258
A. Srinivasa et al.
on a JEOL SX 102=DA-6000 (10 kV) FAB mass spectrometer.
The compounds 3a–3d [21a] and 6a–6f [21b] are known,
their identity were proven by means of IR, NMR, and mass
spectra. Herein we describe melting points and spectral data
for 3e–3h, which could not be found in literature.
128.3, 122.5, 119.7, 114.9, 55.5, 47.2, 42.3, 34.4, 32.1,
18.2 ppm; MS: m=z ¼ 327 (M þ 1).
cis-6-Bromo-2-phenyl-4-(20-oxopyrrolidinyl-10)-1,2,3,4-tetra-
hydroquinoline (3h, C19H19BrN2O)
Colorless crystalline solid, mp 185–187ꢃC; IR (KBr): ꢀꢀ¼
3315 (NH) cmꢄ1
;
1H NMR (CDCl3): ꢁ ¼ 2.08–2.22 (m,
Synthesis of 2-Aryl-4-(20-oxopyrrolidinyl-10)-1,2,3,4-tetra-
hydroquinolines 3
4H), 2.29–2.48 (m, 2H), 3.15–3.21 (m, 2H), 4.12 (brs, NH),
4.38 (dd, J ¼ 10.6, 2.8Hz, 1H), 5.38 (dd, J ¼ 11.6, 5.9 Hz,
1H), 6.50 (d, J ¼ 7.8Hz, 1H), 7.2 (dd, J ¼ 7.6, 2.6 Hz, 1H),
7.32–7.44 (m, 5H), 7.48 (s, 1H) ppm; 13C NMR (CDCl3):
ꢁ ¼ 175.8, 144.1, 140.7, 128.3, 127.9, 127.6, 127.2, 126.9,
123.1, 121.6, 116.6, 56.6, 49.1, 42.3, 35.1, 31.6, 18.8 ppm;
MS: m=z ¼ 373 (Mþ 1).
To a mixture of 1.0 mmol arylamines 1 and 122.3 mg N-
vinylpyrrolidin-2-one (2) (1.1mmol) in 10 cm3 acetonitrile,
791.5mg Sb2(SO4)3 (0.15 mmol) was added. The reaction
mixture was stirred at room temperature for the appropriate
time. The reaction was monitored by TLC (petroleum ether:-
ethyl acetate). After completion of reaction, the reaction mix-
ture was filtered to remove the catalyst and washed with 3 cm3
of acetone. Then the clear filtrate was poured into 50cm3
water and extracted with ethyl acetate (3ꢂ10cm3). The com-
bined organic layer washed with 10cm3 brine, followed by
10cm3 water and dried over anhydrous Na2SO4, then concen-
trated under reduced pressure. The residue, thus obtained was
purified by column chromatography using silica gel (60–120
mesh) and eluted with petroleum ether:ethyl acetate to afford
tetrahydroquinolines 3.
One-Pot Synthesis of 2-(3-Nitrophenyl-4-(20-oxopyrrolidinyl-
10)-1,2,3,4-tetrahydroquinoline 6
A mixture of 1.0 mmol arylamines 4 and 151.1 mg 3-nitro-
benzaldehyde (5) (1.0mmol) in 10cm3 CH3CN was stirred at
room temperature for 1 h in presence of 166.3mg Sb2(SO4)3
(0.20 mmol), followed by addition of 111.0 mg 2 (1.0mmol)
drop by drop over a period of 2 min. The resulting reaction
mixture were stirred at room temperature for the appropriate
time. The reaction was monitored by TLC. After completion of
reaction, the reaction mixture was filtered to remove the catalyst
and washed with 3 cm3 of acetone. Then the clear filtrate was
poured into 50cm3 water and extracted with ethyl acetate
(3ꢂ10 cm3). The combined organic layer was washed with
10cm3 brine, followed by 10 cm3 water, and dried over anhy-
drous Na2SO4, then concentrated under reduced pressure. The
residue thus obtained was purified by column chromatography
using silica gel (60–120 mesh) and eluted with petroleum
ether:ethyl acetate to afford tetrahydroquinolines 6.
