New three-component condensation reaction: Synthesis of 1-[(alkylthio)(phenyl)methyl]-naphthalene-2-ol catalyzed by bromodimethylsulfonium bromide (BDMS)

Article abstract of DOI:10.1016/j.tetlet.2011.07.113

Bromodimethylsulfonium bromide acts as an efficient catalyst for one pot three component condensation reactions of aldehydes, 2-naphthol, and thiols in acetonitrile at room temperature. Various aliphatic and aromatic thiols undergo conjugate addition with

Full text of DOI:10.1016/j.tetlet.2011.07.113

Tetrahedron Letters 52 (2011) 5157–5160
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Tetrahedron Letters
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New three-component condensation reaction: synthesis of
1-[(alkylthio)(phenyl)methyl]-naphthalene-2-ol catalyzed by
bromodimethylsulfonium bromide (BDMS)
⇑
Abu T. Khan , Shahzad Ali, Ajaz A. Dar, Mohan Lal
Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781 039, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Bromodimethylsulfonium bromide acts as an efficient catalyst for one pot three component condensation
reactions of aldehydes, 2-naphthol, and thiols in acetonitrile at room temperature. Various aliphatic and
aromatic thiols undergo conjugate addition with in situ generated enone in acetonitrile and provide good
yields. The main features of this procedure are mild reaction conditions, good yields, and operational
simplicity.
Received 8 May 2011
Revised 24 July 2011
Accepted 26 July 2011
Available online 31 July 2011
Ó 2011 Elsevier Ltd. All rights reserved.
Keywords:
Bromodimethylsulfonium bromide (BDMS)
2-Naphthol
Thiols
Aromatic aldehyde
o-Quinone methides (o-QMs)
Thia-Michael reaction
Carbon–sulfur bond formation has versatile application in or-
ganic synthesis1 in view of many recent sulfur-containing natural
and pharmaceutical products, which have potent antibiotic, anti-
microbial, analgesic, anti-inflammatory, antipsychotic, anti-HIV,
and anti-tumor activities.2 1,4 Conjugate addition of a thiol nucle-
ophile to an acceptor (alkene or alkyne) activated by an electron-
withdrawing group namely the thia-Michael addition constitutes
an important C–S bond forming strategy in organic synthesis.3
The reported methods for thia-Michael addition are mainly fo-
cused on the use of acidic and basic catalysts for the direct addition
of thiols to Michael acceptors in organic solvents.
Both from an atom-economic point of view as well as simplicity
of the procedure, the thia-Michael addition is the preferred method
for the preparation of organosulfur compounds. An acid or a base
can be used as a promoter for this transformation. Over the years,
numerous methods have been reported using a variety of catalysts,
such as Cinchona alkaloid-squareamide,4a [LNi2(CH3CN)(THF)]
(ClO4)3,4b InCl3,4c silica nanoparticles,4d (IMesPr)AuCl,4e [Ru(ace-
tone)(R,R-BIPHOP-F)Cp][SbF6],4f cinchona alkaloid-derived urea,4g
NEt3,4h SDS/NaHCO3,4i Co/SBA-15,4j VO(OTf)2,4k silica–alumina sup-
ported NEt3.4l It is highly desirable to develop a convenient, envi-
ronment friendly method for the thia-Michael addition reaction.
In this paper, we report the use of BDMS as a highly useful catalyst
for the addition of thiols to the in situ generated enones from the
reaction of aromatic aldehydes and 2-naphthol. To the best of our
knowledge, these compounds are not reported till now.
Bromodimethylsulfonium bromide (BDMS) is a readily avail-
able, cheap, and highly efficient reagent5 as well as a catalyst for
various organic transformations.5 In continuation of the present
work on the development of new synthetic method, it has been ob-
served that bromodimethylsulfonium bromide efficiently catalyzes
the conjugate addition of various thiols to the in situ generated
enones at room temperature (as shown in Scheme 1).
In the beginning of our study, benzaldehyde, 2-naphthol, and
ethanethiol were chosen as model substrates. The reaction
conditions were optimized for the synthesis of the 1-[(ethyl-
thio)(phenyl)methyl]naphthalene-2-ol in terms of the yield and
reaction time. Several reactions were scrutinized using different
catalysts and various solvents, such as CH3CN, DCM, and EtOH.
The optimal amount of the reactants, such as benzaldehyde, 2-
naphthol, thiol, and BDMS was found to be 1.0, 1.0, 1.1, and
0.1 equiv, respectively (Table 1, entry 3). We have noted that no
X
CHO
+
OH
BDMS
+
R
SH
X
CH3CN/r.t.
R
S
HO
X = H, Cl ,Br, NO2, Me
R = C2H5, C3H7, HOCH2CH2, Ph, PhCH2, p-MeOC6H4, p-MeC6H4
⇑
Corresponding author. Tel.: +91 361 2582305; fax: +91 361 2582349.
