The Journal of Organic Chemistry
Article
67.0, 56.1, 56.0, 52.2, 51.7, 42.7. HRMS (ESI) m/z: [M + H]+ calcd
for C26H26NO8, 480.1653; found, 480.1655.
3-Benzyl 1,2-Dimethyl 7-Bromo-5,6-dihydropyrrolo[2,1-a]-
isoquinoline-1,2,3-tricarboxylate (3j). Eluent: petroleum ether/
131.9, 130.9, 129.9, 129.6, 129.0, 121.7, 113.1, 63.6, 55.0, 54.4, 45.2,
31.9, 16.6. HRMS (ESI) m/z: [M + H]+ calcd for C19H20NO6,
358.1285; found, 358.1291.
Triethyl 5,6-Dihydropyrrolo[2,1-a]isoquinoline-1,2,3-tricarboxy-
late (3f). Eluent: petroleum ether/ethyl acetate: 50/1 to 2/1.
ethyl acetate: 50/1 to 2/1. White solid, 129 mg, 87%. mp 143−144
1
°C; H NMR (300 MHz, chloroform-d): δ 8.10 (d, J = 7.9 Hz, 1H),
7.56 (d, J = 8.0 Hz, 1H), 7.47−7.29 (m, 5H), 7.19 (t, J = 8.0 Hz, 1H),
5.28 (s, 2H), 4.56 (t, J = 6.6 Hz, 2H), 3.79 (s, 3H), 3.55 (s, 3H), 3.17
(t, J = 6.6 Hz, 2H). 13C{1H} NMR (75 MHz, chloroform-d): δ 166.1,
163.6, 159.4, 135.8, 135.0, 133.9, 133.2, 128.6, 128.5, 128.0, 127.5,
127.2, 123.1, 118.7, 67.2, 52.2, 51.8, 42.1, 29.0. HRMS (ESI) m/z: [M
+ H]+ calcd for C24H21NO6Br, 498.0547; found, 498.0555.
1
Colorless oil, 87 mg, 75%; H NMR (300 MHz, chloroform-d): δ
8.26−8.15 (m, 1H), 7.38−7.22 (m, 3H), 4.70−4.52 (m, 2H), 4.47−
4.27 (m, 6H), 3.02 (t, J = 6.6 Hz, 2H), 1.54−1.27 (m, 9H). 13C{1H}
NMR (75 MHz, chloroform-d): δ 166.0, 163.4, 159.8, 136.6, 134.2,
129.2, 128.4, 127.2, 126.9, 126.4, 119.0, 110.8, 61.4, 60.9, 60.7, 42.6,
29.3, 14.1, 14.0. HRMS (ESI) m/z: [M + H]+ calcd for C21H24NO6,
386.1598; found, 386.1606.
3-Benzyl 1-Methyl 5,6-Dihydropyrrolo[2,1-a]isoquinoline-1,3-
dicarboxylate (3k). Eluent: petroleum ether/ethyl acetate: 50/1 to
3-(tert-Butyl) 1,2-Dimethyl 5,6-Dihydropyrrolo[2,1-a]-
isoquinoline-1,2,3-tricarboxylate (3g). Eluent: petroleum ether/
2/1. Colorless oil, 77 mg, 71%; 1H NMR (300 MHz, chloroform-d): δ
8.53−8.44 (m, 1H), 7.82−6.80 (m, 10H), 5.35 (d, J = 2.1 Hz, 2H),
4.65 (t, J = 6.6 Hz, 2H), 3.89 (s, 3H), 3.05 (t, J = 6.6 Hz, 2H).
13C{1H} NMR (75 MHz, chloroform-d): δ 164.8, 160.6, 138.1, 136.1,
134.0, 129.0, 128.6, 128.5, 128.2, 127.3, 127.0, 121.7, 120.8, 112.1,
66.0, 51.4, 42.4, 29.4. HRMS (ESI) m/z: [M + H]+ calcd for
C22H20NO4, 362.1387; found, 362.1393.
3-Ethyl 1-Methyl 5,6-Dihydropyrrolo[2,1-a]isoquinoline-1,3-di-
carboxylate (3l). Eluent: petroleum ether/ethyl acetate: 50/1 to 2/
ethyl acetate: 50/1 to 2/1. White solid, 92 mg, 80%. mp 115−117
°C; 1H NMR (300 MHz, chloroform-d): δ 8.21−8.12 (m, 1H), 7.40−
7.24 (m, 3H), 4.55 (t, J = 6.5 Hz, 2H), 3.95 (s, 3H), 3.86 (s, 3H),
3.03 (t, J = 6.5 Hz, 2H), 1.59 (s, 9H). 13C{1H} NMR (75 MHz,
chloroform-d): δ 166.5, 163.9, 159.1, 136.2, 134.2, 129.1, 128.2,
127.3, 126.9, 126.5, 126.0, 120.3, 110.3, 82.5, 52.3, 51.7, 42.5, 29.4,
28.1. HRMS (ESI) m/z: [M + H]+ calcd for C21H24NO6, 386.1598;
found, 386.1604.