cis-6-Methyl-2-phenyl-4-(20-oxopyrrolidinyl-10)-1,2,3,4-tetra-
hydroquinoline (3e, C20H22N2O)
Colorless crystalline solid, mp 164–166ꢃC; IR (KBr): ꢀꢀ¼
1
3356 (NH) cmꢄ1; H NMR (CDCl3): ꢁ ¼ 1.96–2.01 (m, 2H),
2.05–2.09 (m, 2H), 2.26 (s, 3H), 2.41–2.52 (m, 2H), 3.17–
3.28 (m, 2H), 4.02(brs, NH), 4.55 (dd, J ¼ 9.0, 3.9 Hz, 1H), 5.22
(dd, J ¼ 10.8, 6.4 Hz, 1H), 6.61 (d, J ¼ 8.1 Hz, 1H), 6.99 (dd,
J ¼ 8.1, 2.8 Hz, 1H), 7.25 (d, J ¼ 6.6 Hz, 1H), 7.33–7.51 (m,
5H) ppm; 13C NMR (CDCl3): ꢁ ¼ 175.6, 143.1, 142.5, 129.5,
129.4, 128.7, 127.9, 127.7, 126.6, 122.2, 121.8, 118.4, 55.3,
48.1, 42.8, 35.5, 31.3, 21.4, 18.2ppm; MS: m=z ¼ 306 (Mþ).
References
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CS, Saggers JA, Michelotti EL, Tice CM (2003) Bioorg
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6462
cis-8-Methyl-2-phenyl-4-(20-oxopyrrolidinyl-10)-1,2,3,4-tetra-
hydroquinoline (3f, C20H22N2O)
Colorless crystalline solid, mp 172–174ꢃC; IR (KBr): ꢀꢀ¼
3348 (NH) cmꢄ1
;
1H NMR (CDCl3): ꢁ ¼ 2.01–2.05 (m,
2H), 2.09–2.15 (m, 3H), 2.45–2.55 (m, 2H), 3.18–3.33 (m,
2H), 4.09 (brs, NH), 4.35 (dd, J ¼ 8.6, 3.8 Hz, 1H), 5.24 (dd,
J ¼ 11.2, 2.8Hz, 1H), 6.65 (t, J ¼ 7.6 Hz, 1H), 7.12 (d, J ¼
7.8 Hz, 1H), 7.29–7.42 (m, 6H) ppm; 13C NMR (CDCl3):
ꢁ ¼ 175.4, 141.9, 141.0, 129.3, 129.2, 128.8, 128.1, 127.8,
121.9, 118.1, 117.0, 55.1, 47.6, 42.1, 34.6, 31.1, 20.9,
18.22 ppm; MS: m=z ¼ 322 (Mþ).
cis-2-(4-Chlorophenyl)-4-(20-oxopyrrolidinyl-10)-1,2,3,4-tetra-
hydroquinoline (3g, C19H19ClN2O)
Colorless crystalline solid, mp 148–150ꢃC; IR (KBr):
1
ꢀꢀ¼ 3328 (NH) cmꢄ1; H NMR (CDCl3): ꢁ ¼ 2.04–2.09 (m,
2H), 2.11–2.15 (m, 2H), 2.45–2.52 (m, 2H), 3.19–3.34 (m,
2H), 4.10 (brs, NH), 4.26 (dd, J ¼ 8.8, 3.8 Hz, 1H), 5.21 (dd,
J ¼ 11.8, 2.6 Hz, 1H), 6.77 (t, J ¼ 7.4, 1.0 Hz, 1H), 7.13 (dt,
J ¼ 7.4, 1.7 Hz, 1H), 7.25–7.54 (m, 6H) ppm; 13C NMR
(CDCl3): ꢁ ¼ 175.4, 144.7, 140.6, 132.2, 130.0, 129.5, 128.7,