E-mail address: atk@iitg.ernet.in (A.T. Khan).
Scheme 1. Synthesis of 1-[(alkylthio)(phenyl)methyl]naphthalene-2-ol.
0040-4039/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2011.07.113

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A. T. Khan et al. / Tetrahedron Letters 52 (2011) 5157–5160
Table 1
Optimization for reaction conditionsa
Entry
Catalyst
Solvent
Amount of catalyst (mol %)
Reaction Time (h)
Yieldb (%)
1
2
3
4
5
6
7
8
9
10
No catalyst
BDMS
BDMS
Acetonitrile
Acetonitrile
Acetonitrile
Acetonitrile
Acetonitrile
Acetonitrile
Acetonitrile
Acetonitrile
DCM
0
5
6.0
6.0
6.0
0
35
74
75
0
10
15
10
10
10
10
10
10
BDMS
6.0
Fe2(SO4)3H2O
CH3COOH
SiO2–HClO4
HBr–CH3COOH
BDMS
12.0
12.0
6.0
6.0
6.0
0
60
64
71
20
BDMS
Ethanol
6.0
a
All the reactions were carried out with 1 mmol scale.
Isolated yield.
b
Table 2
Synthesis of 1-[(alkylthio)(phenyl)methyl]naphthalene-2-ol7
Entry
Aldehydes
Thiols
Time (h)
Yielda (%)
1
2
3
4
5
6
7
8
Bezaldehyde
Benzaldehyde
Benzaldehyde
Ethanethiol
n-Propanethiol
Thiophenol
Ethanethiol
n-Propanethiol
Thiophenol
n-Propanethiol
Benzylthiol
Thiophenol
n-Propanethiol
p-Methoxythiophenol
Ethanethiol
6
6
8
5
5
7
6
6
8
6
5
6
5
5
5
6
6
7
74
73
21
77
78
62
81
71
30
80
72
59
77
65
70
20
73
—
p-Nitrobenzaldehyde
p-Nitrobenzaldehyde
p-Nitrobenzaldehyde
p-Chlorobenzaldehyde
p-Chlorobenzaldehyde
p-Chlorobenzaldehyde
p-Bromobenzaldehyde
p-Bromobenzaldehyde
p-Methylbenzaldehyde
m-Nitrobenzaldehyde
m-Nitrobenzaldehyde
m-Bromobenzaldehyde
o-Nitrobenzaldehyde
2-Naphthaldehyde
o-Chlorobenzaldehyde
9
10
11
12
13
14
15
16
17
18
Ethanethiol
Mercaptoethanol
p-Thiocresol
Ethanethiol
p-Thiocresol
Ethanethiol
a
Isolated yield.
product is formed in the absence of the catalyst. From this observa-
tion, it is obvious that BDMS plays an important role in the forma-
tion of the product.
8, 10–15, and 17). It was shown that the aromatic aldehydes
with electron withdrawing groups reacted faster than the aro-
matic aldehydes bearing electron donating groups as would be
expected. With thiophenol, p-chlorobenzaldehyde gives a low
yield of 30% (Table 2, entry 9) due to low electrophilicity of C-
atom of the aldehyde group in comparison to arylaldehyde bear-
ing nitro group at para position (62% yield, Table 2, entry 6).
Similarly, the reaction of thiophenol, benzaldehyde, and 2-naph-
thol provides only 21% yield due to less nucleophilicity of the
thiophenol. From these observations, it is quite clear that both
electrophilicity of the aldehydic carbon and nucleophilicity of
thiols play a crucial role for the formation of product. Further-
more, when o-nitrobenzaldehyde along with ethanethiol was ta-
ken, then the desired product was obtained in low yield (20%)
due to steric hindrance of nitro group at ortho-position (Table 2,
entry 16). In addition, when o-chlorobenzaldehyde along with
ethanethiol was used, then no desired product was obtained (Ta-
ble 2, entry 18). All these products were characterized by record-
ing melting point, IR, 1H NMR, 13C NMR spectra, and elemental
analysis.7
The formation of the 1-[(alkylthio)(phenyl)methyl]naphtha-
lene-2-ol products can be explained as follows: It has been
anticipated that bromodimethylsulfonium bromide may react with
2-naphthol to generate dry HBr in the reaction medium. The in situ
generated dry HBr catalyzes Knoevenagel condensation between
aromatic aldehydes and 2-naphthol to generate intermediate
ortho-quinone methides (o-QMs, A)6 as shown in Scheme 2. Then
the intermediate A reacts with thiol to give the desired thia-Mi-
chael product.
The reaction was studied with other catalysts namely acetic acid,
ferric sulfate, silica supported perchloric acid, and HBr–CH3COOH.
