Synlett 2006(6): 942-944  
DOI: 10.1055/s-2006-939047
LETTER
© Georg Thieme Verlag Stuttgart · New York

Palladium-Catalyzed Amination of 2,3-Dichloro-1,4-naphthoquinone with Nitroarylamines

Xiao-Lei Wang, Xiu-Fang Zheng, John Reiner*
College of Pharmaceuticals and Biotechnology, Tianjin University, Tianjin 300072, P. R. of China
Fax: +86(022)27890968; e-Mail: jreiner@tju.edu.cn;
Further Information

Publication History

Received 11 January 2006
Publication Date:
14 March 2006 (online)

Abstract

A convenient one-step synthesis of 2-[(nitroaryl)amino]-3-chloro-1,4-naphthoquinones is reported. The direct amination of 2,3-dichloro-1,4-naphthoquinone with nitro-substituted aryl amines is catalyzed by PdCl2(dppf)/dppf [1] in the presence of t-BuONa as base to yield 2-[(nitroaryl)amino]-3-chloro-1,4-naphthoquinones, several of which were previously unavailable. Traces of the 2,3-di[(nitroaryl)amino]-1,4-naphthoquinones were detected as side products.

1

dppf = 1,1′-bis(diphenylphosphino)ferrocene.

1

dppf = 1,1′-bis(diphenylphosphino)ferrocene.

15

General Experimental Procedure. A mixture of 2,3-dichloro-1,4-naphthoquinone (200 mg, 0.88 mmol), nitroarylamine (0.97 mmol), t-BuONa (1.01 mmol), PdCl2(dppf) (0.04 mmol), and dppf (0.04 mmol) in 5 mL toluene were stirred under a nitrogen atmosphere at 80 °C for 12 h, and then the reaction was concentrated and the products were purified by column chromatography (40-80% CH2Cl2-PE).

