hz, 0.63H), 77.39 (dd, J = 8.0 Hz, 4.8 Hz, 0.63H), 7.29−7.26 (m, 0.37H), 7.13 (dd, J = 8.0 Hz, 4.8 Hz, 0.37H), 6.84 (t, J = 2.0 Hz, 0.63H), 6.62 (t, J = 2.0 Hz, 0.37H), 6.50 (dd, J = 3.6 Hz, 1.6 Hz, 0.63H), 6.24 (dd, J = 4.0 Hz, 2.8 Hz, 0.63H), 6.05−5.99 (m, 0.63H), 3.79 (s, 1.89H), 3.52 (s, 1.11H), 2.11 (s, 1.11H), 1.93 (s, 1.89H); 13 C{ 1 H} NMR (100 MHz, CDCl 3 ) δ 156. 3, 155.0, 150.4, 149.5, 143.2, 142.7, 140.5, 140.3, 133.0, 132.0, 126.8, 126.6, 125.5, 124.5, 123.1, 122.7, 117.1, 116.5, 115.1, 114.1, 109.2, 109.1, 105.9, 105.8, 34.8, 34.7, 16.1, 16.0 Procedure for the Synthesis of 2-(2-Bromo-5-methoxyphenyl)-3-(4-methoxyphenyl)-3-oxopropanenitrile (8a).…”

“…The solvent was removed under reduced pressure to give the crude product, which was purified by column chromatography over silica gel using EtOAc/hexane as eluents. Off-white solid (350 mg, 84%); mp 116−118 °C; R f 0.3 (2:8 EtOAc/hexane); 1 H NMR (400 MHz, CDCl 3 ) δ 7.97 (d,J = 8.8 Hz,2H),7.49 (d,J = 8.8 Hz,1H),7.06 (d,J = 3.2 Hz,1H),6.95 (d,J = 8.8 Hz,2H), 6.80 (dd, J = 9.0 Hz, 3.2 Hz, 1H), 6.03 (s, 2H), 3.88 (s, 3H), 3.78 (s, 3H); 13 C{ 1 H} NMR (100 MHz, CDCl 3 ) δ 186. 7, 164.9, 159.8, 134.1, 131.9, 131.7, 126.7, 117.1, 116.0, 115.7, 114.5, 113.9, 55.8, 45.8 Procedure for Copper-Catalyzed Cyclization of 2-(2-Bromo-5-methoxyphenyl)-3-(4-methoxyphenyl)-3-oxopropanenitrile (8a) to 5-Methoxy-2-(4-methoxyphenyl)benzofuran-3-carbonitrile (7a).…”

“…Substituted benzofuran derivatives have drawn considerable attention for their wide distribution in naturally occurring and designed molecules, , displaying a diverse range of useful biological activities . Examples include amiodarone, a clinically used drug for controlling intractable cardiac arrhythmias and daphnodorin A and B displaying α-glucosidase inhibitory, antifungal, insecticidal, and antitumor activities .…”