J. Yuan et al.
2,6-diethyl-4-naphthylaniline (0.41 g, 74% yield). 1H NMR (400 MHz,
CDCl3): δ 8.08 (d, J = 7.8 Hz, 1H, naphthyl), 7.91 (d, J = 8.0 Hz, 1H,
naphthyl), 7.83 (d, J = 6.8 Hz, 1H, naphthyl), 7.43–7.55 (m, 4H,
naphthyl), 7.18 (s, 2H, aniline), 3.72(br, s, 2H, –NH2), 2.64 (q, J =
7.1 Hz, 4H, –CH2CH3), 1.34 (t, J = 7.1 Hz, 6H, –CH2CH3). 13CNMR
(100 MHz, CDCl3): δ 140.42 (aniline carbon connected with
NH2), 133.51 (naphthyl carbon connected with aniline), 130.19
(naphthyl carbon), 128.32 (naphthyl carbon), 128.14 (naphthyl
carbon), 128.05 (naphthyl carbon), 127.75 (naphthyl carbon),
127.31 (aniline carbon), 126.99 (naphthyl carbon), 126.41
(naphthyl carbon), 126.36 (naphthyl carbon), 126.00 (naphthyl
carbon), 125.74 (aniline carbon connected with naphthyl),
125.21 (aniline carbon connected with ethyl), 23.92 (–CH2CH3),
12.66 (–CH2CH3). Anal. Calcd for C20H21BrN: C, 87.23; H, 7.69;
Experimental
General Considerations and Materials
All manipulations involving air and/or moisture-sensitive com-
pounds were carried out with standard Schlenk techniques under
nitrogen. Methylene chloride and o-dichlorobenzene were pre-
dried with 4 Å molecular sieves and distilled from CaH2 under
dry nitrogen. Toluene, diethyl ether and 1,2-dimethoxyethane
(DME) were distilled from sodium/benzophenone under an N2
atmosphere. Anhydrous NiBr2 (99%), 1-naphthylboronic acid
(97%), trifluoromethanesulfonic acid (99%), Pd(OAc)2 and
diethylaluminum chloride (DEAC, 0.9 M solution in toluene) were
obtained from Acros. 2,3-Butanedione (98%), 2,6-diethylaniline
(98%), 4-fluoroaniline (98%) and 4-fluoro-2-methylaniline (98%)
were purchased from Alfa Aesar and used without further purifica-
tion. [NiBr2(DME)] was synthesized according to the literature.[26]
NMR spectra were recorded at 400 (1H) and 100 (13C) MHz,
respectively, on a Varian Mercury plus-400 instrument with TMS
as internal standard. FT-IR spectra were recorded on a Digilab
Merlin FTS 3000 FT-IR spectrophotometer in KBr pellets. The
molecular weights and molecular weight distributions (Mw/Mn)
of the polymers were determined by gel permeation chromatog-
raphy–size exclusion chromatography (GPC-SEC) via a Waters
Alliance GPCV2000 chromatograph and polystyrene was used
as the standard, using 1,2,4-trichlorobenzene as eluent, at a flow
rate of 1.0 ml minꢀ1 and operated at 140°C. The elemental
content of samples was determined by elemental analyzer
(Vaiio-EL106, Germany).
N, 5.09. Found: C, 87.11; H, 7.81; N, 5.27. FT-IR (KBr) 3369 cmꢀ1
,
3441 cmꢀ1 (–NH2).
Synthesis of 4-fluoro-2-methyl-6-sec-phenethylaniline 1b
CF3SO3H (0.06 g, 0.40 mmol), 4-fluoro-2-methylaniline (0.25 g,
2.00 mmol), styrene (0.42 g, 4.00 mmol) and xylene (2 ml) were
placed in a 10 ml Schlenk flask and stirred at 160°C for 8 h.
Volatile materials were removed and the residue was purified
by chromatography on silica gel with petroleum ether–ethyl ace-
tate (v/v, 10:1) to give 4-fluoro-2-methyl-6-sec-phenethylaniline
1
as light-yellow oil (0.32 g, 70% yield). H NMR (400 MHz, CDCl3):
δ 7.12–7.23 (m, 5H, C6H5CHCH3), 6.83 (s, 2H, aniline ring), 6.64
(s, 2H, aniline ring), 3.96 (q, J = 7.1 Hz, 1H, C6H5CHCH3), 3.13
(br, s, 2H, –NH2), 2.00 (s, 3H, –CH3 of aniline), 1.50 (d, J = 7.1 Hz,
3H, C6H5CHCH3). 13C NMR (100 MHz, CDCl3): δ 157.02 (aniline
carbon connected with fluorine), 154.68 (phenethyl ring carbon
connected with ethyl), 144.88 (aniline carbon connected with
NH2), 138.10 (aniline carbon connected with methyl), 130.51
(phenyl carbon), 128.62 (phenyl carbon), 127.35 (phenyl carbon),
126.34 (aniline carbon connected with phenethyl), 114.71 (aniline
carbon near methyl), 111.30 (aniline carbon near F), 40.26
(C6H5CHCH3), 21.90 (C6H5CHCH3), 17.53 (–CH3 of aniline). Anal.