The best-suited catalyst for the reaction is BDMS. When 10 mol %
of BDMS was used, the reaction proceeded smoothly and the yield
was 74% (Table 1, entry 3). Moreover, the yield was found to be af-
fected by the amount of BDMS added. When 0.0, 5, and 15 mol % of
BDMS were used, the yield was 0.0%, 35%, and 75%, respectively
(Table 1, entries 1, 2, and 4). It was noted that 10 mol % of BDMS
was sufficient enough to carry out the reaction. Similarly, the role
of solvent in this reaction was studied. Accordingly, the reaction
was carried out in various solvents, such as acetonitrile, dichloro-
methane, and ethanol. It was found that acetonitrile is the most suit-
able solvent for this reaction.
Having established the optimized reaction condition, it was
decided to explore the scope of this domino thia-Michael con-
densation reaction. Thus, several thiols were treated with a vari-
ety of aromatic aldehydes bearing different substituents NO2, Br,
Cl, Me at different positions and 2-naphthol in the presence of
BDMS at room temperature in acetonitrile and the results were
summarized in Table 2. Almost all reactions worked well with
a variety of aromatic aldehydes including those bearing elec-
tron-withdrawing and electron-donating groups, such as NO2,
Br, Cl, and Me with ethanethiol, n-propanethiol, 2-mercap-
toethanol, p-thiocresol, p-methoxythiophenol, benzylthiol, and
thiophenol. The desired compounds were obtained in good to
high yields within short reaction time (Table 2, entries 1, 2, 4–

A. T. Khan et al. / Tetrahedron Letters 52 (2011) 5157–5160
5159
OH
Br
O
H
S
H
Br
S
HBr
+
Me
Me
+
O
Me
Me
Br
H+
H
Br
S
H
O
O
H
H
Me
Me
H
O
O
Br
-H2O
S
R
S
R
H
OH
O
A
Scheme 2. Proposed mechanism for the formation of product.
6. (a) Singh, R.; Panda, G. Org. Biomol. Chem. 2010, 8, 1097; (b) Snyder, S. A.;
Breazzano, S. P.; Ross, A. G.; Lin, Y.; Zografos, A. L. J. Am. Chem. Soc. 2009, 131,
1753; (c) Van De Water, R. W.; Pettus, T. T. R. Tetrahedron 2002, 58, 5367.
7. General procedure: To a mixture of aldehyde (1 mmol) and 2-naphthol (1 mmol)
in 3 mL of acetonitrile was added BDMS (0.1 mmol) and kept for stirring at room
temperature. Then the corresponding thiol (1.1 mmol) was added into it. The
reaction mixture was stirred at room temperature and the progress of the
reaction was monitored by TLC. After completion of the reaction, ethyl acetate
(25 mL) was added into it and the organic layer was washed with 10 mL of
water. The water layer was further extracted using ethyl acetate (2 Â 25 mL).
The combined organic layer dried over anhydrous sodium sulfate and it was
concentrated under rotary evaporator. The crude mixture was purified through
silica gel column chromatography and the desired product was obtained by
eluting with ethyl acetate and hexane (1:99) mixture.
In summary, a simple and efficient method for the one pot
multicomponent reaction for the synthesis of 1-[(alkylthio) (phe-
nyl) methyl] naphthalene-2-ol using aromatic aldehydes, 2-naph-
thol, and thiols catalyzed by bromodimethylsulfonium bromide
(BDMS) has been devised. The catalyst used is inexpensive and
efficient.
Acknowledgments
S.A., A.A.D, and M.L. are thankful to UGC (New Delhi), IIT
Guwahati and CSIR (New Delhi) for their research fellowships,
respectively. The authors are also grateful to the Director, IIT
Guwahati for providing the general research facility to carry out
this work. We are thankful to the referees for their valuable com-
ments and suggestions.
Spectral data:
1-((Ethylthio)(phenyl)methyl)naphthalen-2-ol (Table 2, entry 1): pale yellow
semi-solid; 1H NMR (400 MHz, CDCl3): d 1.22 (t, J = 7.6 Hz, 3H), 2.45–2.59 (m,
2H), 6.33 (s, 1H), 7.22 (d, J = 9.2 Hz, 2H), 7.27 (t, J = 8.0 Hz, 2H), 7.32 (d, J = 7.6 Hz,
1H), 7.38–7.44 (m, 3H), 7.78 (d, J = 7.6 Hz, 2H), 7.86 (d, J = 7.2 Hz, 1H), 9.08 (s,
1H, OH); 13C NMR (100 MHz, CDCl3): d 14.4, 26.8, 46.3, 113.5, 120.3, 121.8,
123.3, 127.2, 127.8, 128.4 (2C), 129.0 (2C), 129.2, 129.5, 130.5, 133.4, 138.6,
155.4; IR (KBr, cmÀ1): 3429 (OH); Anal. Calcd C19H18OS (294.41): requires C,
77.51; H, 6.16. Found C, 77.41; H, 6.22.
