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Ray et al.
Friedel–Crafts Reaction of (4-Methoxyphenyl)-naphth-1-yl Carbinol (1)
with o-Cresol in Presence of AlCl3
To a stirred solution of (4-methoxyphenyl)-naphth-1-yl-carbinol (5 g,
18.9mmol) and o-cresol (2.4 mL, 23.26 mmol) in a mixture of dry benzene
and pentane (50 mL, 1 : 1), AlCl3 (2.5g, 18.7mmol) was added gradually.
After addition, stirring was continued for 1–2 hr at 0–48C. The reaction mixture
was decomposed in crushed ice with conc. HCl (0.5mL) and extracted with
ethyl acetate. The organic layer was washed successively with water, dried
over sodium sulfate, and concentrated to give oil which was chromatographed
over silica-gel using increasing amounts of ethyl acetate in hexane (hexane to
2% ethyl acetate in hexane) as eluant, when following products (4–8) were
obtained: (4-methoxyphenyl)-(4-hydroxy-3methyl phenyl)-naphth-1-yl-methane
(6, 55%), (4-methoxyphenyl)-(2-hydroxyphenyl)-naphth-1-yl-methane (7, 5%),
bis-(3-methyl-4-hydroxyphenyl)-naphth-1-yl-methane (8, 15%), bis-(4-methoxy-
phenyl)-naphth-1-yl-methane (4, 10%), (4-methoxyphenyl)-naphth-1-yl methane
(5, 8%).
bis-(4-Methoxyphenyl)-naphth-1-yl-methane (4). IR (neat, cm21): 1560,
1
1500 (ArH), 1245 (OMe). H NMR (d, CDCl3): 3.74 (s, 6H, 2 Â OMe), 6.16
(s, 1H, CH), 6.81 (dd, 4H, ortho to OMe), 7.1 (dd, 4H, meta to OMe), 6.93
(d, 1H, naphth), 7.31–7.43 (m, 3H, naphth), 7.71 (d, 1H, naphth), 7.83 (d, 1H,
naphth), 7.93 (d, 1H, naphth). 13C NMR, d: 158, 141, 136, 133, 130.5, 130, 128,
127–126 (4C) 124.8, 116, 55.5, 55.5. MS: m/z 354. Anal. Calcd for C25H22O2:
C, 84.74%; H, 6.21%. Found: C, 84.23%; H, 6.03%.
(4-Methoxyphenyl)-naphth-1-yl-methane(5). M.p.:99–1018C.IR(KBr,
cm21): 1600, 1500, 1450 (ArH). 1H NMR (d, CDC13): 3.74 (s, 3H, OMe), 4.34
(s, 2H, CH2), 6.81 (dd, 2H, ortho to OMe), 7.11 (dd, 2H, meta to OMe), 7.26
(d, 1H, naphth), 7.72 (d, 1H, naphth), 7.34–7.50 (m, 3H, naphth), 7.93 (d, 1H,
naphth), 8.0 (d, 1H, naphth). 13C NMR, d: 157, 140, 135, 134, 130, 129, 127.5,
126.5, 125.5, 125.3, 125, 121, 116, 55, 41. MS: m/z 248. Anal. Calcd for
C18H16O: C, 87.09%; H, 6.48%. Found: C, 87.03%; H, 6.32%.
(4-Methoxyphenyl)-(3-methyl-4-hydroxyphenyl)-naphth-1-yl-methane
(6). M.p.: 126–1288C. IR (KBr, cm21): 3400 (OH), 1600, 1500 (ArH).
1H NMR (d, CDCl3): 2.14 (s, 3H, CH3), 3.74 (s, 3H, OMe), 4.61 (s, 1H,
OH), 6.12 (s, 1H, CH), 6.64 (dd, 1H, Ar-H, ortho to OH), 6.80 (dd, 2H,
ortho to OMe), 6.86 (s, 1H, Ar-H, ortho to CH3), 6.93 (d, 1H, naphth), 7.01
(dd, 2H, Ar-H, meta to OMe), 7.32–7.43 (m, 3H, naphth), 7.72 (d, 1H,
naphth), 7.84 (d, 1H, naphth), 7.94 (d, 1H, naphth), 6.74 (dd, 1H, ArH,
meta to OH). 13C NMR, d: 157.5, 153, 137, 135.5, 134.5, 134.7, 133.5, 133,
130.5, 130, 128, 127–126 (4C), 124, 118, 117, 116.5, 54, 51, 21, 120 MS:
m/z 354. Anal. Calcd for C25H22O2: C, 84.74%; H, 6.21%. Found: C,
84.31%; H, 6.28%.