E
X.-L. Chen et al.
Letter
Synlett
(14) (a) Leyva, E.; Baines, K. M.; Espinosa-González, C. G.; Magaldi-
Lara, D. A.; Loredo-Carrillo, S. E.; De Luna-Méndez, T. A.; López,
L. I. J. Fluorine Chem. 2015, 180, 152. (b) da Silva Lisboa, C.;
Santos, V. G.; Vaz, B. G.; de Lucas, N. C.; Eberlin, M. N.; Garden, S.
J. J. Org. Chem. 2011, 76, 5264.
(15) Huang, H.-M.; Li, Y.-J.; Dai, Y.-P.; Yu, W.-B.; Ye, Q.; Gao, J.-R. J. Chem.
Res. 2013, 37, 34.
(16) Sharma, U.; Katoch, D.; Sood, S.; Kumar, N.; Singh, B.; Thakur,
A.; Gulati, A. Indian J. Chem. 2013, 52B, 1431.
with Na2SO4, filtered, and concentrated under reduced pressure.
The resulting crude product was then purified by column chro-
matography (petroleum ether/EtOAc 5:1) on silica gel to afford
the desired product as red solid (yield: 93%), mp 184–187 °C. 1H
NMR (400 MHz, CDCl3): = 8.21–8.03 (m, 2 H), 7.84–7.70 (m, 1
H), 7.73–7.61 (m, 1 H), 7.57 (s, 1 H), 7.43 (t, J = 7.9 Hz, 2 H), 7.26
(t, J = 7.4 Hz, 3 H), 7.21 (d, J = 7.3 Hz, 1 H), 6.42 (s, 1 H). 13C NMR
(101 MHz, CDCl3): = 183.92, 182.05, 144.69, 137.41, 134.91,
133.18, 132.34, 130.34, 129.68, 126.51, 126.14, 125.60, 122.58,
103.36.
(17) Couladouros, E. A.; Plyta, A. F.; Papageorgiou, V. P. J. Org. Chem.
1996, 61, 3031.
(28) Reaction on Gram Scale
(18) Leyva, E.; Baines, K. M.; Espinosa-González, C. G.; López, L. I.;
Magaldi-Lara, D. A.; Leyva, S. Tetrahedron Lett. 2015, 56, 5248.
(19) Wang, X. L.; Zheng, X. F.; Wang, L.; Reiner, J.; Xie, W. L.; Chang, J.
B. Synthesis 2007, 989.
(20) Chen, X.-L.; Ai, B.-R.; Dong, Y.; Zhang, X.-M.; Wang, J.-Y. Tetrahe-
dron Lett. 2017, 58, 3646.
(21) (a) Li, C. J. Chem. Rev. 1993, 93, 2023. (b) Butler, R. N.; Coyne, A.
G. Chem. Rev. 2010, 110, 6302. (c) Simon, M.-O.; Li, C.-J. Chem.
Soc. Rev. 2012, 41, 1415.
(22) Sridharan, V.; Martín, M. A.; Menéndez, J. C. Eur. J. Org. Chem.
2009, 4614.
To a solution of 1,4-naphthoquinone (1a) (2.3 g, 15 mmol, 1
equiv), 1-methoxy-4-nitrobenzene (2c) (18 mmol, 1.2 equiv),
Zn(OAc)2·2H2O (3 mmol, 20 mol%), Zn (75 mmol, 5 equiv) in
H2O (30 mL) was added AcOH (0.2 mol, 15 equiv). The resulting
mixture was stirred for 5 h at rt. Then, the reaction mixture was
diluted with water and extracted with EtOAc (3×80 mL). The
combined organic layers were washed with brine, dried with
Na2SO4, filtered, and concentrated under reduced pressure. The
resulting crude product was then purified by column chroma-
tography (petroleum ether/EtOAc 5:1) on silica gel to afford the
desired product 3ac (yield: 2.9 g, 71%).
(23) Singh, P. P.; Aithagani, S. K.; Yadav, M.; Singh, V. P.;
Vishwakarma, R. A. J. Org. Chem. 2013, 78, 2639.
(29) Synthesis of 2-Methoxy-5H-benzo[b]carbazole-6,11-dione
(4ac)26
(24) Moon, Y.; Jeong, Y.; Kook, D.; Hong, S. Org. Biomol. Chem. 2015,
13, 3918.
(25) Sieveking, I.; Thomas, P.; Estévez, J. C.; Quiñones, N.; Cuéllar, M.
A.; Villena, J.; Espinosa-Bustos, C.; Fierro, A.; Tapia, R. A.; Maya, J.
D.; López-Muñoz, R.; Cassels, B. K.; Estévez, R. J.; Salas, C. O.
Bioorg. Med. Chem. 2014, 22, 4609.
To a solution of 2-(4-methoxyphenylamino)naphthalene-1,4-
dione (3ac) (0.13 g, 0.5 mmol, 1 equiv) in DMF (2.0 mL) were
added Pd(OAc)2 (0.1 mmol, 0.2 equiv) and Cu(OAc)2 (1.25 mmol,
2.5 equiv). The resulting mixture was stirred for 24 h at 120 °C.
Then, the reaction mixture was cooled to rt, diluted with water
and extracted with EtOAc (3×20 mL). The combined organic
layers were washed with water, brine, dried with Na2SO4, fil-
tered, and concentrated under reduced pressure. The resulting
crude product was then purified by column chromatography
(petroleum ether/EtOAc 1:1) on silica gel to afford the desired
product 4ac as a yellow solid (yield: 90.1 mg, 65%), mp 300–305
°C. 1H NMR (400 MHz, DMSO-d6): = 13.00 (s, 1 H), 8.08 (t,
J = 7.3 Hz, 2 H), 7.81 (d, J = 19.1 Hz, 2 H), 7.59 (d, J = 2.1 Hz, 1 H),
7.47 (d, J = 9.0 Hz, 1 H), 7.07 (dd, J = 9.0, 2.3 Hz, 1 H), 3.84 (s, 3
H). 13C NMR (101 MHz, DMSO-d6): = 180.06, 177.02, 156.76,
136.82, 133.98, 133.25, 132.96, 132.55, 125.83, 124.65, 118.24,
116.82, 114.80, 101.91, 55.20.
(26) Mandal, A.; Mondal, S. K.; Jana, A.; Manna, S. K.; Ali, Sk. A.;
Samanta, S. J. Heterocyclic Chem. 2017, 54, 2529.
(27) Typical Procedure: Preparation of 2-(Phenylamino)naphtha-
lene-1,4-dione (3aa)25
To a solution of 1,4-naphthoquinone (0.3 mmol, 1 equiv), nitro-
benzene (0.36 mmol, 1.2 equiv), Zn(OAc)2·2H2O (0.06 mmol, 20
mol%), Zn (1.5 mmol, 5 equiv) in H2O (0.6 mL) was added AcOH
(4.5 mmol, 15 equiv). The resulting mixture was stirred for 5 h
at rt. Then, the reaction mixture was diluted with water, filtered
to remove the residual Zn dust, extracted with EtOAc (3×5 mL).
The combined organic layers were washed with brine, dried
© Georg Thieme Verlag Stuttgart · New York — Synlett 2019, 30, A–E