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OH
OH
OH
OH
glycol, and excess hydrazine hydrate (85%) was heated and
was refluxed for 2 h. Then the reaction mixture was cooled
to room temperature and was added to 1 mol KOH pellet.
Water and additional hydrazine hydrate were distilled off
until the reaction temperature increased to 195–200 °C. At
this temperature the mixture was refluxed for 5 h. After the
completion of the reaction, the mixture was diluted with
water and extracted with ethyl ether. The water layer
product was added to concentrated hydrochloric acid until
the pH value was 5–6 and extracted with ethyl ether several
times. The organic layer was separated, and washed with
water. After removal of ethyl ether by distillation, the
residue was dried and purified by recrystallization from
petroleum ether to give colorless crystal 4c: yield 86%;
m.p. 68 °C; 1H NMR (400 MHz, CDCl3) d 7.04–7.02
(d, 2H, ArH), 6.76–6.72(d, 2H, ArH), 4.97(s, 1H, OH),
2.54–2.50(t, 2H, CH2), 1.59–1.52(t, 2H, CH2),
1.25–1.29(m, 18H, 9CH2), 0.86–0.89(t, 3H, CH3). The
other alkylphenol products were obtained from the same
procedures. n-octylphenol 4a: yield 83%; m.p. 39–40 °C;
1H NMR(400 MHz, CDCl3) d 7.03–7.01(d, 2H, ArH),
6.76–6.72(d, 2H, ArH), 5.36(s, 1H, OH), 2.53–2.49(t, 2H,
CH2), 1.57–1.52(t, 2H, CH2), 1.29–1.26(m, 10H, CH2),
0.89–0.86(t, 3H, CH3). n-decylphenol 4b: yield 80%; m.p.
CH2OH
HO
CnH2n+1
HCHO
catalyst
H2O
CnH2n+1
CnH2n+1
CnH2n+1
CnH2n+1
4
5
a, b, c, d, e, f: n = 8, 10, 12, 14, 16, 9
Scheme 2 Synthesis route of bis(2-hydroxy-5-alkylphenyl)methanes
removed by vacuum distillation at approximately 670 Pa.
The reaction mixture was continuously monitored by thin
layer chromatography (TLC). After the completion of the
reaction, the products were washed with water, dried and
purified by column chromatography and confirmed by
NMR and FTIR. The products were colorless crystals:
a. Bis(2-hydroxy-5-n-octylphenyl) methane. Yield 67%;
1
m.p. 44–45 °C; H NMR(400 MHz, CDCl3) d 7.40(s, 1H,
OH), 7.07(d, 2H, ArH), 6.88–6.85(d, 2H, ArH),
6.73–6.71(d, 2H, ArH), 3.86(s, 2H, CH2), 2.51–2.48(t, 2H,
CH2), 1.56–1.51(t, 2H, CH2), 1.30–1.26(m, 10H, 5CH2),
0.90–0.86(t, 3H, CH3); 13C NMR(400 MHz, CDCl3) d
150.29, 136.07, 130.66, 129.09, 126.89, 115.80, 35.19,
32.00, 31.84, 31.32, 29.60, 29.43, 29.40, 22.77, 14.19.
FTIR (KBr) m 3,250.95 cm-1(OH stretching); Anal. Calc.
for C29H44O2: C, 82.02; H, 10.44; O, 7.54. Found: C,
81.93; H, 10.45; O, 7.56. b. Bis(2-hydroxy-5-n-decyl-
phenyl) methane. Yield 61%; m.p. 54–55 °C; 1H
NMR(400 MHz, CDCl3) d 7.82(s, 1H, OH), 7.07(d, 2H,
ArH), 6.87–6.84(d, 2H, ArH), 6.75–6.71(d, 2H, ArH),
3.87(s, 2H, CH2), 2.51–2.48(t, 2H, CH2), 1.56–1.53(t, 2H,
CH2), 1.30–1.26(m, 14H, 5CH2), 0.90–0.86(t, 3H, CH3);
13C NMR(400 MHz, CDCl3) d 150.30, 135.97, 130.65,
127.78, 126.85, 115.77, 35.17, 31.99, 31.82, 31.28, 29.72,
29.62, 29.42, 22.76, 14.18; FTIR(KBr) m 3,277.63 cm-1
(OH stretching); Anal. Calc. for C33H52O2: C, 82.44; H,
10.90; O, 6.66. Found: C, 82.35; H, 10.10; O, 6.67.