3-(tert-Butyl) 1,2-Diethyl 5,6-Dihydropyrrolo[2,1-a]isoquinoline-
1,2,3-tricarboxylate (3h). Eluent: petroleum ether/ethyl acetate: 50/
1
1. White solid, 59 mg, 66%. mp 90−92 °C; H NMR (300 MHz,
chloroform-d): δ 8.49−8.28 (m, 1H), 7.52 (s, 1H), 7.43−7.20 (m,
3H), 4.62 (t, J = 6.6 Hz, 2H), 4.34 (q, J = 7.1 Hz, 2H), 3.88 (s, 3H),
3.04 (t, J = 6.6 Hz, 3H), 1.40 (t, J = 7.1 Hz, 4H). 13C{1H} NMR (75
MHz, chloroform-d): δ 164.9, 160.9, 137.8, 134.0, 128.8, 128.4, 127.2,
126.9, 121.3, 111.9, 60.3, 51.3, 42.3, 29.4, 14.3. HRMS (ESI) m/z: [M
+ H]+ calcd for C17H18NO4, 300.1230; found, 300.1237.
1 to 2/1. White solid, 100 mg, 81%. mp 129−131 °C; 1H NMR (300
MHz, chloroform-d): δ 8.52−7.49 (m, 1H), 7.48−6.78 (m, 3H), 4.54
(t, J = 6.5 Hz, 2H), 4.45−4.37 (m, 2H), 4.37−4.30 (m, 2H), 3.02 (t, J
= 6.5 Hz, 2H), 1.59 (s, 9H), 1.44 (t, J = 7.2 Hz, 3H), 1.36 (t, J = 7.1
Hz, 3H). 13C{1H} NMR (75 MHz, chloroform-d): δ 166.0, 163.6,
159.2, 136.1, 134.2, 129.0, 128.3, 127.2, 126.8, 126.6, 126.1, 120.3,
82.4, 61.3, 60.6, 42.5, 29.4, 28.1, 14.1, 14.0. HRMS (ESI) m/z: [M +
H]+ calcd, for C23H28NO6, 414.1911; found, 414.1919.
3-Benzyl 1-Methyl 8,9-Dimethoxy-5,6-dihydropyrrolo[2,1-a]-
isoquinoline-1,3-dicarboxylate (3m). Eluent: petroleum ether/ethyl
3-Benzyl 1,2-Dimethyl 8,9-Dimethoxy-5,6-dihydropyrrolo[2,1-a]-
isoquinoline-1,2,3-tricarboxylate (3i). Eluent: petroleum ether/ethyl
acetate: 50/1 to 2/1. Yellow solid, 37 mg, 29%. mp 128−130 °C; 1H
NMR (300 MHz, chloroform-d): δ 8.39 (s, 1H), 7.53−7.35 (m, 5H),
6.78 (s, 1H), 5.34 (s, 2H), 4.64 (t, J = 6.7 Hz, 2H), 4.01 (s, 3H), 3.96
(s, 3H), 3.88 (s, 3H), 3.00 (t, J = 6.7 Hz, 2H). 13C{1H} NMR (75
MHz, chloroform-d): δ 164.9, 160.6, 149.5, 147.6, 138.5, 136.1, 128.6,
128.2, 128.1, 127.2, 120.3, 119.8, 112.3, 111.1, 110.3, 65.9, 56.1, 55.9,
51.4, 42.5, 28.9. HRMS (ESI) m/z: [M + H]+ calcd for C24H24NO6,
422.1598; found, 422.1604.
Benzyl 9,14-Dioxo-5,6,9,14-tetrahydrobenzo[5,6]isoindolo[1,2-
a]isoquinoline-8-carboxylate (3n). Eluent: petroleum ether/ethyl
acetate: 50/1 to 2/1. Yellow solid, 78 mg, 60%. mp 174−179 °C; 1H
NMR (300 MHz, chloroform-d): δ 9.46−8.76 (m, 1H), 8.46−8.17
(m, 2H), 7.80−7.64 (m, 2H), 7.60 (d, J = 7.1 Hz, 2H), 7.53−7.35 (m,
acetate: 50/1 to 2/1. White solid, 120 mg, 85%. mp 102−104 °C; 1H
NMR (300 MHz, chloroform-d): δ 8.04 (s, 1H), 7.49−7.31 (m, 5H),
6.76 (s, 1H), 5.28 (s, 2H), 4.58 (t, 2H), 3.94 (s, 6H), 3.81 (s, 3H),
3.56 (s, 3H), 2.96 (t, J = 6.6 Hz, 2H). 13C{1H} NMR (75 MHz,
chloroform-d): δ 166.6, 163.8, 159.6, 149.9, 147.6, 137.6, 135.2,
128.8, 128.4, 127.6, 127.5, 124.4, 123.5, 119.0, 118.1, 112.2, 110.3,
G
J. Org. Chem. XXXX, XXX, XXX−XXX