LETTER
Assembly of 1,3-Dihydro-2H-3-benzazepin-2-one Conjugates
1165
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was not detected in accordance with the observation in the
reaction of the simple substrates 11.7b
In summary, we have developed a novel sequence for syn-
thesis of the conjugates of 1,3-dihydro-2H-3-benzazepin-
2-ones with dibenz[b,f][1,4]oxazepine-11(10H)-ones by
taking advantage of the one-pot microwave-assisted U-
4CR–SNAr protocol9b and the palladium-catalyzed in-
tramolecular hydroamidation of arylalkynes.7 The current
work expands the scope of our studies on skeletal diversi-
ty of the C–N-bond-linked conjugates of various benzan-
nulated heterocycles.9a–9c These helical molecules show
atropisomerism and their flexible molecular architectures
may be of interest for chemical genetics studies.19
(11) Wu, J.; Nie, L.; Luo, J.; Dai, W.-M. Synlett 2007, 2728.
(12) For a recent review on benzannulated medium-ring
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Supporting Information for this article is available online at
Acknowledgment
The Laboratory of Asymmetric Catalysis and Synthesis is esta-
blished under the Cheung Kong Scholars Program of The Ministry
of Education of China. This work is supported in part by the rese-
arch grants from The National Natural Science Foundation of China
(Grant No. 20672092), Zhejiang University, and Zhejiang Univer-
sity Education Foundation.
References and Notes
(17) General Procedure for the Synthesis of 10a–g
A 10 mL pressurized process vial was charged with 0.25
mmol each of 2-aminophenol 5, 2-alknylbenzaldehyde 6, 2-
chloro-5-nitrobenzoic acid (7), and benzyl isocyanide (8),
and MeOH (2 mL). The loaded vial was then sealed with a
cap containing a silicon septum, and put into the microwave
cavity, and heated at 80 °C for 20 min. Then, an aq soln of
K2CO3 (1 mL, 0.30 mmol) was added to the reaction vial
through a syringe followed by heating at 100 °C for 10 min
in the microwave cavity. Water was added to the reaction
mixture, and the organic layer was extracted with EtOAc
(3 × 10 mL). The combined organic layer was washed with
brine, dried over anhyd Na2SO4, and evaporated under
reduced pressure. The residue was purified by column
chromatography over SiO2 with elution by 20% EtOAc in
PE (60–90 °C) to afford 10. The structures and yields of the
products 10a–g are given in Table 1.
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Characterization Data for Compound 10c
White crystalline solid; mp 149–151 °C (CH2Cl2–hexane).
Rf = 0.45 (20% EtOAc–hexane). IR (KBr): 3399, 3322,
2964, 2230, 1651, 1529, 1345, 1272, 1225 cm–1. 1H NMR
(400 MHz, CDCl3): d = 8.84 (d, J = 2.4 Hz, 1 H), 8.28 (dd,
J = 8.4, 2.4 Hz, 1 H), 7.59–7.55 (m, 1 H), 7.45 (br s, 1 H),
7.37–7.25 (m, 7 H), 7.18–7.12 (m, 2 H), 7.04 (d, J = 8.8 Hz,
1 H), 7.00 (dd, J = 8.8, 2.4 Hz, 1 H), 6.41 (br s, 1 H), 6.35 (t,
J = 5.6 Hz, 1 H), 4.66 and 4.59 (ABqd, J = 14.8, 6.0 Hz, 2
H), 2.21 (t, J = 7.2 Hz, 2 H), 1.48–1.37 (m, 2 H), 1.11 (s, 9
H), 0.88 (t, J = 7.6 Hz, 3 H). 13C NMR (100 MHz, CDCl3):
d = 168.9, 165.4, 165.2, 151.9, 148.9, 144.7, 137.8, 135.4
(br), 132.4, 129.7 (br), 129.0, 128.6 (2×), 128.4, 128.3, 127.6
(2×), 127.5, 127.4, 127.2, 124.9, 124.2, 121.1, 120.2, 97.4,
77.6, 66.6, 43.9, 34.4, 31.0 (3×), 21.9, 21.4, 13.5 (two
aromatic carbons were not seen). MS (+ESI): m/z (%) = 624
(100) [M + Na+]. Anal. Calcd for C37H35N3O5: C, 73.86; H,
5.86; N, 6.98. Found: C, 73.85; H, 5.83; N, 7.01.
(7) For formation of seven-membered-ring heterocycles, see:
(a) Tsubakiyama, M.; Sato, Y.; Mori, M. Heterocycles 2004,
Synlett 2009, No. 7, 1162–1166 © Thieme Stuttgart · New York