Reference and notes
1-(Phenyl(propylthio)methyl)naphthalen-2-ol (Table 2, entry 2): pale yellow
semi-solid; 1H NMR (400 MHz, CDCl3): d 0.93 (t, J = 8.0 Hz, 3H), 1.55–1.64 (m,
2H), 2.39–2.46 (m, 1H), 2.52–2.58 (m, 1H), 6.28 (s, 1H), 7.22 (d, J = 8.0 Hz, 2H),
7.26–7.33 (m, 3H), 7.39–7.43 (m, 3H), 7.79 (d, J = 8.4 Hz, 2H), 7.85 (d, J = 8.4 Hz,
1H), 9.14 (s, 1H, OH); 13C NMR (100 MHz, CDCl3): d 13.5, 22.4, 34.6, 46.7, 113.6,
120.3, 121.8, 123.3, 127.2, 127.8, 128.3 (2C), 128.9 (2C), 129.2, 129.5, 130.4,
133.4, 138.8, 155.3; IR (KBr, cmÀ1): 3439 (OH); Anal. Calcd C20H20OS (308.44):
requires C, 77.88; H, 6.54. Found C, 77.78; H, 6.49.
1. (a) Kondo, T.; Mitsudo, T.-A. Chem. Rev. 2000, 100, 3205; (b) Gilchrist, T. L.
Heterocyclic Chemistry, 3rd ed.; Addison Wesley Longman: Essex, 1997; (c)
Okazaki, R. In Organosulfur Chemistry; Academic: London, 1995; Vol. 1, p 225.
2. (a) Czarnik, A. W. Acc. Chem. Res. 1996, 29, 112; (b) Nguyen-Ba, N.; Brown, W. L.;
Chan, L.; Lee, N.; Brasili, L.; Lafleur, D.; Zacharie, B. Chem. Commun. 1999, 1245;
(c) Ashizawa, T.; Kawashima, K.; Kanda, Y.; Gomi, K.; Okabe, M.; Ueda, K.;
Tamaoki, T. Anticancer Drugs 1999, 10, 829; (d) Dewick, P. M. Medicinal Natural
Products, 2nd ed.; John Wiley
Vardanyan, R. S.; Hruby, V. J. Synthesis of Essential Drugs; Elsevier: Amsterdam,
2006.
&
Sons: West Sussex, England, 2002; (e)
1-(Phenyl(phenylthio)methyl)naphthalen-2-ol (Table 2, entry 3): pale yellow
semisolid. 1H NMR (400 MHz, CDCl3): d 6.62 (s, 1H), 7.10–7.16 (m, 4H), 7.23–
7.36 (m, 7H), 7.51 (dd, J1 = 1.2 Hz, J2 = 6.4 Hz, 2H), 7.69–7.73 (m, 2H), 7.80 (d,
J = 8.8 Hz, 1H), 8.25 (s, 1H, OH) ppm; 13C NMR (100 Hz, CDCl3): d 50.6, 115.4,
119.8, 122.3, 123.3, 127.0, 127.7, 127.9, 128.5 (2C), 129.0 (3C), 129.1 (2C), 129.5,
130.4, 131.0 (2C), 132.9, 134.1, 138.5, 154.1 ppm; IR (KBr, cmÀ1: 3445 (–OH);
Anal. Calcd C23H18OS (342.45): requires C, 80.67; H, 5.30. Found C, 80.49; H,
5.21.
1-((Ethylthio)(4-nitrophenyl)methyl)naphthalen-2-ol (Table 2, entry 4): pale
yellow solid, mp 127–129 °C; 1H NMR (400 MHz, CDCl3): d 1.25 (t, J = 7.6 Hz,
3H), 2.49–2.65 (m, 2H), 6.36 (s, 1H), 7.22 (d, J = 8.8 Hz, 1H), 7.33 (t, J = 7.6 Hz,
1H), 7.43 (t, J = 8.0 Hz, 1H), 7.57 (d, J = 8.4 Hz, 2H), 7.77–7.83 (m, 3H), 8.11 (d,
J = 8.8 Hz, 2H), 8.61 (s, 1H, OH); 13C NMR (100 MHz, CDCl3): d 14.4, 27.1, 45.4,
113.2, 120.1, 121.7, 123.7, 124.0 (2C), 127.5, 129.4 (3C), 129.6, 131.0, 133.0,
146.6, 147.3, 154.9; IR (KBr, cmÀ1: 3432 (OH), 1514 (NO2), 1346 (NO2); Anal.
