M. Ghosh, A. Hajra
FULL PAPER
3-(4-Bromophenyl)-2,5-dimethylfuro[3,2-c]quinolin-4-(5H)-one (3ai):
147.4, 132.7, 130.4, 124.9, 124.4, 124.1, 123.6, 120.7, 117.2, 116.8,
110.6, 108.3, 101.3, 12.7 ppm. C19H12O5 (320.30): calcd. C 71.25,
White solid (138 mg, 75%). M.p. 153–155 °C. IR (KBr): ν = 3042,
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1
1659, 1103, 524 cm–1. H NMR (400 MHz, CDCl3): δ = 7.99 (d, J H 3.78; found C 71.10, H 3.98.
= 8.0 Hz, 1 H), 7.55–7.48 (m, 3 H), 7.44–7.40 (m, 3 H), 7.32–7.29
2-Methyl-3-(naphthalen-1-yl)-4H-furo[3,2-c]chromen-4-one (4ae):
(m, 1 H), 3.72 (s, 3 H), 2.50 (s, 3 H) ppm. 13C NMR (100 MHz,
CDCl3): δ = 159.2, 154.0, 151.0, 137.8, 133.3, 131.7, 129.7, 129.3,
128.1, 122.2, 120.9, 119.6, 114.9, 113.8, 112.8, 29.2, 12.6 ppm.
C19H14BrNO2 (368.23): calcd. C 61.97, H 3.83, N 3.80; found C
62.09, H 3.69, N 3.70.
Gummy mass (123 mg, 76%). IR (KBr): ν = 3042, 1736, 1069 cm–1.
˜
1H NMR (400 MHz, CDCl3): δ = 7.96 (t, J = 8.8 Hz, 3 H), 7.71
(d, J = 8.4 Hz, 1 H), 7.60–7.56 (m, 1 H), 7.54–7.50 (m, 3 H), 7.48–
7.45 (m, 2 H), 7.41–7.38 (m, 1 H), 2.37 (s, 3 H) ppm. 13C NMR
(100 MHz, CDCl3): δ = 157.5, 156.4, 153.0, 152.6, 133.8, 132.4,
130.4, 128.9, 128.6, 127.8, 126.4, 126.0, 125.6, 125.4, 124.4, 120.7,
118.4, 117.3, 113.1, 111.5, 12.6 ppm. C22H14O3 (326.35): calcd. C
2-Ethyl-3-(4-methoxyphenyl)-5-methylfuro[3,2-c]quinolin-4(5H)-one
(3af): Colourless liquid (129 mg, 78%). IR (KBr): ν = 3060, 1653,
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1
1109 cm–1. H NMR (400 MHz, CDCl3): δ = 7.93 (d, J = 8.0 Hz, 80.97, H 4.32; found C 80.82, H 4.15.
1 H), 7.44–7.40 (m, 1 H), 7.37–7.31 (m, 3 H), 7.22–7.18 (m, 1 H),
2-Ethyl-3-(4-methoxyphenyl)-4H-furo[3,2-c]chromen-4-one (4af):
6.90 (d, J = 8.4 Hz, 2 H), 3.77 (s, 3 H), 3.63 (s, 3 H), 2.75 (q, J =
7.6 Hz, 2 H), 1.26 (t, J = 7.6 Hz, 3 H) ppm. 13C NMR (100 MHz,
CDCl3): δ = 159.5, 159.0, 155.6, 153.8, 137.9, 131.5, 129.0, 123.6,
122.1, 121.0, 119.5, 114.9, 114.2, 113.5, 113.1, 55.3, 29.2, 20.0,
13.3 ppm. C21H19NO3 (333.39): calcd. C 75.66, H 5.74, N 4.20;
found C 75.52, H 5.92, N 4.05.
Yellow liquid (120 mg, 75%). IR (KBr): ν = 3059, 1689, 1075 cm–1.
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1H NMR (400 MHz, CDCl3): δ = 7.89 (d, J = 8.4 Hz, 1 H), 7.49–
7.42 (m, 4 H), 7.36–7.32 (m, 1 H), 7.01 (d, J = 8.8 Hz, 2 H), 3.87
(s, 3 H), 2.86 (q, J = 7.6 Hz, 2 H), 1.37 (t, J = 7.6 Hz, 3 H) ppm.
