The Journal of Organic Chemistry
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1521, 1494, 1344, 1101, 727; H NMR (300 MHz, chloroform-d) δ
1720, 1458, 1176, 954, 802; H NMR (300 MHz, chloroform-d) δ
7.81 (d, J = 8.6 Hz, 2H), 7.46 (d, J = 8.6 Hz, 3H), 7.27 (dd, J = 8.5,
2.6 Hz, 1H), 7.09−6.99 (m, 2H). 13C{1H} NMR (76 MHz,
chloroform-d) δ 159.4 (d, J = 238.4 Hz), 156.6, 151.2, 134.75,
129.9 (d, J = 10.9 Hz), 129.1, 128.6, 126.2, 112.2 (d, J = 26.5 Hz),
111.8 (d, J = 9.7 Hz), 106.4 (d, J = 25.1 Hz), 101.9 (d, J = 4.1 Hz);
known compound.46
8.74 (t, J = 1.9 Hz, 1H), 8.28−8.17 (m, 2H), 7.65 (t, J = 8.0 Hz, 1H),
7.29−7.17 (m, 3H), 6.90 (dd, J = 6.8, 2.1 Hz, 1H), 4.10 (s, 3H).
13C{1H} NMR (76 MHz, CDCl3) δ 153.3, 148.8, 145.5, 144.5, 132.1,
130.5, 130.4, 129.8, 124.1, 122.9, 119.8, 113.7, 107.4, 103.9, 77.5,
77.0, 76.6, 56.1. Anal. Calcd (%) for C15H11NO4: C, 66.91; H, 4.12;
N, 5.20. Found: C, 66.08; H, 4.21; N, 5.40.
4.4.19. 5-Fluoro-2-(3-nitrophenyl) Benzofuran (3t). Yellow solid
(187 mg, 77% yield), mp 124−125 °C; FT-IR νmax (KBr): 1525,
1471, 1452, 1352, 1186, 1130, 792, 732; 1H NMR (300 MHz,
chloroform-d) δ 8.72 (t, J = 2.0 Hz, 1H), 8.24 (ddd, J = 8.2, 2.3, 1.0
Hz, 1H), 8.18 (dt, J = 7.9, 1.3 Hz, 1H), 7.67 (t, J = 8.0 Hz, 1H), 7.52
(dd, J = 9.0, 4.1 Hz, 1H), 7.35−7.30 (m, 1H), 7.19 (s, 1H), 7.11 (td, J
= 9.1, 2.6 Hz, 1H). 13C{1H} NMR (76 MHz, chloroform-d) δ 159.5
(d, J = 239.3 Hz), 154.9, 151.38, 148.8, 131.8, 130.4, 129.9, 129.5 (d,
J = 11.1 Hz), 123.2, 119.8, 113.2 (d, J = 26.5 Hz), 112.1 (d, J = 9.6
Hz), 106.8 (d, J = 25.1 Hz), 103.7 (d, J = 4.1 Hz); known compound
(CAS Registry Number: 1238315-03-1).
4.4.20. 2-(3-Nitrophenyl) Benzofuran (3u). Pale yellow solid (194
mg, 81% yield), mp 134−135 °C; FT-IR νmax (KBr): 3084, 1527,
1449, 1348, 800, 762; 1H NMR (300 MHz, DMSO-d6) δ 8.68 (t, J =
1.9 Hz, 1H), 8.39 (d, J = 7.9 Hz, 1H), 8.26 (dd, J = 8.2, 1.6 Hz, 1H),
7.83 (t, J = 8.0 Hz, 1H), 7.77 (s, 1H), 7.76−7.68 (m, 2H), 7.45−7.37
(m, 1H), 7.37−7.28 (m, 1H). 13C{1H} NMR (76 MHz, DMSO) δ
155.0, 153.2, 149.0, 131.8, 131.3, 131.3, 1289.0, 126.0, 124.1, 123.6,
122.2, 119.3, 111.9, 105.0; known compound.41
4.4.11. 7-Methoxy-2-(4-nitrophenyl) Benzofuran (3k). Yellow
solid (201 mg, 75% yield), mp 171−172 °C; FT-IR νmax (KBr):
2925, 1595, 1514, 1332, 1272, 852, 730; 1H NMR (300 MHz,
chloroform-d) δ 8.33 (d, J = 8.9 Hz, 2H), 8.05 (d, J = 8.9 Hz, 2H),
7.31−7.18 (m, 3H), 6.91 (dd, J = 6.8, 2.1 Hz, 1H), 4.10 (s, 3H).
