Beilstein J. Org. Chem. 2016, 12, 2443–2449.
6a: colorless oil. 1H NMR (CDCl3) δ 2.31 (s, 3H, ArCH3), 4.95 benzyltrimethylammonium bromides (50 mmol), dissolved in
(s, 2H, ArCH2), 6.96–6.98 (m, 1H, ArH), 6.99–7.24 (m, 1H, 5 mL water, was added dropwise in 30 min. The inhibitor
ArH), 7.26–7.37 (m, 1H, ArH); anal. calcd for C8H8BrCl (0.15 mmol) was then added to the solution and the mixture was
(219.51): C, 43.77; H, 3.67; Cl, 16.15; found: C, 43.68; H, 3.72; heated under reflux for 4 h. After all water had been separated,
Cl, 16.06.
a pale yellow solid polymer began to precipitate. When the
evolution of Me3N was finished, the reaction system was heated
8a: mp 53–55 °C; 1H NMR (CDCl3) δ 2.31 (s, 3H, ArCH3), and stirred for another 1 h. The mixture was cooled and the
4.93 (s, 2H, ArCH2), 7.02–7.54 (m, 3H, ArH); anal. calcd for solid was filtrated and washed with toluene (5 mL × 3). The
C8H8BrCl (219.51): C, 43.77; H, 3.67; Cl, 16.15; found: C, filtrates were combined and evaporated under vacuum to give a
43.68; H, 3.72; Cl, 16.06.
solid product which was further washed with hexane
(5 mL × 3).
10a: mp 72–74 °C; 1H NMR (CDCl3) δ 2.41 (s, 3H, ArCH3),
4.95 (s, 2H, ArCH2), 6.96–7.37 (m, 3H, ArH); anal. calcd for 16: white solid, mp >280 °C (dec); 1H NMR (CDCl3) δ 2.91
C8H8BrNO2 (230.06): C, 41.77; H, 3.51; N, 6.09; found: C, (m, 2H, ArCH2), 3.26 (m, 2H, ArCH2), 6.95 (s, 2H, ArH);
41.68; H, 3.57; N, 6.12.
13C NMR (CDCl3) δ 30.8, 77.0, 131.8, 133.9, 138.6; anal. calcd
for C16H12Cl4 (346.07): C, 55.53; H, 3.50; Cl, 40.97; found: C,
55.47; H, 3.62; Cl, 40.89.
Typical reaction procedure for the prepara-
tion of substituted (4-methylbenzyl)trimethyl-
ammonium bromides
17: white solid, mp 281–283 °C; 1H NMR (CDCl3) δ 3.09 (s,
8H, ArCH2), 6.50 (s, 8H, ArH); anal. calcd for C16H16
(208.30): C, 92.26; H, 7.74; found: C, 92.15; H, 7.82.
Substituted 4-methylbenzyl bromide (5.0 mmol) was added to
50.0 mL Et2O solution in a 100 mL three-necked flask. The
mixture was cooled at 0 °C and was stirred at 300 rpm. Me3N
was generated by heating an aqueous Me3N solution (40% w/w,
15 mL) and passed into the flask for 4 h. The product was pre-
cipitated as a white solid. Then the mixture was stirred at room
temperature overnight and the quaternary ammonium salt was
obtained on a Büchner funnel and dried in a vacuum oven at
80 °C for 24 h.
18: white solid, mp 163–165 °C; 1H NMR (CDCl3) δ 2.85–2.97
(m, 4H, ArCH2), 3.03–3.37 (m, 4H, ArCH2), 6.92–7.54 (m, 6H,
ArH). anal. calcd for C16H14Cl2 (277.19): C, 69.33; H, 5.09; Cl,
25.58; found: C, 69.27; H, 5.05; Cl, 25.65.
19: white solid, mp 238–240 °C; 1H NMR (CDCl3) δ 2.86–3.12
(m, 4H, ArCH2), 3.15–3.34 (4H, m, ArCH2), 6.43–7.15 (m, 6H,
11: highly hygroscopic solid. IR (KBr) ν/cm−1: 3004, 1635, ArH); anal. calcd for C16H14Br2 (366.10): C, 52.49; H, 3.85;
1617, 1477, 1375, 1190, 980. found: C, 52.38; H, 3.82.
12: highly hygroscopic solid. IR (KBr) v/cm−1: 2989, 1521, 20: 1H NMR (CDCl3) δ 2.81–3.07 (m, 4H, ArCH2), 3.27–3.35
1483, 1382, 1125, 910, 805, 722.
(m, 4H, ArCH2), 7.25–8.23 (m, 6H, ArH); anal. calcd for
C16H14N2O4 (298.30): C, 64.42; H, 4.73; N, 9.39; found: C,
13: highly hygroscopic solid. IR (KBr) v/cm−1: 2968, 2935, 64.32; H, 4.75; N, 9.45.
1632, 1452, 1371, 1154, 725, 672.
Supporting Information
14: highly hygroscopic solid. IR (KBr) v/cm−1: 3009, 2946,
1642, 1458, 1381, 1205, 653.
Supporting Information File 1
Copies of MS, 1H and 13C NMR spectra of the synthesized
compounds.
15: highly hygroscopic solid. IR (KBr) v/cm−1: 2979, 1621,
1550, 1508, 1472, 1376, 1345, 1135, 663.
Typical reaction procedure for the synthesis
of substituted tetrachloro[2.2]paracyclo-
phanes
Acknowledgements
In a 100 mL three-necked flask equipped with a stirrer and a
Dean–Stark water separator attached to a reflux condenser was
placed 15 mL aqueous sodium hydroxide solution (40% w/w)
and 45 mL toluene. With vigorous stirring, a solution of
This work was financially supported by the National Natural
Science Foundation of China (No. 21276050 and 21406034),
Fundamental Research Funds for the central Universities (No.
3207045414).
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