The Journal of Organic Chemistry
Note
LRMS (APCI) m/z (relative intensity, %) 311.02 (14), 310.02
[(M + H)+, 96], 309.02 (14), 308.02 [(M + H)+, 100].
1-(2-Bromo-4-chloro)-3-methyl-3-phenyltriazene (1d).
1H NMR (500 MHz, CDCl3) δ 7.61 (dd, J = 8.3, 2.8 Hz, 1H), 7.48
(dd, J = 8.3, 5.8 Hz, 1H), 7.45 (d, J = 8.5 Hz, 2H), 7.39 (dd, J = 8.5,
7.2 Hz, 2H), 7.15 (t, J = 7.2 Hz, 1H), 3.70 (s, 3H); 13C NMR (125
MHz, CDCl3) δ 161.7, 159.7, 146.2, 146.2, 144.7, 129.2, 125.8, 125.6,
124.1, 118.3, 118.3, 117.3, 116.0, 115.8, 96.9, 96.8, 33.5; LRMS
(APCI) m/z (relative intensity, %) 357.00 (13), 356.01 [(M + H)+,
100], 328.00 (12). Anal. Calcd for C13H11FIN3: C, 43.96; H, 3.12; N,
11.83. Found: C, 44.01; H, 3.13; N, 11.88.
An orange solid [1.04 g, 3.19 mmol, 94% from 2-bromo-4-chloroani-
1-(2-Iodo-4-chrolo)-3-methyl-3-phenyltriazene (1i).
line12 (700 mg, 3.39 mmol)]; mp = 59−60 °C from CH2Cl2/hexane
5
1
(lit. 76−77 °C); H NMR (400 MHz, CDCl3) δ 7.64 (d, J = 2.1 Hz,
1H), 7.51 (d, J = 8.8 Hz, 1H), 7.47−7.44 (m, 2H), 7.43−7.38 (m, 2H),
7.26 (dd, J = 8.8, 2.1 Hz, 2H), 7.19−7.15 (m, 1H), 3.71 (s, 3H); 13C
NMR (100 MHz, CDCl3) δ 146.4, 144.7, 132.7, 132.0, 129.2, 128.1,
124.3 121.0, 119.5, 117.5, 33.4; LRMS (ESI) m/z (relative intensity, %)
327.99 [(M + H)+, 24], 325.99 [(M + H)+, 100], 323.99 [(M + H)+, 76].
1-(2-Bromo)-3-methyl-3-phenyltriazene (1e).
A red solid [999 mg, 2.69 mmol, 90% from 4-chloro-2-iodoaniline16
(760 mg, 3.00 mmol)]; mp = 73−74 °C from CH2Cl2/hexane; H
1
NMR (400 MHz, CDCl3) δ 7.87 (d, J = 2.7 Hz, 1H), 7.45−7.42 (m,
3H), 7.41−7.37 (dd, J = 9.3 Hz, 2H), 7.29 (dd, J = 10.8, 2.7 Hz, 1H),
7.16 (t, J = 9.3 Hz, 1H), 3.70 (s, 3H); 13C NMR (100 MHz, CDCl3) δ
148.3, 144.6, 138.4, 132.2, 129.2, 129.0, 124.3, 118.4, 117.5, 97.41, 33.7;
LRMS (APCI) m/z (relative intensity, %) 373.97 (31), 372.98 (13),
371.98 [(M + H)+, 100], 343.97 (12). Anal. Calcd for C13H11ClIN3: C,
42.02; H, 2.98; Cl, 9.54; N, 11.31. Found: C, 42.29; H, 3.00; Cl, 9.81;
N, 11.36.
A red oil, 92% [3.12 g, 10.8 mmol, 92% from commercially available
1
2-bromoaniline (2.0 g, 11.6 mmol)]; H NMR (400 MHz, CDCl3) δ
7.64 (dd, 1H, J = 8.4, 1.4 Hz), 7.57 (dd, 1H, J = 8.4, 1.4 Hz), 7.49 (d,
2H, J = 8.7 Hz), 7.41 (dd, 2H, J = 8.7, 7.5 Hz), 7.31 (ddd, 1H, J = 8.4,
7.2, 1.4 Hz), 7.17 (t, 1H, J = 7.5 Hz), 7.09 (ddd, 1H, J = 8.4, 7.2, 1.4
Hz), 3.73 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 147.4, 144.8, 133.2,
129.2, 127.8, 127.5, 124.0, 120.7, 119.0, 117.3, 33.1; LRMS (APCI)
m/z (relative intensity, %) 293.03 (14), 292.03 [(M + H)+, 98],
291.03 (14), 290.03 [(M + H)+, 100].
1-(2-Iodophenyl)-3-methyl-3-phenyltriazene (1j).
An orange oil [968 mg, 2.87 mmol, 96% from commercially available
1
1-(2-Iodo 4-ethoxycarbonyl)-3-methyl-3-phenyltriazene (1f).
2-iodoaniline (657 mg, 3.00 mmol)]; H NMR (500 MHz, CDCl3) δ
7.90 (d, J = 7.5 Hz, 1H), 7.52 (dd, J = 7.5, 1.0 Hz, 1H), 7.46 (d, J = 8.0
Hz, 2H), 7.39 (dd, J = 8.3, 7.5 Hz, 2H), 7.33 (ddd, J = 7.5, 7.5, 1.0 Hz,
1H), 7.15 (t, J = 7.5 Hz, 1H), 6.92 (dd, J = 7.5, 7.5 Hz,1H), 3.34 (s,
3H); 13C NMR (125 MHz, CDCl3) δ 149.6, 144.8, 139.3, 129.2, 128.8,
127.9, 124.0, 118.1, 117.3, 97.5, 33.4. Anal. Calcd for C13H12IN3: C,
46.31; H, 3.59; N, 12.46. Found: C, 46.52; H, 3.57; N, 12.57.
