Convenient synthesis of 1-arylmethyl-2-naphthols

Article abstract of DOI:10.1080/00397910601163547

A new environmentally benign, two-step procedure for the synthesis of 1-arylmethyl-2-naphthols in good to excellent yield is reported. It involves microwave-assisted facile formation of Mannich bases of 2-naphthol under solvent-free conditions and subsequ

Full text of DOI:10.1080/00397910601163547

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Convenient Synthesis of
1‐Arylmethyl‐2‐naphthols
Nawal K. Paul a , Lindsay Dietrich a & Amitabh Jha a
a Department of Chemistry , Acadia University , Wolfville, NS, Canada
Published online: 24 Feb 2007.
To cite this article: Nawal K. Paul , Lindsay Dietrich & Amitabh Jha (2007) Convenient Synthesis of
1‐Arylmethyl‐2‐naphthols , Synthetic Communications: An International Journal for Rapid Communication of
Synthetic Organic Chemistry, 37:6, 877-888, DOI: 10.1080/00397910601163547
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Synthetic Communicationsw, 37: 877–888, 2007
Copyright # Taylor & Francis Group, LLC
ISSN 0039-7911 print/1532-2432 online
DOI: 10.1080/00397910601163547
Convenient Synthesis of 1-Arylmethyl-
2-naphthols
Nawal K. Paul, Lindsay Dietrich, and Amitabh Jha
Department of Chemistry, Acadia University, Wolfville, NS, Canada
Abstract: A new environmentally benign, two-step procedure for the synthesis of
1-arylmethyl-2-naphthols in good to excellent yield is reported. It involves
microwave-assisted facile formation of Mannich bases of 2-naphthol under solvent-
free conditions and subsequent Pd-catalyzed deamination, leading to formation of
title compounds.
Keywords: 1-arylmethyl-2-naphthols, deamination, microwave, solvent free, Pd
catalyzed
The naphthalene nucleus is commonly found in compounds of commercial
importance. A number of pharmaceutical and agricultural agents have a
naphthalene framework. Some of the commonly known examples include
LY326315 (a selective estrogen receptor modulator),[1] naproxen and nabume-
tone (nonsteroidal anti-inflammatory drugs),[2,3] naphazoline and pronethalol
(cardiovascular agents),[4,5] 1-napthaleneacetic acid and 2-naphthoxyaceticacid
(plant growth regulators),[6,7] and terbinafine and naftifine (antifungal
agents).[8,9] In the literature, 2-naphthol and 2-naphthol derivatives are also
reported as bactericides[10] and antioxidants.[11]
Because of the wide variety of practical application of the naphthalene
nucleus as a building block, it is paramount to develop synthetic strategies
around this nucleus to gain easy access to variety of naphthalene derivatives.
Substitution at position 1 of the naphthalene ring, as seen in molecules such as
Received in the USA August, 28 2006
This paper was presented at International Congress of Chemistry and Environment
2005, Indore, India.
Address correspondence to Amitabh Jha, Department of Chemistry, Acadia Univer-
sity, Wolfville, NS, B4P 2R6, Canada. E-mail: amitabh.jha@acadiau.ca
877