Calcd C19H17NO3S (339.41): requires C, 67.24; H, 5.05; N, 4.13. Found C, 67.12;
H, 4.97; N, 4.05.
3. Perlmutter, P. Conjugate Addition Reactions in Organic Synthesis; Pergamon:
Oxford, 1992.
4. (a) Dai, L.; Wang, S.-X.; Chen, F.-E. Adv. Synth. Catal. 2010, 352, 2137; (b) Lee, W.-
Z.; Tseng, H.-S.; Wang, T.-L.; Tsai, H.-L.; Kuo, T.-S. Organometallics 2010, 29,
2874; (c) Dia, R.-M.; Belaqziz, R.; Romane, A.; Antoniotti, S.; Dunach, E.
Tetrahedron Lett. 2010, 51, 2164; (d) Banerjee, S.; Das, J.; Alvarez, R. P.; Santra,
S. New J. Chem. 2010, 34, 302; (e) Corma, A.; Gonzalez-Arellano, C.; Iglesias, M.;
Sanchez, F. App. Catal. A General 2010, 375, 49; (f) Badoiu, A.; Bernardinelli, G.;
Besnard, C.; Kundig, E. P. Org. Biomol. Chem. 2010, 8, 193; (g) Rana, N. K.;
Selvakumar, S.; Singh, V. K. J. Org. Chem. 2010, 75, 2089; (h) O’Byrne, A.; Murray,
C.; Keegan, D.; Palacio, C.; Evans, P.; Morgan, B. S. Org. Biomol. Chem. 2010, 8,
539; (i) Firouzabadi, H.; Iranpoor, N.; Abbasi, M. Adv. Synth. Catal. 2009, 351,
755; (j) Rajabi, F.; Razavi, S.; Luque, R. Green Chem. 2010, 12, 786; (k) Chen, C.-T.;
Lin, Y.-D.; Liu, C.-Y. Tetrahedron 2009, 65, 10470; (l) Motokura, K.; Tanaka, S.;
Tada, M.; Iwasawa, Y. Chem. Eur. J. 2009, 15, 10871. and references cited therein.
5. Choudhury, L. H.; Parvin, T.; Khan, A. T. Tetrahedron 2009, 65, 9513. and
references cited therein.
1-((4-Nitrophenyl)(propylthio)methyl)naphthalen-2-ol (Table 2, entry 5): pale
yellow semi-solid; 1H NMR (400 MHz, CDCl3): d 0.95 (t, J = 7.6 Hz, 3H), 1.58–
1.65 (m, 2H), 2.44–2.51 (m, 1H), 2.57–2.63 (m, 1H), 6.32 (s, 1H), 7.23

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A. T. Khan et al. / Tetrahedron Letters 52 (2011) 5157–5160
(d, J = 8.4 Hz, 1H), 7.35 (t, J = 7.2 Hz, 1H), 7.44 (t, J = 9.2 Hz, 1H), 7.58 (d,
1-((Ethylthio)(p-tolyl)methyl)naphthalen-2-ol (Table 2, entry 12): pale yellow
semi-solid; 1H NMR (400 MHz, CDCl3): d 1.18 (t, J = 7.6 Hz, 3H), 2.24 (s, 3H),
2.40–2.55 (m, 2H), 6.28 (s, 1H), 7.05 (d, J = 8.0 Hz, 2H), 7.20 (d, J = 8.8 Hz, 1H),
7.27 (t, J = 8.8 Hz, 1H), 7.28 (d, J = 7.6 Hz, 2H), 7.38 (t, J = 8.4 Hz, 1H), 7.75 (d,
J = 8.8 Hz, 2H), 7.84 (d, J = 8.8 Hz, 1H), 9.09 (s, 1H, OH); 13C NMR (100 MHz,
CDCl3): d 14.3, 21.2, 26.7, 46.0, 113.7, 120.2, 121.8, 123.2, 127.1, 128.2 (2C),
129.1, 129.4, 129.6 (2C), 130.3, 133.3, 135.6, 137.5, 155.3; IR (KBr, cmÀ1: 3417
(OH); Anal. Calcd C20H20OS (308.44): requires C, 77.88; H, 6.54. Found C, 77.79;
H, 6.46.