13C{1H} NMR (76 MHz, CDCl3) δ 153.4, 147.3, 145.5, 144.9, 136.1,
130.3, 125.3, 124.3, 113.8, 107.7, 105.4, 77.5, 77.0, 76.6, 56.1; known
compound.44
4.4.12. N,N-Diethyl-2-(4-nitrophenyl) Benzofuran-6-amine (3l).
Red crystal (173 mg, 56% yield), mp 155−157 °C; FT-IR νmax (KBr):
1602, 1521, 1344, 1282, 1112, 862; 1H NMR (300 MHz, chloroform-
d) δ 8.29 (d, J = 9.0 Hz, 2H), 7.91 (d, J = 9.0 Hz, 2H), 7.45 (d, J = 8.7
Hz, 1H), 7.15 (s, 1H), 6.81 (s, 1H), 6.76 (dd, J = 8.7, 2.3 Hz, 1H),
3.48 (q, J = 7.0 Hz, 4H), 1.26 (t, J = 7.1 Hz, 6H). 13C{1H} NMR (76
MHz, CDCl3) δ 158.2, 150.6, 147.6, 146.1, 137.0, 124.4, 123.9, 121.9,
117.9, 110.3, 105.7, 93.4, 77.4, 77.0, 76.6, 45.0, 12.6; known
compound (PubChem ID: 16460625).
4.4.13. N,N-Diethyl-2-(3-nitrophenyl) Benzofuran-6-amine (3m).
Red crystal (161 mg, 52% yield), mp 98−99 °C; FT-IR νmax (KBr):
2966, 1631, 1625, 1525, 1506, 1357, 1344, 1118, 794, 734; 1H NMR
(300 MHz, chloroform-d) δ 8.63 (t, J = 2.0 Hz, 1H), 8.16−8.01 (m,
2H), 7.58 (t, J = 8.0 Hz, 1H), 7.44 (d, J = 8.7 Hz, 1H), 7.08 (s, 1H),
6.85 (s, 1H), 6.76 (d, J = 8.4 Hz, 1H), 3.47 (q, J = 7.1 Hz, 4H), 1.26
(t, J = 7.0 Hz, 6H). 13C{1H} NMR (76 MHz, CDCl3) δ 157.7, 148.8,
147.2, 132.8, 131.9, 129.6, 129.3, 121.6, 121.5, 120.9, 118.7, 110.2,
103.7, 93.8, 77.5, 77.0, 76.6, 45.0, 12.6. Anal. Calcd (%) for
C18H18N2O3: C, 69.66; H, 5.85; N, 9.03. Found: C, 68.94; H, 5.58; N,
9.20.
4.4.14. 5-Chloro-2-(naphthalen-1-yl) Benzofuran (3n). Pale
yellow solid (117 mg, 42% yield), mp 74−75 °C; FT-IR νmax
(KBr): 3053, 1689, 1444, 1261, 798, 773; 1H NMR (300 MHz,
chloroform-d) δ 8.53−8.42 (m, 1H), 8.04−7.86 (m, 3H), 7.75−7.52
(m, 5H), 7.34 (dd, J = 8.7, 2.2 Hz, 1H), 7.07 (s, 1H). 13C{1H} NMR
(76 MHz, CDCl3) δ 157.2, 153.4, 133.9, 130.6, 130.4, 129.9, 128.7,
128.5, 127.8, 127.5, 127.1, 126.2, 125.3, 125.3, 124.5, 120.5, 112.3,
105.4, 77.5, 77.0, 76.6; known compound (PubChem ID: 91689946).
4.4.15. 5-Bromo-2-(naphthalen-1-yl) Benzofuran (3o). Pale
yellow solid (145 mg, 45% yield), mp 72−73 °C; FT-IR νmax
(KBr): 3037, 1703, 1651, 1444, 1259, 1176, 790, 763; 1H NMR
(300 MHz, chloroform-d) δ 8.52−8.41 (m, 1H), 8.02−7.95 (m, 2H),
7.92 (dd, J = 7.2, 1.2 Hz, 1H), 7.83 (dd, J = 1.9, 0.7 Hz, 1H), 7.71−
7.56 (m, 3H), 7.56−7.42 (m, 2H), 7.07 (s, 1H). 13C{1H} NMR (76
MHz, CDCl3) δ 157.0, 153.7, 133.9, 131.0, 130.6, 129.9, 128.7, 127.7,
127.5, 127.2, 127.1, 126.2, 125.3, 125.3, 123.6, 116.0, 112.7, 105.3,
77.4, 77.0, 76.6; known compound (PubChem ID: 91689945).