878
N. K. Paul, L. Dietrich, and A. Jha
Figure 1. Molecular structures of representative 1-substituted naphthalene deriva-
tives of pharmaceutical importance.
LY326315, naphazoline, and terbinafine (Fig. 1), is of particular interest for
this group. We are using ambident nucleophile 2-naphthol in our studies.
Various methods are known for the substitution of 2-naphthol at position
1[12–27] including Zn-mediated thermal transfer of the benzyl group from
benzylaryl ether to 2-naphthol,[12] thermal rearrangement of 2-benzyloxy-
naphthalene,[12] nuclear arylmethylation of 2-naphthol alkali metal salts using
corresponding halides,[13,16,18,19] Clemmensen reduction of aryl 1-(2-hydroxy-
naphthyl)ketone,[24] and other, more cumbersome procedures.[15,20–23] Many
of these procedures have serious drawbacks, for example, formation of side
product(s), low yield, use of elevated temperature, and long reaction
time.[12,13,15,16,19,20,22,23]
Over the past few years, microwave irradiation has become a common
and efficient energy source in the chemical and pharmaceutical industry.[28]
The exorbitant increase in number of publications dealing with this subject
emphasizes the promising potential of microwave-accelerated syntheses that
has not yet been discovered completely. Microwave-accelerated reactions
still reveal fascinating opportunities concerning reaction course, rate, and
yield. Microwave chemistry is particularly effective in dry media reaction.
Microwave generate rapid intense heating of polar substances, resulting in
significantly reduced reaction times, cleaner reactions, and, in many cases,
higher yields.
We herein report a novel, convenient, and highly efficient method for the
preparation of 1-arylmethyl-2-naphthols in good to excellent yields involving
two steps. It involves formation of 2-naphthol Mannich bases (1–9) followed by
catalytic deamination leading to 1-arylmethyl-2-naphthols (10–16) (Fig. 2).
Both steps can be carried out under microwave irradiation conditions with a
total reaction time of less than 3 min.
The interest of this laboratory lies in the use of 2-naphthol and its dihydro
derivative 2-tetralone as versatile building block for generation of molecular
framework of medicinal importance.[29–32] In our previous work,[30,31] we
devised an excellent procedure to prepare 1-arylmethyl-2-alkoxynaphthalenes
(C) from 2-tetralone, aromatic aldehydes, and alcohols under anhydrous
acidic conditions (Scheme 1). It appeared quite logical that replacement of
alcohol (ROH) with water (HOH) in this synthetic scheme should lead to

Convenient Synthesis of 1-Arylmethyl-2-naphthols
879
Figure 2. Molecular structures of 2-naphthol Mannich base precursors (1–9) and
1-arylmethyl-2-naphthols (10–15).
formation of 1-arylmethyl-2-naphthol (C, R55H), but such an attempt failed to
produce any result. 1-Arylmethyl-2-naphthols (C, R55H) can also be viewed
as constitutional isomers of 1-arylidene-2-tetralones (A). Because 1-aryl-
methyl-2-naphthols (C, R55H) are aromatic, a conversion from A to C
(R55H) should be rather facile, but after numerous attempts, including
reaction via formation of easily cleavable silyl enol ethers (B, R55SiMe3)
and enol esters (B, R55COCF3), we failed to achieve this.[30]
We then decided to utilize an alternate and novel procedure to make
1-arylmethyl-2-naphthols (C, R55H) starting from 2-naphthol (Scheme 2).
This involved facile formation of 2-naphthol Mannich bases (1–9)[29,33]
followed by reductive cleavage of the C-N bond, furnishing the desired
compounds (10–15). We employed a modified literature procedure[29] that
involved use of a microwave to prepare Mannich bases of 2-naphthol expedi-
tiously. Instead of acidic alumina used in the literature procedure,[33] we
utilized catalytic quantities of p-toluenesulfonic acid under solvent-free
conditions.[29] We achieved moderate to excellent yields (Table 1) of
2-naphthol Mannich bases (1–9) and were able to reduce the reaction time
from 5 min to 1 min. The use of Pd-catalyzed hydrogenolysis is a widely
used procedure for reductive deamination of benzylic amines.[34] The
Scheme 1. Synthesis of 1-arylmethyl-2-alkoxynaphthalene.