13C NMR (100 MHz, CDCl3): δ = 159.3, 158.0, 156.3, 156.2, 152.3,
131.1, 130.2, 124.3, 122.3, 120.6, 119.5, 117.1, 113.8, 112.9, 109.7,
55.3, 20.0, 13.1 ppm. C20H16O4 (320.34): calcd. C 74.99, H 5.03;
found C 75.12, H 4.89.
5-Methyl-7,8,9,10,11,12-hexahydrocycloocta[4,5]furo[3,2-c]quinolin-
6(5H)-one (3aj): Pale yellow oil (119 mg, 85%). IR (KBr): ν = 3068,
˜
1655, 1101 cm–1. 1H NMR (400 MHz, CDCl3): δ = 7.79 (d, J =
8.8 Hz, 1 H), 7.36–7.31 (m, 1 H), 7.24 (d, J = 8.4 Hz, 1 H), 7.13
(t, J = 7.6 Hz, 1 H), 3.61 (s, 3 H), 2.95 (t, J = 6.4 Hz, 2 H), 2.81
(t, J = 6.4 Hz, 2 H), 1.72–1.68 (m, 4 H), 1.44–1.36 (m, 4 H) ppm.
13C NMR (100 MHz, CDCl3): δ = 160.2, 154.3, 153.0, 137.5, 128.4,
121.9, 120.6, 118.2, 115.0, 114.7, 113.3, 28.9, 28.5, 27.9, 26.0, 25.9,
25.5, 21.4 ppm. C18H19NO2 (281.35): calcd. C 76.84, H 6.81, N
4.98; found C 76.72, H 6.72, N 4.80.
2,6-Dimethyl-3-phenyl-4H-furo[3,2-c]pyran-4-one (5aa): Gummy
mass (81 mg, 68%). IR (KBr): ν = 3068, 1721, 1070 cm–1. 1H NMR
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(400 MHz, CDCl3): δ = 7.42–7.39 (m, 2 H), 7.38–7.34 (m, 2 H),
7.29–7.26 (m, 1 H), 6.31 (s, 1 H), 2.36 (s, 3 H), 2.27 (s, 3 H) ppm.
13C NMR (100 MHz, CDCl3): δ = 160.9, 159.5, 159.4, 150.1, 130.4,
129.9, 128.9, 128.3, 127.7, 119.2, 95.6, 20.3, 12.6 ppm. C15H12O3
(240.26): calcd. C 74.99, H 5.03; found C 75.12, H 4.89.
2,6-Dimethyl-3-(p-tolyl)-4H-furo[3,2-c]pyran-4-one (5ab): Yellow
2-Methyl-3-phenyl-4H-furo[3,2-c]chromen-4-one (4aa): White solid
gummy mass (81 mg, 64%). IR (KBr): ν = 3058, 1720, 1085 cm–1.
˜
(110 mg, 80 %). M.p. 145–147 °C. IR (KBr): ν = 3064, 1731,
˜
1H NMR (400 MHz, CDCl3): δ = 7.29 (d, J = 8.0 Hz, 2 H), 7.17
(d, J = 8.0 Hz, 2 H), 6.30 (s, 1 H), 2.35 (s, 3 H), 2.31 (s, 3 H), 2.26
(s, 3 H) ppm. 13C NMR (100 MHz, CDCl3): δ = 160.8, 159.6,
159.2, 149.8, 137.4, 129.7, 129.0, 127.3, 119.1, 107.6, 95.6, 21.4,
20.2, 12.5 ppm. C16H14O3 (254.28): calcd. C 75.57, H 5.55; found
C 75.69, H 5.41.
1
1075 cm–1. H NMR (400 MHz, CDCl3): δ = 7.79 (d, J = 9.2 Hz,
1 H), 7.44–7.41 (m, 3 H), 7.40–7.35 (m, 3 H), 7.31–7.29 (m, 1 H),
7.27–7.23 (m, 1 H), 2.44 (s, 3 H) ppm. 13C NMR (100 MHz,
CDCl3): δ = 157.8, 156.4, 152.4, 151.8, 130.4, 130.1, 130.0, 128.3,
127.9, 124.4, 120.7, 120.6, 117.2, 112.9, 109.7, 12.7 ppm. C18H12O3
(276.29): calcd. C 78.25, H 4.38; found C 78.42, H 4.21.
