S1
Supporting Information
Direct Amination of Azoles via Catalytic C−H, N−H Coupling
Daiki Monguchi, Taiki Fujiwara, Hirotoshi Furukawa, and Atsunori Mori*
Department of Chemical Science and Engineering, Kobe University, 1-1
Rokkodai, Nada, Kobe 657-8501, Japan
Experimental Section
General. 1H NMR (500 MHz) and 13C NMR (125 MHz) spectra were measured on a
Brucker Avence 500 spectrometer. The chemical shifts were expressed in ppm with
CHCl3 (7.26 ppm for 1H) or CDCl3 (77.0 ppm for 13C) as internal standards. IR spectra
were recorded on PERKIN ELMER FT-IR Spectrometer SPECTRUM 1000. High
resolution mass spectra (HRMS, EI) were measured by JEOL JMS-700 MStation at the
Graduate School of Material Science, Nara Institute of Science and Technology. For
thin layer chromatoraphy (TLC) analyses throughout this work, Merck precorted TLC
plates (silica gel 60 F254) were used.
General procedure for the oxidative copper-catalyzed amination of heteroaromatic
compounds.
A solution of Cu(OAc)2 (7.3 mg, 0.04 mmol), PPh3 (21 mg, 0.08 mmol), benzothiazole
1a (22 μL, 0.2 mmol), N-methylaniline 2a (88 μL, 0.8 mmol) and NaOAc (66 mg, 0.8 mmol) in 1 mL of xylene was stirred at 140 ºC for 20 h under O2. After cooling to room
temperature, the mixture was passed through a Celite pad, which was washed with
chloroform repeatedly. The filtrate was washed with water three times. The organic
layer was concentrated under reduced pressure to leave a crude oil, which was purified
by column chromatography on silica gel to afford 39 mg of 3a as a colorless oil (81%).
N-Benzothiazol-2-yl-N-propyl-4-methylbenzenesulfonamide (3c): 1H NMR (500 MHz, CDCl3) δ 0.98 (t, J = 7.5 Hz, 3H), 1.78-1.86 (m,
2H), 2.37 (s, 3H), 4.00-4.03 (m, 2H), 7.24-7.29 (m, 3H), 7.36-7.39 (m,
1H), 7.74 (d, J = 9.1 Hz, 2H), 7.77 (d, J = 8.4 Hz, 2H); 13C NMR (125 MHz, CDCl3) δ
11.2, 21.7, 21.9, 51.8, 120.9, 121.7, 124.3, 126.1, 127.3, 130.1, 133.4, 135.6, 144.9,
N
SN
Ts
nPr
S2
149.7, 160.2; IR (neat) 1011, 1088, 1172, 1186, 1224, 1225, 1307, 1361, 1443, 1457,
1496, 1596, 1699, 2873, 2965, 3062 cm-1; HRMS found: m/z 346.0811. Calcd for
346.0810.
N-(4,5-Dimethyl-thiazol-2yl)-N-methylaniline (5a): 1H NMR (500
MHz, CDCl3) δ 2.14 (d, J = 0.6 Hz, 3H), 2.18 (d, J = 0.6 Hz, 3H),
3.48 (s, 3H), 7.16-7.23 (m, 1H), 7.33-7.43 (m, 4H); 13C NMR (125
MHz, CDCl3) δ 11.1, 14.9, 40.0, 114.4, 124.7, 125.9, 129.7, 147.0, 166.4; IR (neat)
1131, 1287, 1374, 1410, 1516, 1597, 1678, 2851, 2917, 3035 cm-1; HRMS found: m/z
218.0878. Calcd for 218.0878.
N-Benzoxazol-2-yl-diphenylamine (7b): 1H NMR (500 MHz,
CDCl3) δ 7.03 (t, J = 7.6 Hz, 1H), 7.14 (t, J = 7.7 Hz, 1H), 7.18-7.22
(m, 3H), 7.27-7.37 (m, 8H), 7.41 (d, J = 7.6 Hz, 1H); 13C NMR (125
MHz, CDCl3) δ 109.4, 117.7, 122.2, 124.4, 126.2, 126.6, 129.6, 142.2, 142.8, 148.6,
160.3; IR (neat) 1006, 1209, 1242, 1366, 1456, 1495, 1557, 1625, 2852, 2922, 3057
cm-1; HRMS found: m/z 286.1106. Calcd for 286.1103.
Ethyl 4-[2-(Methyl(phenyl)amino)-thiazol-5-yl] benzoate
(14a): 1H NMR (500 MHz, CDCl3) δ 1.38 (t, J = 7.0 Hz, 3H),
3.57 (s, 3H), 4.36 (q, J = 7.2 Hz, 2H), 7.29-7.33 (m, 1H), 7.39-7.48 (m, 6H), 7.57 (s,
1H), 7.95 (d, J = 8.8 Hz, 2H); 13C NMR (125 MHz, CDCl3) δ 14.5, 40.3, 61.0, 124.8,
125.4, 126.5, 127.1, 128.3, 130.1, 130.3, 136.9, 137.0, 146.2, 166.4, 170.5; IR (neat)
1023, 1107, 1183, 1275, 1366, 1404, 1452, 1564, 1605, 1709, 2927, 3035, 3056 cm-1;
HRMS found: m/z 338.1089. Calcd for 338.1092.
Ethyl 4-(2-Diphenylaminothiazol-5-yl)-benzoate (14b): 1H NMR (500 MHz, CDCl3) δ 1.39 (t, J = 7.0 Hz, 3H), 4.37
(q, J = 7.3 Hz, 2H), 7.26-7.30 (m, 2H), 7.38-7.46 (m, 10H),
7.62 (s, 1H), 7.98 (d, J = 8.5 Hz, 2H); 13C NMR (125 MHz, CDCl3) δ 14.5, 61.2, 125.2,
126.2, 127.3, 128.2, 129.3, 130.2, 130.4, 134.5, 135.8, 144.4, 166.2, 169.2; IR (neat)
1021, 1107, 1184, 1274, 1366, 1409, 1446, 1477, 1605, 1711, 2927, 2978, 3062 cm-1;
HRMS found: m/z 400.1245. Calcd for 400.1250.
N
ONPh2
N
Sp-EtO2CC6H4 NPh2
N
Sp-EtO2CC6H4 N
Me
Ph
N
SN
Me
PhMe
Me
S3
Other coupling products 3a1), 3b2), 7a3), 7d4), 7e3) and 9a1) are known in the literature.
References
1 Hooper, M. W.; Utsunomiya, M.; Hartwig, J. F. J. Org. Chem. 2003, 68, 2861-2873.
2 Muthusamy, S.; Pharmasivam, R.; Ramakrishnan, V. T. J. Heterocyclic. Chem.
1991, 28, 759-763.
3 Khalaf, A. I.; Alvarez, R. G.; Suckling, C. J.; Waigh, R. D. Tetrahedron 2000, 56,
8567-8571.
4 Hwang, J. Y.; Gong, Y.-D. J. Comb. Chem., 2006, 8, 297-303.
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