880
N. K. Paul, L. Dietrich, and A. Jha
Scheme 2. Synthetic route followed for the preparation of 2-naphthol Mannich bases
(1–9) and 1-arylmethyl-2-naphthols (10–15).
Mannich bases were subjected to Pd/C-catalyzed reductive deamination in
methanol utilizing ammonium formate as source of hydrogen gas under
conventional heating conditions. It look 1–2 h for the reaction to go to com-
pletion as witnessed by thin-layer chromatography (TLC). The isolated yield
and the purity of the products (10–15) were excellent. Chloro-and nitro-
substituents on compounds 4 and 6 were also reduced during hydrogenation
as expected, yielding compounds 10 and 12, respectively.
This type of reductive deamination is known under microwave conditions
as well,[34] so we carried out a few representative reactions under microwave
irradiation, and the reaction indeed worked as efficiently in 1 min. The results
are appended in Table 1 as footnotes.
Formation of these products was easily confirmed by disappearance of
aliphatic protons of the N-heterocycle in NMR and shifting of the -OH
signal from d 12–14 for 2-naphthol Mannich bases (1–9) to ꢀd 9 for 1-aryl-
methyl-2-naphthols (12–15), where DMSO-d6 was used as solvent; this peak
did not appear in the case of CDCI3 as NMR solvent. The shifting of the OH
signal indicated that there existed a strong hydrogen bonding between -OH of
the naphthol and heterocyclic N in Mannich bases, which disappeared after
hydrogenation. The presence of the H-bond in the Mannich base series
(1–9) was also confirmed by X-ray crystallographic analyses of represen-
tative examples.[29] Moreover, the benzylic proton in 1-arylmethylnaphthols
(10–15) integrated for two protons as opposed to one proton in case of
2-naphthol Mannich bases (1–9). HR-MS data were in perfect agreement
with the structures.
CONCLUSION
We have devised an elegant procedure for the synthesis of 1-arylmethyl-
2-naphthols starting from 2-naphthol, an economical and readily available
starting material, involving two extremely efficient microwave-assisted
reactions. This constitutes a novel procedure where secondary amines were
used to aid the selective insertion of the arylmethyl group at position 1 of
2-naphthol. Chemical modifications on the 1-arylmethyl-2-naphthol
framework are in progress to produce compounds of medicinal interest.

Table 1. Reaction data for the preparation of 2-naphthol Mannich bases (1–9) and 1-arylmethyl-2-naphthols (10–15)
2-Naphthol Mannich bases 1-Arylmethyl-2-naphthols
Compd.
Time (min)
Yield (%)
79.7
Mp (lit. mp) in 8C
Compd.
Time (min)
Yield (%)
82.0
Mp (lit. mp) in 8C
1
1
1
1
1
192–194
(198–199)[35]
177–179
(181–183)[35]
172–174
10
120
60
109–111
(111–112)[27]
110–111
(111–112)[27]
109–110
(111–112)[27]
107–108
2
3
4
85.8
77.0
72.0
10a
10
92.9
72.8
59.3
120
120
165–166
10
(111–112)[27]
—
176–182
5
6
7
1
1
1
82.7
83.3
62.0
144–146
186–188
137–140
11
12
13a
120
90
64.1
58.6
54.2
120
129–130
(130–131)[26]
213–216
97–99
8
9
1
1
82.4
61.1
185–187
168–170
14
15a
120
120a
84.0
84.0
aAlso carried out by microwave irradiation (cf. Experimental, method B). Data obtained is as under (Compound, reaction time in minute, percen-
tage yield): 10, 1, 71; 13, 1, 77; 15, 1, 65.