1-((Ethylthio)(3-nitrophenyl)methyl)naphthalen-2-ol (Table 2, entry 13): pale
yellow semi-solid; 1H NMR (400 MHz, CDCl3): d 1.25 (t, J = 7.2 Hz, 3H), 2.50–
2.65 (m, 2H), 6.37 (s, 1H), 7.24 (d, J = 8.8 Hz, 1H), 7.35 (d, J = 7.2 Hz, 1H), 7.40–
7.47 (m, 2H), 7.67 (d, J = 8.0 Hz, 1H), 7.78–7.84 (m, 3H), 8.09 (d, J = 8.4 Hz, 1H),
8.35 (s, 1H), 9.30 (s, 1H, OH); 13C NMR (100 MHz, CDCl3): d 14.4, 27.1, 45.3,
115.0, 120.3, 121.5, 122.8, 123.6, 123.7, 127.5, 129.4, 129.7, 129.9, 130.1, 133.0,
134.5, 141.2, 148.7, 155.2; IR (KBr, cmÀ1: 3445 (OH), 1527 (NO2), 1349 (NO2);
Anal. Calcd C19H17NO3S (339.41): requires C, 67.24; H, 5.05, N, 4.13. Found C,
67.12; H, 5.14, N, 4.21.
1-(((2-Hydroxyethyl)thio)(3-nitrophenyl)methyl)naphthalen-2-ol (Table 2,
entry 14): pale yellow solid, mp 142–145 °C; 1H NMR (400 MHz, CDCl3): d
2.31 (brs, 1H), 2.75 (q, J = 5.6 Hz, 2H), 3.81 (s, 2H), 6.50 (s, 1H), 7.20 (d, J = 8.8 Hz,
1H), 7.32 (t, J = 8.0 Hz, 1H), 7.39 (t, J = 9.2 Hz, 1H), 7.41 (t, J = 8.0 Hz, 1H), 7.68 (d,
J = 8.0 Hz, 1H), 7.74 (d, J = 8.4 Hz, 1H), 7.79 (d, J = 8.4 Hz, 2H), 8.08 (d, J = 8.0 Hz,
1H), 8.39 (s, 1H), 9.80 (s, 1H, OH); 13C NMR (100 MHz, CD3OD): d 36.3, 45.0, 62.4,
118.6, 119.3, 122.3, 123.7, 123.8, 125.8, 126.8, 129.9, 130.2, 131.0, 133.1, 135.3,
145.6, 149.4, 154.1; IR (KBr, cmÀ1: 3531 (OH), 1531 (NO2), 1351 (NO2); Anal.
Calcd C19H17NO4S (355.41): requires C, 64.21; H, 4.82, N, 3.94. Found C, 64.12; H,
4.71, N, 3.81.
1-((3-Bromophenyl)(p-tolylthio)methyl)naphthalen-2-ol (Table 2, entry 15):
pale yellow semi-solid; 1H NMR (400 MHz, CDCl3): d 2.20 (s, 3H), 6.57 (s, 1H),
6.97 (d, J = 8.0 Hz, 2H), 7.16 (t, J = 8.0 Hz, 1H), 7.21 (d, J = 8.8 Hz, 1H), 7.31 (t,
J = 7.2 Hz, 1H), 7.35 (d, J = 8.0 Hz, 2H), 7.38–7.43 (m, 2H), 7.46 (d, J = 7.6 Hz, 1H),
7.73–7.77 (m, 3H), 7.80 (d, J = 8.8 Hz, 1H), 8.32 (s, 1H, OH); 13C NMR (100 MHz,
CDCl3): d 21.1, 50.7, 115.0, 119.7, 122.2, 122.9, 123.4, 127.1 (2C), 129.0, 129.5,
130.0 (2C), 130.4, 130.5, 130.9, 131.5 (2C), 131.8 (2C), 132.8, 138.3, 141.2, 153.9;
IR (KBr, cmÀ1: 3436 (OH); Anal. Calcd C24H19BrOS (435.38): requires C, 66.21; H,
4.40. Found C, 66.12; H, 4.34.
1-((Ethylthio)(2-nitrophenyl)methyl)naphthalen-2-ol (Table 2, entry 16): pale
yellow semi-solid; 1H NMR (400 MHz, CDCl3): d 1.25 (s, J = 7.6 Hz, 3H), 2.56–
2.64 (m, 2H), 7.23 (s, 1H), 7.25 (d, J = 9.2 Hz, 1H), 7.28 (dd, J1 = 3.6 Hz, J2 = 5.6 Hz,
1H), 7.34 (t, J = 6.8 Hz, 1H), 7.38 (dd, J1 = 3.6 Hz, J2 = 6.4 Hz, 2H), 7.46 (t,
J = 7.6 Hz, 1H), 7.80 (d, J = 8.0 Hz, 1H), 7.84 (d, J = 9.2 Hz, 1H), 7.91 (d, J = 8.4 Hz,
1H), 7.95 (dd, J1 = 3.6 Hz, J2 = 5.6 Hz, 1H), 9.55 (s, 1H, OH); 13C NMR (100 MHz,
CDCl3): d 13.9, 27.7, 41.4, 111.4, 120.5, 121.9, 123.7, 125.7, 127.8, 129.0, 129.2,
129.6, 130.6, 131.2, 133.0, 133.5, 133.6, 149.1, 156.5; IR (KBr, cmÀ1: 3433 (OH),
1528 (NO2), 1353 (NO2); Anal. Calcd C19H17NO3S (339.41): requires C, 67.24; H,
5.05, N, 4.13. Found C, 67.12; H, 5.14, N, 4.19.