Calcd for C15H16FN: C, 78.57; H, 7.03; N, 6.11. Found: C, 78.62; H,
6.89; N, 5.97. FT-IR (KBr) 3381 cmꢀ1, 3443 cmꢀ1 (–NH2).
Synthesis of 4-bromo-2,6-diethylaniline
Acetic acid (2 ml) was added to a stirred solution of 2,6-
diethylaniline (0.75 g, 5 mmol) in CH2Cl2. The solution was stirred
for 30 min. After the solution was cooled to 5°C in an ice bath, Br2
(0.96 g, 6.0 mmol) in 5 ml CH2Cl2 was slowly added to the stirred
solution. The mixture was stirred for 6 h and neutralized by 10%
saturated aqueous sodium hydroxide solution. The mixture was
extracted three times with 50 ml petroleum ether. The combined
organic phase was dried over MgSO4, filtered and the solvent re-
moved. The residue was purified by chromatography on silica gel
with petroleum ether–ethyl acetate (v/v = 10:1) to give 4-bromo-
2,6-diethylaniline (0.94 g, 83% yield). 1H NMR (400 MHz, CDCl3): δ
7.06 (s, 2H, aniline ring), 3.59 (br, s, 2H, –NH2), 2.48 (q, J = 7.1 Hz,
4H, –CH2CH3), 1.24 (t, J = 7.1 Hz, 6H, –CH2CH3). 13C NMR (100 MHz,
CDCl3): δ 141.77 (aniline carbon connected with NH2), 129.79
(aniline carbon near Br), 128.61 (aniline carbon connected
with ethyl), 110.43 (aniline carbon connected with Br), 24.25
(–CH2CH3), 12.91 (–CH2CH3). 7.06 (s, 2H, aniline ring), 3.59 (br, s,
2H, –NH2), 2.48 (q, J = 7.1 Hz, 4H, –CH2CH3), 1.24 (t, J = 7.1 Hz, 6H,
–CH2CH3). Anal. Calcd for C10H14BrN: C, 52.65; H, 6.19; N, 6.14.
Found: C, 52.37; H, 6.37; N, 6.29. FT-IR (KBr) 3361 cmꢀ1, 3438
cmꢀ1 (–NH2).
Synthesis of 4-fluoro-6-sec-phenethylaniline 1c or 1d
Using the same procedure as for the synthesis of 1b, 1c/1d was
obtained as a light-yellow oil (0.52 g, 60% yield). 1H NMR
(400 MHz, CDCl3): δ 7.15–7.27 (m, 5H, C6H5CHCH3), 7.01 (s, 1H,
aniline ring), 6.77 (d, J = 8.4 Hz, 1H, aniline ring), 6.51 (d, J = 8.6
Hz, 1H, aniline ring), 4.02 (q, J = 7.1 Hz, 1H, C6H5CHCH3), 3.24
(br, s, 2H, –NH2), 1.56 (d, J = 7.1 Hz, 3H, C6H5CHCH3). 13C NMR
(100 MHz, CDCl3): δ 157.74 (aniline carbon connected with F),
144.78 (phenethyl ring carbon connected with ethyl), 140.15
(aniline carbon connected with NH2), 128.72 (phenyl carbon),
127.28 (phenyl carbon), 126.46 (phenyl carbon), 116.73 (aniline
carbon connected with phenethyl), 113.73 (aniline carbon),
113.40 (aniline carbon), 113.18 (aniline carbon), 40.07 (C6H5CHCH3),
21.65 (C6H5CHCH3). Anal. Calcd for C14H14FN: C, 78.11; H, 6.56;
Synthesis of 2,6-diethyl-4-naphthylaniline 1a
N, 6.51. Found: C, 77.94; H, 6.75; N, 6.82. FT-IR (KBr) 3374 cmꢀ1
,
3439 cmꢀ1 (–NH2).
Pd(OAc)2 (0.01 g, 0.04 mmol), 4-bromo-2,6-diethylaniline (0.46 g,
2.00 mmol), K2CO3 (0.55 g, 4.00 mmol) and 1-naphthyl boric
acid (0.38 g, 2.20 mmol) were placed in a 50 ml flask and stirred
at 25°C for 24 h, in the presence of 10 ml PEG-400. The mixture
was extracted three times with 15 ml diethyl ether. The com-
bined organic phase was dried over MgSO4, filtered and the sol-
vent was removed. The residue was purified by chromatography
on silica gel with petroleum ether–ethyl acetate (v/v, 30:1) to give
Synthesis of bis[N,N′-(2,6-diethyl-4-naphthylphenyl)imino]-1,2-
dimethylethane 2a
Formic acid (0.5 ml) was added to a stirred solution of 2,3-
butanedione (0.09 g, 1.00 mmol) and 2,6-diethyl-4-naphthylaniline
(0.61 g, 2.2 mmol) in ethanol (20 ml). The mixture was refluxed for
48 h, then cooled and the precipitate was separated by filtration.
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Appl. Organometal. Chem. (2014)