882
N. K. Paul, L. Dietrich, and A. Jha
EXPERIMENTAL
General
2-Naphthol, cyclic secondary amines, aromatic aldehydes, p-toluenesulfonic
acid, ammonium formate, and 10% Pd/C were obtained from Aldrich
Chemical Co. 1H NMR and 13C NMR were recorded on a Bruker AV300 spec-
trophotometer at 300 MHz and 75 MHz, respectively. Melting points were
recorded on a MEL-TEMP II apparatus and are uncorrected. EI-MS and HR-
MS spectra were obtained on CEC 21-110B Sector instrument. UV-Vis and
IR spectra were recorded on LKB Biochrom Ultraspec Plus 4054 and Nicolet
Avatar 330FT-IR spectrophotometers respectively. A domestic microwave
oven manufactured by Kenmore was used for the microwave-assisted
reactions at highest power (900 W) and 2450-MHz operating frequency.
General Procedure for the Synthesis of 2-Naphthol Mannich
Bases (1–9)
2-Naphthol Mannich bases were prepared by a recent modification[29] of a
literature procedure[33] where a catalytic amount of p-toluenesulfonic acid
was used without solid support. Products were obtained in good to excellent
yields. The reaction data is summarized in Table 1.
Data
1
1-(Phenyl-piperidin-1-yl-methyl)-2-naphthol (1). H and 13C NMR were
identical to those reported in literature.[35] IR, UV-Vis, EI-MS, and HR-MS
data for this compound have been recently reported by our group.[29]
1
1-(Morpholin-4-yl-phenylmethyl)-2-naphthol (2). H and 13C NMR were
identical to those reported in literature.[35] IR, UV-Vis, EI-MS, and HR-MS
data for this compound have been recently reported by our group.[29]
1-(Phenyl-pyrrolidin-1-yl-methyl)-2-naphthol (3). 1H NMR (300 MHz,
293 K, CDCl3) d: 1.86–1.91 (4H, m, 4 ꢀ CH), 2.10–2.73 (3H, m,
3 ꢀ NCH), 3.21–3.41 (1H, m, NCH), 5.15 (1H, s, Ar-CH-Ar0), 7.16–7.32
(5H, m, Ar0-H), 7.36–7.42 (1H, m, Ar-H), 7.61–7.74 (4H, m, Ar-H), 7.89–
7.92 (1H, m, Ar-H) 13.90 (1H, bs, OH). 13C NMR (75 MHz, 273 K,
CDCl3)d: 23.80, 52.79, 55.25, 71.18, 116.94, 117.01, 120.36, 121.53,
122.87, 126.86, 128.34, 128.90, 129.16, 129.96, 130.02, 132.18, 141.49,
and 155.82. IR, KBr Disc, v: 3442, 3060, 2982, 1621, 1500, 1471, 1383,
1239, and 751 cm21. UV-Vis, MeOH. lmax: 245, 280, 290, and 335 nm. EI-
MS (70 eV) m/z (% int.): 303 (Mþ, 4), 233 (2), 232 (65), 231 (l00), 70 (7).
HR-MS calcd. for C21H21NO: 303.1623; found: 303.1626.