Preparation of Sulfur-Modified Au-Supported Pd Material
(SAPd). SAPd was prepared according to the literature.8d The Au
(100 mesh, 14 × 12 mm2, 100.7 mg) was placed in the piranha
solution for 5 min and then washed first with H2O (3.0 mL × 10)
and then with EtOH (3.0 mL × 6). The Au mesh was placed in
a round-bottom flask and dried for 10 min under reduced pressure
(ca. 6 mmHg). The sulfur-modified Au mesh was placed in a solution
of Pd(OAc)2 (5.3 mg, 0.023 mmol) in xylene (3.0 mL) and stirred at
100 °C for 12 h. Then it was rinsed with xylene (3.0 mL × 50), and
after vacuum drying, it was placed in xylene (3.0 mL) and heated at
135 °C for 12 h. Finally, it was rinsed with xylene (3.0 mL × 50) and
dried under vacuum for 10 min to give sulfur-mocdified Au-supported
Pd material (SAPd, 100.8 mg), and only this SAPd was used
throughout this research.
A yellow solid [586 mg, 1.43 mmol, 48% from ethyl 4-amino-3-
iodobenzoate13 (831 mg, 3.00 mmol)]; mp = 124−125 °C from CH2Cl2/
1
hexane; H NMR (500 MHz, CDCl3) δ 8.57 (d, J = 1.3 Hz, 1H), 8.00
(dd, J = 7.2, 1.3 Hz, 1H), 7.54 (d, J = 7.2 Hz, 1H), 7.49 (d, J = 7.5 Hz,
2H), 7.42 (t, J = 7.5 Hz, 2H), 7.20 (t, J = 7.5 Hz, 1H), 4.37 (q, J = 7.3 Hz,
2H), 3.76 (s, 3H), 1.40 (t, J = 7.3 Hz, 3H); 13C NMR (125 MHz, CDCl3)
δ 165.1, 152.9, 144.5, 140.7, 130.2, 129.3, 129.3, 124.7, 117.8, 117.4, 96.7,
61.2, 34.0, 14.3; LRMS (APCI) m/z (relative intensity, %) 412.03 (16),
410.03 [(M + H)+, 100], 382.03 (12). Anal. Calcd for C16H16IN3O2: C,
46.96; H, 3.94; N, 10.27. Found: C, 46.80; H, 3.90; N, 10.21.
1-(2-Iodo-4-cyano)-3-methyl-3-phenyltriazene (1g).
General Procedure for the Synthesis of Benzotriazoles with
Pd(OAc)2. According to Ren’s procedure,5 1a (72.5 mg, 0.2 mmol,
1.0 equiv), Pd(OAc)2 (2.2 mg, 10 μmol, 5 mol %), dppp (8.2 mg,
20 μmol, 10 mol %), and KOAc (23.6 mg, 0.24 mmol, 1.2 equiv) were
dissolved in 800 μL of dried DMF. The reaction mixture was stirred at
110 °C. After being heated, the reaction mixture was cooled to rt and
2.0 mL of H2O was added. The resulting mixture was extracted with
AcOEt. The organic layer was washed with brine and dried over
Na2SO4 and concentrated under reduced pressure. The crude product
was purified by silica gel chromatography (hexane/AcOEt = 9/1−3/1).
General Procedure for the Synthesis of Benzotriazoles with
SAPd. In the presence of SAPd, to a solution of 1 (0.16 mmol) in
1.5 mL of dried DMF were added and stirred at 120 °C KOAc
(78.5 mg, 0.8 mmol, 5.0 equiv) and PhI(OAc)2 (61.8 mg, 0.192 mmol,
1.2 equiv). After 30 min, SAPd was removed and the reaction mixture
was stirred at 120 °C. After completion of the reaction, the reaction
mixture was cooled to rt and 2.0 mL of H2O was added. The resulting
mixture was extracted with AcOEt. The organic layer was washed with
An orange solid [1.97 g, 5.43 mmol, 91% from 4-amino-3-iodo-
benzonitrile14 (1.46 g, 6.00 mmol)]; mp = 165−166 °C from CH2Cl2/
hexane; 1H NMR (500 MHz, CDCl3) δ 8.17 (d, J = 1.0 Hz, 1H), 7.61−
7.57 (m, 2H), 7.49 (d, J = 8.8 Hz, 2H), 7.44 (dd, J = 8.8, 7.5 Hz, 2H),
7.24 (t, J = 7.5 Hz, 1H), 3.79 (s, 3H); 13C NMR (125 MHz, CDCl3) δ
153.0, 144.3, 142.8, 132.5, 129.4, 125.3, 118.0, 118.0, 117.7, 110.6, 96.8,
34.5; LRMS (APCI) m/z (relative intensity, %) 364.01 (14), 363.01
[(M + H)+, 100], 335.00 (18). Anal. Calcd for C14H11IN4: C, 46.43; H,
3.06; N, 15.47. Found: C, 46.48; H, 3.09; N, 15.51.
1-(2-Iodo-4-fluoro)-3-methyl-3-phenyltriazene (1h).
An orange solid [1.01 g, 2.86 mmol, 95% from 4-fluoro-2-iodoaniline15
(711 mg, 3.00 mmol)]; mp = 61−62 °C from CH2Cl2/hexane;
D
dx.doi.org/10.1021/jo5009838 | J. Org. Chem. XXXX, XXX, XXX−XXX