1-(Naphthalen-2-yl(p-tolylthio)methyl)naphthalen-2-ol (Table 2, entry 17):
White solid, mp 117–120 °C; 1H NMR (400 MHz, CDCl3): d 2.20 (s, 3H), 6.68 (s,
1H), 6.95 (d, J = 7.6 Hz, 2H), 7.21 (d, J = 9.2 Hz, 1H), 7.26 (t, J = 7.6 Hz, 1H), 7.32 (d,
J = 8.0 Hz, 2H), 7.33 (t, J = 7.6 Hz, 1H), 7.41–7.46 (m, 2H), 7.67 (dd, J1 = 2.0 Hz,
J2 = 8.8 Hz, 1H), 7.72–7.76 (m, 3H), 7.77–7.82 (m, 3H), 7.87 (s, 1H), 8.51 (s, 1H,
OH); 13C NMR (100 MHz, CDCl3): d 21.2, 51.9, 115.0, 120.2, 122.2, 123.3, 126.4
(2C), 126.7, 127.1, 127.4, 127.7, 128.3, 128.9, 129.0, 129.5, 130.0 (2C), 130.5,
131.7 (3C), 133.0, 133.1, 133.6, 135.9, 138.2, 154.6; IR (KBr, cmÀ1: 3434 (OH);
Anal. Calcd C28H22OS (406.54): requires C, 82.72; H, 5.45. Found C, 82.82; H, 5.54.
J = 8.4 Hz, 2H), 7.77 (d, J = 8.4 Hz, 1H), 7.82 (d, J = 8.0 Hz, 1H), 7.83 (d, J = 9.2 Hz,
1H), 8.13 (d, J = 8.8 Hz, 2H), 8.71 (s, 1H, OH); 13C NMR (100 MHz, CDCl3): d 13.6,
22.5, 35.0, 45.9, 113.4, 120.2, 121.7, 123.8, 124.1 (2C), 127.6, 129.5 (3C), 129.7,
131.1, 133.1, 146.8, 147.4, 155.1; IR (KBr, cmÀ1: 3437 (OH), 1518 (NO2), 1346
(NO2); Anal. Calcd C20H19NO3S (353.43): requires C, 67.97; H, 5.42; N, 3.96.
Found C, 67.84; H, 5.31; N, 3.87.
1-((4-Nitrophenyl)(phenylthio)methyl)naphthalen-2-ol (Table 2, entry 6): pale
yellow semi-solid; 1H NMR (400 MHz, CDCl3): d 6.68 (s, 1H), 7.05 (t, J = 7.2 Hz,
1H), 7.10–7.18 (m, 5H), 7.29 (d, J = 7.6 Hz, 2H), 7.56 (d, J = 8.8 Hz, 2H), 7.60–7.64
(m, 3H), 7.95 (d, J = 8.8 Hz, 2H), 9.52 (s, 1H, OH); 13C NMR (100 MHz, CDCl3): d
49.0, 116.8, 118.6, 123.1, 123.5, 123.6 (2C), 126.9, 127.5, 129.0 (2C), 129.1 (3C),
129.6, 130.5, 130.7 (2C), 132.2, 134.7, 146.6, 147.8, 152.3; IR (KBr, cmÀ1: 3437
(OH), 1515 (NO2), 1345 (NO2); Anal. Calcd C23H17NO3S (387.45): requires C,
71.30; H,4.42; N, 3.62. Found C, 71.19; H, 4.33; N, 3.51.
1-((4-Chlorophenyl)(propylthio)methyl)naphthalen-2-ol (Table 2, entry 7): Pale
yellow solid, mp 88–91 °C; 1H NMR (400 MHz, CDCl3): d 0.85 (t, J = 7.2 Hz, 3H),
1.46–1.56 (m, 2H), 2.31–2.38 (m, 1H), 2.43–2.50 (m, 1H), 6.15 (s, 1H), 7.15 (t,
J = 8.4 Hz, 3H), 7.23–7.27 (m, 3H), 7.35 (t, J = 7.6 Hz, 1H), 7.68–7.73 (m, 3H), 8.94
(s, 1H, OH); 13C NMR (100 MHz, CDCl3): d 13.5, 22.4, 34.7, 45.9, 113.3, 120.3,
121.6, 123.5, 127.3, 129.1 (2C), 129.3, 129.5, 129.8 (2C), 130.7, 133.2, 133.6,
137.3, 155.3; IR (KBr, cmÀ1
: 3436 (OH); Anal. Calcd C20H19ClOS (342.88):
requires C, 70.06; H, 5.59. Found C, 69.93; H, 5.49.