Convenient Synthesis of 1-Arylmethyl-2-naphthols
883
1-(4-Chlorophenyl)-piperidin-1-yl-methyl)-2-naphthol (4). 1H and 13C
NMR, IR, UV-Vis, EI-MS, and HR-MS data for this compound have been
recently reported by our group.[29]
1-(4-Methylphenyl)-piperidin-1-yl-methyl)-2-naphthol (5). 1H NMR
(300 MHz, 273 K, CDCl3) d: 1.41 (1H, bs, CH), 1.50–1.91 (5H, m,
5 ꢀ CH), 2.27–2.46 (4H, m, Ar-CH3, NCH), 2.92 (1H, bs, NCH), 3.23
(1H, bs, NCH), 3.53 (1H, bs, NCH), 5.23 (1H, s, Ar-CH-Ar0), 7.01–7.08
(1H, m, Ar-H), 7.22–7.28 (2H, m, Ar-H), 7.37–7.42 (3H, m, Ar-H), 7.49–
7.52 (2H, m, Ar-H), 7.68–7.73 (1H, m, Ar-H), 7.81–7.84 (1H, m, Ar-H),
and 13.32 (IH, bs, OH). 13C NMR (75 MHz, 273 K, CDCl3) d: 21.63,
24.03, 25.72, 26.00, 52.10, 55.20, 64.90, 109.00, 117.82, 120.33, 121.24,
123.06, 126.22, 127.10, 129.11, 129.47, 130.25, 130.87, 134.88, and
155.36. IR, KBr Disc, v: 3439, 3060, 2963, 1621, 1595, 1384, 1359, 1261,
1231, and 821 cm21. UV-Vis, MeOH, lmax: 244, 291, and 336 nm. EI-MS
(70 eV), m/z (% int.): 331 (Mþ, 14), 247 (10), and 231 (100). HR-MS
calcd. for C23H25NO: 331.1936; found: 331.1930.
1-(4-Nitrophenyl)-piperidin-1-yl-methyl)-2-naphthol (6). 1H and 13C
NMR, IR, UV-Vis, EI-MS, and HR-MS data for this compound have been
recently reported by our group.[29]
1-[(4-Methoxyphenyl)piperidin-1-yl-methyl]-2-naphthol (7). 1H NMR
(300 MHz, 273 K, CDCl3) d: 1.29–140 (1H, m, CH), 1.66–1.86 (5H, m,
5 ꢀ CH), 1.92–2.41 (2H, m, 2 ꢀ NCH), 2.74–2.91 (1H, m, NCH), 3.35–
3.49 (1H, m, NCH), 3.73 (3H, s, OCH3), 5.13 (1H, s, Ar-CH-Ar0), 6.78–
6.81(1H, m, Ar-H), 7.22–7.27 (2H, m, Ar-H), 7.39–7.43 (1H, m, Ar-H),
7.49–7.52 (2H, m, Ar-H), 7.67–7.74 (3H, m, Ar-H), 7.82–7.86 (1H, m,
Ar-H), 13.71 (1H, bs, OH). 13C NMR (75 MHz, 273 K, CDC13) d: 22.83,
24.35, 26.07, 52.15, 55.02, 55.59, 71.56, 114.48, 116.33, 120.37, 121.39,
122.85, 126.87, 129.07, 129.34, 129.85, 130.68, 131.46, 132.63, 155.52,
159.63. IR, KBr Disc, v: 3440, 3060, 2992, 1621, 1511, 1473, 1314, 1242,
1033 cm21. UV-Vis, MeOH. lmax: 244, 291, and 335 nm. EI-MS (70 eV)
m/z (% int.): 347 (1), 261 (100), 247 (2), 84 (19). HR-MS calcd. for
C23H25NO2: 347.1885; found: 347.1874.
1
1-(Piperidin-1-yl-pyridin-4-yl-methyl)-2-naphthol (8). H and 13C NMR,
IR, UV-Vis, EI-MS, and HR-MS data for this compound have been recently
reported by our group.[29]
1-(Morpholin-1-yl-pyridin-2-yl-methyl)-2-naphthol
(9).
1H
NMR
(300 MHz, CDCl3)d: 2.31–2.44 (2H, m, 2 ꢀ -NCH), 2.69–2.90 (2H, m,
2 ꢀ -NCH), 3.73–3.89 (4H, m, 4 ꢀ -OCH), 5.45 (1H, s, Ar-CH-Ar0), 7.13–
7.18 (2H, m, Ar-H), 7.25–7.31 (1H, m, Ar-H), 7.40–7.46 (1H, m, Ar-H),
7.55–7.74 (4H, m, Ar-H), 8.06–8.10 (1H, d, J ¼ 8.4 Hz, Ar-H), 8.57–8.60