3-(Benzo[d][1,3]dioxol-5-yl)-2,6-dimethyl-4H-furo[3,2-c]pyran-4-one
2-Methyl-3-(p-tolyl)-4H-furo[3,2-c]chromen-4-one (4ab): White so-
(5ad): Yellow oil (93 mg, 66%). IR (KBr): ν = 3042, 1701,
˜
lid (110 mg, 76%). M.p. 139–141 °C. IR (KBr): ν = 3067, 1730,
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1
1103 cm–1. H NMR (400 MHz, CDCl3): δ = 7.18 (s, 1 H), 6.88–
1
1068 cm–1. H NMR (400 MHz, CDCl3): δ = 7.80 (d, J = 9.2 Hz,
6.84 (m, 1 H), 6.82–6.77 (m, 1 H), 6.29 (s, 1 H), 5.91 (s, 2 H), 2.32
(s, 3 H), 2.25 (s, 3 H) ppm. 13C NMR (100 MHz, CDCl3): δ =
160.7, 159.5, 159.3, 149.8, 147.2, 124.0, 123.5, 118.9, 110.4, 108.2,
105.7, 101.5, 101.2, 95.6, 20.2, 12.5 ppm. C16H12O5 (284.27): calcd.
C 67.60, H 4.25; found C 67.42, H 4.39.
1 H), 7.43–7.39 (m, 1 H), 7.36–7.31 (m, 3 H), 7.27–7.23 (m, 1 H),
7.20–7.18 (m, 2 H), 2.44 (s, 3 H), 2.33 (s, 3 H) ppm. 13C NMR
(100 MHz, CDCl3): δ = 157.9, 156.3, 152.4, 151.5, 137.7, 130.3,
129.8, 129.6, 129.1, 127.1, 124.4, 120.7, 117.2, 112.9, 109.8, 21.4,
12.7 ppm. C19H14O3 (290.32): calcd. C 78.61, H 4.86; found C
78.79, H 4.71.
Acknowledgments
3-(4-Methoxyphenyl)-2-methyl-4H-furo[3,2-c]chromen-4-one (4ac):
Gummy mass (110 mg, 72%). IR (KBr): ν = 3058, 1738, 1078 cm–1.
˜
1H NMR (400 MHz, CDCl3): δ = 7.90 (d, J = 9.2 Hz, 1 H), 7.52–
7.49 (m, 1 H), 7.47–7.44 (m, 3 H), 7.38–7.34 (m, 1 H), 7.02 (d, J
= 8.8 Hz, 2 H), 3.88 (s, 3 H), 2.54 (s, 3 H) ppm. 13C NMR
(100 MHz, CDCl3): δ = 159.3, 158.0, 156.3, 152.4, 151.4, 131.2,
130.3, 124.4, 122.3, 120.7, 120.2, 117.2, 113.9, 113.0, 109.9, 55.4,
12.7 ppm. C19H14O4 (306.32): calcd. C 74.50, H 4.61; found C
74.38, H 4.79.
A. H. acknowledges financial support from the Council of Scien-
tific and Industrial Research (CSIR), New Delhi [grant no.
02(0168)/13/EMR-II]. M. G. thanks the University Grants Com-
mission [UGC (SRF)], India for a senior research fellowship.
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1983, 52, 246; d) R. D. H. Murray, Prog. Chem. Org. Nat. Prod.
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Kang, K. Y. Lee, S. H. Sung, M. J. Park, Y. C. Kim, J. Nat.
3-(Benzo[d][1,3]dioxol-5-yl)-2-methyl-4H-furo[3,2-c]chromen-4-one
(4ad): Yellow solid (108 mg, 68%). M.p. 159–161 °C. IR (KBr): ν
˜
= 3068, 1739, 1079 cm–1. 1H NMR (400 MHz, CDCl3): δ = 7.80
(d, J = 9.2 Hz, 1 H), 7.42–7.40 (m, 1 H), 7.36–7.34 (m, 1 H), 7.31–
7.24 (m, 2 H), 6.88–6.81 (m, 2 H), 5.91 (s, 2 H), 2.43 (s, 3 H) ppm.
13C NMR (100 MHz, CDCl3): δ = 157.9, 156.3, 152.4, 151.6, 147.6,
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Eur. J. Org. Chem. 2015, 7836–7841