1-((Benzylthio)(4-chlorophenyl)methyl)naphthalen-2-ol (Table 2, entry 8): pale
yellow semi-solid; 1H NMR (400 MHz, CDCl3): d 3.51 (d, J = 13.2 Hz, 1H), 3.61 (d,
J = 13.6 Hz, 1H), 5.85 (s, 1H), 6.90 (d, J = 6.8 Hz, 2H), 7.07–7.23 (m, 9H), 7.37 (d,
J = 8.4 Hz, 2H), 7.71 (t, J = 8.8 Hz, 2H), 8.81 (s, 1H, OH); 13C NMR (100 MHz,
CDCl3): d 37.0, 45.2, 112.8, 120.2, 121.9, 123.5, 127.1, 127.6, 128.8 (2C), 129.0
(2C), 129.1, 129.2 (2C), 129.5, 129.9 (2C), 130.8, 133.1, 133.6, 136.5, 136.8,
155.3; IR (KBr, cmÀ1: 3430 (OH); Anal. Calcd C24H19ClOS (390.93): requires C,
73.74; H, 4.90. Found C, 73.61; H, 4.99.
1-((4-Chlorophenyl)(phenylthio)methyl)naphthalen-2-ol (Table 2, entry 9): pale
yellow semi-solid; 1H NMR (400 MHz, CDCl3): d 6.56 (s, 1H), 7.12–7.15 (m, 3H),
7.24–7.29 (m, 3H), 7.32–7.38 (m, 4H), 7.42 (d, J = 8.4 Hz, 2H), 7.71 (d, J = 8.8 Hz,
1H), 7.72 (d, J = 8.0 Hz, 1H), 7.74 (d, J = 8.0 Hz, 1H), 8.04 (s, 1H, OH); 13C NMR
(100 MHz, CDCl3): d 50.0, 115.2, 119.9, 122.2, 123.5, 127.2, 128.0, 129.2 (3C),
129.3 (2C), 129.6, 129.9 (3C), 130.6, 131.2 (2C), 132.8, 133.7, 137.2, 154.0; IR
(KBr, cmÀ1: 3450 (OH); Anal. Calcd C23H17ClOS (376.90): requires C, 73.29; H,
4.55. Found C, 73.09; H, 4.46.
1-((4-Bromophenyl)(propylthio)methyl)naphthalen-2-ol (Table 2, entry 10):
pale yellow solid, mp 96–99 °C; 1H NMR (400 MHz, CDCl3):
d 0.93 (t,
J = 7.2 Hz, 3H), 1.54–1.64 (m, 2H), 2.39–2.45 (m, 1H), 2.51–2.58 (m, 1H), 6.21
(s, 1H), 7.21 (d, J = 8.8 Hz, 1H), 7.27 (d, J = 9.2 Hz, 2H), 7.33 (t, J = 7.6 Hz, 1H), 7.39
(d, J = 8.8 Hz, 2H), 7.43 (d, J = 6.8 Hz, 1H), 7.80 (d, J = 8.8 Hz, 3H), 9.01 (s, 1H, OH);
13C NMR (100 MHz, CDCl3): d 13.6, 22.4, 34.8, 46.0, 113.2, 120.4, 121.6, 121.8,
123.5, 127.3, 129.3, 129.5, 130.1 (2C), 130.7, 132.1 (2C), 133.3, 137.9, 155.3; IR
(KBr, cmÀ1: 3423 (OH); Anal. Calcd C20H19BrOS (387.33): requires C, 62.02; H,
4.94. Found C, 61.93; H, 4.99.
1-((4-Bromophenyl)((4-methoxyphenyl)thio)methyl)naphthalen-2-ol (Table 2,
entry 11): pale yellow semi-solid; 1H NMR (400 MHz, CDCl3): d 3.61 (s, 3H), 6.39
(s, 1H), 6.62 (d, J = 8.8 Hz, 2H), 7.16 (d, J = 8.8 Hz, 1H), 7.23 (t, J = 8.0 Hz, 1H),
7.29–7.35 (m, 5H), 7.37–7.40 (m, 2H), 7.66–7.71 (m, 3H), 8.38 (s, 1H, OH); 13C
NMR (100 MHz, CDCl3): d 51.8, 55.3, 114.8 (2C), 115.0, 119.8, 121.7, 122.1,
123.36, 123.45, 127.0, 129.0, 129.5, 130.2 (2C), 130.5, 132.0 (2C), 132.9, 134.7
(2C), 137.7, 154.0, 160.0; IR (KBr, cmÀ1: 3437 (OH); Anal. Calcd C24H19BrO2S
(451.38): requires C, 63.86; H, 4.24. Found C, 63.93; H, 4.30.