884
N. K. Paul, L. Dietrich, and A. Jha
(1H, d, J ¼ 4.8 Hz, Ar-H) and 12.98 (1H, bs, OH). 13C NMR (75 MHz,
CDCl3)d: 52.96, 67.25, 73.94, 114.45, 120.16, 122.06, 123.22, 123.39,
123.79, 127.16, 129.16, 130.47, 133.02, 137.79, 149.42, 155.34, and
159.32. IR, KBr disc, v: 3439, 3040, 2934, 1621, 1592, 1451, 1384, 1262,
1236, and 819 cm21. UV-Vis, MeOH, lmax: 242 and 296 nm.
General Procedure for the Synthesis of 1-Arylmethyl-2-naphthols
(10–16)
Method A
A mixture of the appropriate 2-naphthol Mannich base (0.7 mmol),
ammonium formate (7 mmol), and Pd/C (40 mg, cat.) in methanol (15 ml)
was refluxed for 2 h. The reaction mixture was filtered on a celite bed, the
methanol was concentrated, and the product was extracted with ethyl
acetate and water. The dried (anhydrous Na2SO4) organic layer was rotary
evaporated to yield a solid product, which was washed with ice-cold dichlor-
omethane (3 ml). The product thus obtained was found to be pure upon TLC
examination.
Method B
A mixture of an appropriate 2-naphthol Mannich base (0.7 mmol),
ammonium formate (7 mmol), and 10% Pd/C (40 mg, cat.) was irradiated
by microwave in methanol (10 ml) for 1 min (2 ꢀ 30 s); methanol evapor-
ated completely. TLC was checked after dissolving the material in
methanol (5 ml), which showed appreciable conversion (ꢀ70–80%). It
was then filtered on a celite bed, the methanol was rotary evaporated,
and the product was extracted with ethyl acetate and water. The dried
organic layer was vacuum concentrated to dryness, and the resulting solid
product was washed with ice-cold dichloromethane (3 ml). It was found
to be pure upon TLC.
Data
1
1-Benzyl-2-naphthol (10). H NMR (300 MHz, CDCl3) d: 4.50 (2H, s, Ar-
CH2-Ar0), 7.05–7.24 (5H, m, Ar-H), 7.28–7.50 (2H, m, Ar-H), 7.74 (1H, d,
J ¼ 9 Hz, Ar-H), 7.84 (1H, d, J ¼ 8.1 Hz, Ar-H), 7.94–7.97 (2H, m, Ar-H).
13C NMR (75 MHz, CDCl3) d: 31.11, 118.31, 118.58, 123.68, 123.78,
126.58, 127.13, 128.64, 128.97, 128.99, 129.02, 129.90, 134.09, 140.40,
and 151.61. IR, KBr disc, v: 3423, 3060, 3027, 2938, 1630, 1602, 1474,
718 cm21. EI-MS (70 eV) m/z (% int.): 234 (Mþ, 100), 91 (5). HR-MS
calcd. for C17H14O: 234.1045; found: 234.1044.