16

1H NMR and 13C NMR spectra were recorded on a Varian Inova 500 MHz instrument.
Compound 2a: [14] 1H NMR (CDCl3): δ = 8.22-8.25 (m, 3 H), 8.16 (dd, J = 7.5, 1.0 Hz, 1 H), 7.82 (dt, J = 7.5, 1.5 Hz, 1 H), 7.76 (dt, J = 7.5, 1.5 Hz, 1 H), 7.71 (s, 1 H), 7.08 (dd, J = 7.0, 2.0 Hz, 2 H).
Compound 3a: 1H NMR (DMSO-d 6): δ = 8.06 (dd, J = 5.5, 3.5 Hz, 2 H), 7.84 (dd, J = 5.5, 3.0 Hz, 2 H), 7.74 (dd, J = 7.5, 2.0 Hz, 4 H), 6.56 (t, 4 H). 13C NMR (DMSO-d 6): δ = 181.61, 145.08, 140.32, 134.75, 131.83, 126.67, 126.30, 124.02, 119.06.
Compound 2b: 1H NMR (CDCl3): δ = 8.57 (d, J = 2.5 Hz, 1 H), 8.39 (dd, J = 9.0, 2.5 Hz, 1 H), 8.23 (dd, J = 7.5, 1.0 Hz, 1 H), 8.17 (dd, J = 7.5, 1.0 Hz, 1 H), 7.87 (s, 1 H), 7.84 (td, J = 7.5, 1.5 Hz, 1 H), 7.78 (td, J = 7.5, 1.5 Hz, 1 H), 7.04 (d, J = 8.5 Hz, 1 H). 13C NMR (CDCl3): δ = 179.56, 177.18, 143.22, 141.38, 140.24, 135.44, 133.98, 131.95, 129.79, 127.59, 127.39, 126.89, 124.95, 123.85, 122.82, 122.78, 122.73, 122.69, 122.53, 122.28, 121.68, 121.52.
Compound 3b: 1H NMR (CDCl3): δ = 8.40 (s, 2 H), 8.24 (m, 4 H), 8.13 (dd, J = 9.0, 2.0 Hz, 2 H), 7.85 (dd, J = 6.0, 3.5 Hz, 2 H), 6.56 (d, J = 9.0 Hz, 2 H). 13C NMR (CDCl3): δ = 180.55, 141.30, 139.97, 135.07, 130.50, 127.87, 127.37, 123.87, 122.76, 122.72, 122.67, 122.63, 121.68, 119.49, 118.47, 118.21.
Compound 2c: 1H NMR (CDCl3): δ = 8.26 (s, 2 H), 8.18 (m, 1 H), 8.12 (m, 1 H), 7.80 (td, J = 7.5, 1.5 Hz, 1 H), 7.74 (td, J = 7.5, 1.0 Hz, 1 H), 7.28 (s, 1 H). 13C NMR (CDCl3): δ = 178.88, 177.00, 145.36, 140.96, 140.00, 135.20, 133.57, 132.84, 131.99, 129.75, 127.31, 127.19, 123.44, 118.34.
Compound 2d: 1H NMR (DMSO-d 6): δ = 8.02-8.04 (m, 2 H), 7.90-7.92 (m, 2 H), 7.86 (td, J = 7.5, 1.0 Hz, 1 H), 7.81 (td, J = 7.5, 1.0 Hz, 1 H), 7.56 (t, J = 8.0, 1 H), 7.50 (dt, J = 8.0, 1.0 Hz, 1 H). 13C NMR (DMSO-d 6): δ = 180.47, 177.77, 148.16, 143.42, 140.98, 135.48, 134.24, 132.39, 131.09, 129.91, 129.79, 127.28, 126.90, 118.91, 117.98, 117.79.
Compound 3d: 1H NMR (DMSO-d 6): δ = 8.05 (dd, J = 6.0, 3.0 Hz, 2 H), 7.82 (J = 6.0, 3.0 Hz, 2 H), 7.42 (dd, J = 8.5, 1.5 Hz, 2 H), 7.06-7.11 (m, 4 H), 6.72 (dd, J = 8.5, 2.0 Hz, 2 H). 13C NMR (DMSO-d 6): δ = 181.58, 147.45, 139.23, 134.55, 131.89, 128.61, 126.53, 126.07, 124.88, 115.47, 114.24.
Compound 2e: [14] 1H NMR (CDCl3): δ = 8.20 (dd, J = 7.5, 1.0 Hz, 1 H), 8.14 (dd, J = 7.5, 1.0 Hz, 1 H), 7.80 (td, J = 7.5, 1.5 Hz, 1 H), 7.70-7.74 (m, 2 H), 7.63 (s, 1 H), 7.32 (d, J = 8.5 Hz, 1 H), 7.19 (dd, J = 8.0, 2.0 Hz, 1 H), 2.61 (s, 3 H).
Compound 3e: 1H NMR (DMSO-d 6): δ = 8.01 (dd, J = 5.5, 3.5 Hz, 2 H), 7.79 (dd, J = 5.5, 3.5 Hz, 2 H), 6.93 (d, J = 8.5 Hz, 2 H), 6.78 (d, J = 2.0 Hz, 2 H), 6.50 (dd, J = 8.0, 2.0 Hz, 2 H), 2.25 (s, 3 H). 13C NMR (DMSO-d 6): δ = 181.52, 148.03, 136.95, 134.43, 131.88, 131.35, 126.42, 125.08, 124.78, 124.50, 115.79, 19.42.
Compound 2f: [14] 1H NMR (DMSO-d 6): δ = 8.04 (dd, J = 8.0, 1.0 Hz, 2 H), 7.88 (td, J = 7.5, 1.5 Hz, 1 H), 7.82 (td, J = 7.5, 1.5 Hz, 1 H), 7.68 (d, J = 3.0 Hz, 1 H), 7.46 (dd, J = 9.0, 3.0 Hz, 1 H), 7.32 (d, J = 9.0 Hz, 1 H), 3.93 (s, 1 H). 13C NMR (DMSO-d 6): δ = 180.51, 177.53, 149.63, 143.83, 138.82, 135.53, 134.02, 132.50, 132.29, 130.90, 130.71, 127.24, 126.79, 120.91, 115.19, 114.44, 57.50.
Compound 3f: 1H NMR (DMSO-d 6): δ = 8.03 (dd, J = 5.5, 3.5 Hz, 2 H), 7.81 (dd, J = 5.5, 3.5 Hz, 2 H), 6.90 (d, J = 9.0 Hz, 2 H), 6.74 (d, J = 2.0 Hz, 2 H), 6.63 (dd, J = 9.0, 2.0 Hz, 2 H), 3.77 (s, 6 H). 13C NMR (DMSO-d 6): δ = 181.40, 147.50, 138.47, 134.34, 131.90, 131.19, 126.35, 126.17, 124.13, 116.39, 113.60, 57.51.
Compound 2g: 1H NMR (DMSO-d 6): δ = 8.04-8.07 (m, 2 H), 7.89 (td, J = 7.5, 1.5 Hz, 1 H), 7.84 (td, J = 7.5, 1.0 Hz, 1 H), 7.77 (d, J = 2.5 Hz, 1 H), 7.68 (d, J = 9.0 Hz, 1 H), 7.42 (dd, J = 9.0, 2.5 Hz, 1 H). 13C NMR (DMSO-d 6): δ = 180.38, 177.77, 147.65, 143.20, 140.04, 135.47, 134.31, 132.30, 131.60, 131.10, 128.07, 127.29, 126.91, 119.50, 119.28, 119.18.
Compound 2h: 1H NMR (CDCl3): δ = 9.49 (s, 1 H), 8.22 (dd, J = 6.5, 1.0 Hz, 1 H), 8.16-8.21 (m, 2 H), 7.81 (td, J = 8.0, 1.5 Hz, 1 H), 7.76 (td, J = 7.5, 1.0 Hz, 1 H), 7.58 (td, J = 8.0, 1.5 Hz, 1 H), 7.20 (td, J = 6.0, 1.0 Hz, 1 H), 6.90 (m, 1 H). 13C NMR (CDCl3): δ = 179.71, 177.41, 140.54, 139.46, 135.06, 133.77, 133.62, 133.61, 131.99, 130.19, 127.39, 127.31, 125.95, 124.08, 123.26, 121.88.
Compound 3h: 1H NMR (DMSO-d 6): δ = 8.10 (dd, J = 5.5, 3.0 Hz, 2 H), 7.86 (dd, J = 5.5, 2.5 Hz, 2 H), 7.68 (dd, J = 8.5, 1.5 Hz, 2 H), 7.27 (m, 2 H), 6.78 (m, 4 H). 13C NMR (DMSO-d 6): δ = 181.34, 137.02, 135.04, 134.42, 133.45, 131.66, 126.89, 125.66, 124.54, 122.33, 122.23.
Compound 2i: [14] 1H NMR (DMSO-d 6): δ = 8.86 (s, 1 H), 8.42 (d, J = 6.0 Hz, 1 H), 8.06-8.12 (m, 2 H), 7.90-7.95 (m, 2 H), 7.40 (d, J = 9.0 Hz, 1 H).