c. Bis(2-hydroxy-5-n-dodecylphenyl) methane. Yield
1
52–53 °C; H NMR(400 MHz, CDCl3) d 7.03–7.01(d,2H,
ArH), 6.75–6.73(d,2H, ArH), 5.24(s,1H, OH), 2.53–2.49
(t, 2H, CH2), 1.57–1.54(t, 2H, CH2), 1.29–1.25(m, 14H,
CH2), 0.89–0.86(t, 3H, CH3). n-tetradecylphenol 4d: yield
82%; m.p. 68–69 °C; 1H NMR(400 MHz, CDCl3) d
7.05–7.02(d, 2H, ArH), 6.76–6.72(d, 2H, ArH), 4.64(s, 1H,
OH), 2.54–2.50(t, 2H, CH2), 1.58–1.54(t, 2H, CH2),
1.29–1.25(m, 22H, CH2), 0.90–0.86(t, 3H, CH3). n-hex-
adecylphenol 4e: yield 80%; m.p. 78–79 °C; 1H
NMR(400 MHz, CDCl3)
d 7.05–7.02(d, 2H, ArH),
6.75–6.73(d, 2H, ArH), 4.67(s, 1H, OH), 2.54–2.50(t, 2H,
CH2), 1.58–1.54(t, 2H, CH2), 1.29–1.25(m, 26H, CH2),
0.90–0.86(t, 3H, CH3).
1
62%; m.p. 71–72 °C; H NMR(400 MHz, CDCl3) d 6.96
(s, 1H, OH), 7.09–7.06(d, 2H, ArH), 6.89–6.81(d, 2H,
ArH), 6.77–6.70(d, 2H, ArH), 3.85(s, 2H, CH2), 2.52–2.45
(t, 2H, CH2), 1.55–1.53(t, 2H, CH2), 1.26–1.25(m, 10H,
5CH2), 0.89–0.86(t, 3H, CH3); 13C NMR(400 MHz,
CDCl3) d 149.00, 134.85, 129.44, 126.80, 125.73, 114.63,
34.00, 30.84, 30.65, 30.16, 28.63, 28.48, 28.29, 21.60,
13.00; FTIR(KBr) m 3,238.12 cm-1(OH stretching); Anal.
Calc. for C37H60O2: C, 82.87; H, 11.26; O, 5.96. Found: C,
82.79; H, 11.29; O, 5.94. d. Bis(2-hydroxy-5-n-tetrade-
cylphenyl) methane. Yield 68%; m.p. 75–76 °C; 1H
NMR(400 MHz, CDCl3) d 6.52(s, 1H, OH), 7.07–7.06
(d, 2H, ArH), 6.91–6.88(d, 2H, ArH), 6.73–6.71(d, 2H,
ArH), 3.87(s, 2H, CH2), 2.52–2.48(t, 2H, CH2), 1.56–
1.51(t, 2H, CH2), 1.29–1.25(m, 18H, 5CH2), 0.90–0.86
(t, 3H, CH3); 13C NMR(400 MHz, CDCl3) d 150.43,
Synthesis of Bis(2-hydroxy-5-alkylphenyl)methanes
The synthesis route of bis(2-hydroxy-5-alkylphenyl)meth-
anes is shown in Scheme 2.
Bis(2-hydroxy-5-n-alkylphenyl)methanes (5a–5e)
A 0.1-mol sample of n-alkylphenol was put into a flask and
heated to 50 °C with stirring and introduction of a nitrogen
stream. To it was then added a solution of oxalic acid
dihydrate in distilled water, sodium dodecylbenzenesulfo-
nate and, finally, portionwise 0.05 mol paraformaldehyde
at such a rate that the temperature in the flask was
85–95 °C. The resulting mixture was slowly heated to
125–135 °C and the water contained in the mixture was
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