Convenient Synthesis of 1-Arylmethyl-2-naphthols
885
1
1-(4-Methylbenzyl)-2-naphthol (11). H NMR (300 MHz, CDCl3) d: 2.32
(3H, s, Ar-CH3), 4.45 (2H, s, Ar-CH2-Ar0), 7.08–7.16 (4H, m, Ar-H),
7.34–7.48 (3H, m, Ar-H), 7.70–7.98 (3H, m, Ar-H). 13C NMR (75 MHz,
CDCl3) d: 21.43, 30.70, 118.36, 118.75, 123.62, 123.76, 126.78, 126.93,
127.08, 128.50, 128.87, 128.96, 129.74, 129.87, 134.08, and 151.66. IR,
KBr disc, v: 3435, 3026, 3017, 2972, 1615, 1600, 1468, 709 cm21. EI-MS
(70 eV) m/z (% int.): 248 (Mþ, 100), 156 (4), 144 (5), 105 (5). HR-MS
calcd. for C18H16O: 248.1201; found: 248.1195.
1-(4-Aminobenzyl)-2-naphthol (12). 1H NMR (300 MHz, DMSO-d6) d: 3.58
(2H, bs, NH2), 4.16 (2H, s, Ar-CH2-Ar0), 6.40 (2H, m, Ar0-H), 6.87 (2H, m,
Ar0-H), 7.21–7.39 (3H, m, Ar-H), 7.64–7.85 (3H, m, Ar-H), 9.63
(1H, bs, OH). 13C NMR (75 MHz, DMSO-d6) d: 29.89, 49.46, 114.70,
119.01, 119.73, 123.00, 124.09, 126.79, 128.24, 129.10, 129.19, 129.42,
134.18, 147.07, and 153.17. IR, KBr disc, v: 3420, 3359, 3298, 1631, 1613,
1512, 1384, 807, 745 cm21. EI-MS (70 eV) m/z (% int.): 249 (Mþ, 7), 144
(100), 115 (5), 93 (7). HR-MS calcd. for C17H15NO: 249.1154; found:
249.1148.
1
1-(4-Methoxybenzyl)-2-naphthol (13). H NMR (300 MHz, DMSO-d6) d:
3.65 (3H, s, O-CH3), 4.29 (2H, s, Ar-CH2-Ar0), 6.77 (2H, d, J ¼ 8.2 Hz,
Ar0-H), 7.08–7.41 (5H, m, Ar-H), 7.65–7.87 (3H, m, Ar-H), 9.72 (1H, bs,
OH). 13C NMR (75 MHz, DMSO-d6) d: 29.82, 55.76, 114.43, 118.99,
119.19, 123.08, 123.90, 126.96, 128.53, 128.95, 129.11, 129.15, 129.90,
134.08, 153.28, and 157.04. IR, KBr disc, v: 3367, 2926, 1630, 1607, 1584,
1510, 1384, 808, 745 cm21. EI-MS (70 eV) m/z (% int.): 264 (Mþ, 100),
108 (54). HR-MS calcd. for C18H16O2: 264.1150; found: 264.1152.
1-((Pyridine-4-yl)methyl)-2-naphthol (14). 1H NMR (300 MHz, DMSO-d6)
d: 4.36 (2H, s, Ar-CH2-Ar0), 7.18–7.39 (5H, m, Ar-H), 7.72–7.81 (3H, m, Ar-
H), 8.37–8.38 (2H, m, Ar-H), 10.10 (1H, bs, OH). 13C NMR (75 MHz,
DMSO-d6) d: 30.19, 117.02, 118.92, 123.28, 123.53, 124.56, 127.30,
129.06, 129.16, 129.29, 133.99, 150.17, 151.34, and 153.70. IR, KBr disc,
v: 3448, 3051, 2967, 2937, 1607, 1576, 1438, 1332, 1277, 808, 519 cm21
.
EI-MS (70 eV) m/z (% int.): 235 (Mþ, 100), 157 (2). HR-MS calcd. for
C16H13NO: 235.0997; found: 235.0993.
1-((Pyridine-2-yl)methyl)-2-naphthol (15). Prepared by methods A and B.
1H NMR (300 MHz, DMSO-d6) d: 4.49 (2H, s, CH2), 7.02–7.45 (5H, m,
Ar-H), 7.53–8.00 (4H, m, Ar-H), 8.48 (1H, d, J ¼ 8.2 Hz, Ar0-H), 9.98
(1H, bs, OH). 13C NMR (75 MHz, DMSO-d6) d: 34.14, 117.71, 119.17,
122.07, 123.16, 123.21, 123.97, 127.09, 128.23, 128.91, 129.10, 134.26,
137.55, 149.47, 153.59, and 161.88. IR, KBr disc, v: 3444, 3058, 2953,
2923, 1631, 1618, 1596, 1384, 750 cm21. EI-MS (70 eV) m/z (% int.): 235

886
N. K. Paul, L. Dietrich, and A. Jha
(Mþ, 100), 218 (83), 217 (18), 157 (2). HR-MS calcd. for C16H13NO:
235.0997; found: 235.0992.
ACKNOWLEDGMENTS
We are thankful to Natural Sciences and Engineering Research Council (NSERC),
the Human Resources and Skills Development Canada’s Summer Career
Placement Program, and Research Corporation (USA) for financial support.
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