4.4.16. 3-Methyl-2-(3-nitrophenyl) Benzofuran (3p). Yellow solid
(83 mg, 33% yield), mp 77−79 °C; FT-IR νmax (KBr): 2923, 1525,
1348, 808, 750, 734, 676; 1H NMR (300 MHz, chloroform-d) δ 8.72
(t, J = 2.0 Hz, 1H), 8.23 (ddd, J = 8.2, 2.3, 1.0 Hz, 1H), 8.18 (dt, J =
7.9, 1.4 Hz, 1H), 7.69 (t, J = 8.1 Hz, 1H), 7.65−7.53 (m, 2H), 7.45−
7.30 (m, 2H), 2.60 (s, 3H). 13C{1H} NMR (76 MHz, CDCl3) δ
153.9, 148.6, 148.0, 133.1, 131.9, 130.7, 129.7, 125.4, 122.8, 122.2,
121.2, 119.8, 113.8, 111.2, 9.6; known compound.42
4.4.21. 2-(4-Nitrophenyl) Benzofuran (3v). Yellow solid (167 mg,
70% yield), mp 182−184 °C; FT-IR νmax (KBr): 3085, 1600, 1517,
1
1344, 1110, 852, 752; H NMR (300 MHz, DMSO-d6) δ 8.43−8.33
(m, 2H), 8.26−8.16 (m, 2H), 7.85−7.66 (m, 3H), 7.44 (td, J = 8.4,
7.8, 1.4 Hz, 1H), 7.34 (td, J = 7.5, 0.9 Hz, 1H). 13C{1H} NMR (76
MHz, DMSO) δ 155.3, 153.4, 147.4, 136.1, 128.9, 126.5, 126.0,
124.9, 124.2, 122.4, 111.9, 106.6; known compound.37
4.4.22. 2-(4-Chlorophenyl) Benzofuran (3w). White solid (172
mg, 75% yield), mp 147−148 °C; FT-IR νmax (KBr): 3055, 1486,
1449, 1384, 1093, 804, 749, 585; 1H NMR (400 MHz, chloroform-d)
δ 7.85−7.79 (m, 2H), 7.63−7.59 (m, 1H), 7.57−7.52 (m, 1H), 7.47−
7.41 (m, 2H), 7.36−7.30 (m, 1H), 7.30−7.24 (m, 1H), 7.04 (d, J =
0.9 Hz, 1H). 13C{1H} NMR (101 MHz, CDCl3) δ 154.9, 154.8,
134.3, 129.1, 129.0, 126.1, 124.6, 123.1, 121.0, 111.2, 101.8; known
compound.38
4.4.23. 2-(3-Methoxyphenyl) Benzofuran (3x). White oil (143 mg,
64% yield), mp; FT-IR νmax (KBr): 2923, 1571, 1488, 1454, 1238,
1
779, 750; H NMR (300 MHz, chloroform-d) δ 7.67−7.57 (m, 2H),
7.53 (dt, J = 7.7, 1.3 Hz, 1H), 7.49 (dd, J = 2.6, 1.5 Hz, 1H), 7.45−
7.26 (m, 3H), 7.08 (s, 1H), 6.97 (ddd, J = 8.2, 2.6, 1.0 Hz, 1H), 3.95
(s, 3H). 13C{1H} NMR (76 MHz, CDCl3) δ 160.0, 155.8, 154.9,
131.8, 129.9, 129.2, 124.4, 123.0, 120.9, 117.6, 114.5, 111.2, 110.2,
101.7, 77.5, 77.1, 76.7, 55.4; known compound.43
4.4.24. 1-(3-Hydroxy-2-(3-nitrophenyl)-2,3-Dihydrobenzofuran-
2-yl) Ethane-1-one (Intermediate I5). 1H NMR (400 MHz,
chloroform-d) δ 8.56 (t, J = 2.1 Hz, 1H), 8.18 (ddd, J = 8.2, 2.3,
1.0 Hz, 1H), 8.05 (ddd, J = 7.9, 1.9, 1.1 Hz, 1H), 7.56 (t, J = 8.0 Hz,
1H), 7.41−7.35 (m, 2H), 7.20 (d, J = 8.1 Hz, 1H), 7.04 (td, J = 7.5,
1.0 Hz, 1H), 5.48 (s, 1H), 3.31 (d, J = 3.9 Hz, 1H), 2.44 (s, 3H).
13C{1H} NMR (101 MHz, CDCl3) δ 207.0, 158.6, 148.3, 139.6,
132.1, 131.6, 129.6, 126.3, 125.6, 123.6, 122.8, 121.1, 111.0, 81.4,
28.2.
ASSOCIATED CONTENT
4.4.17. 3-Methyl-2-(4-nitrophenyl) Benzofuran (3q). Yellow solid
(88 mg, 35% yield), mp 133−134 °C; FT-IR νmax (KBr): 1597, 1510,
1338, 1097, 854, 738; 1H NMR (300 MHz, chloroform-d) δ 8.38 (d, J
= 9.0 Hz, 2H), 8.03 (d, J = 9.0 Hz, 2H), 7.64 (d, J = 7.6 Hz, 1H), 7.56
(d, J = 8.1 Hz, 1H), 7.42 (td, J = 8.2, 7.7, 1.4 Hz, 1H), 7.34 (td, J =
7.5, 1.1 Hz, 1H), 2.61 (s, 3H). 13C{1H} NMR (76 MHz, CDCl3) δ
154.2, 148.2, 146.6, 137.5, 130.7, 126.6, 125.9, 124.1, 122.9, 119.9,
115.4, 111.3, 77.5, 77.0, 76.6, 9.9; known compound.42
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* Supporting Information
The Supporting Information is available free of charge at
NMR spectra for all reported compounds (PDF)
FAIR data, including the primary NMR FID files, for
compounds 3a−x as well as IR spectra (ZIP)
4.4.18. 2-(4-Chlorophenyl)-5-Fluorobenzofuran (3s). White solid
(182 mg, 74% yield), mp 123−124 °C; FT-IR νmax (KBr): 2925,
4760
J. Org. Chem. 2021, 86, 4756−4762