Efficient routes for the synthesis of dinaphthosulfide (BINOL Derivatives) and dibenzosulfide aza podands containing ethanolamine

Article abstract of DOI:10.1080/10426500802417059

Four new dinaphthosulfide and dibenzosulfide aza podands were synthesized. The synthesis of these podands was performed under three different reaction conditions: 1) diester, K2CO3, methanol, and RT; 2) diester, ethanolamine, and microwave (MW); and 3) diacid dichloride, ethanolamine, Et3N, CH2Cl2, RT. Two kinds of diester (dinaphthosulfide and dibenzosulfide) were used for the preparation of dihydroxy podands. These dihydroxy podands were reacted with thionyl chloride to afford dichloro podands. The second route gave excellent yields of dihydroxy podands. Dichloro podands are more soluble than dihydroxy podands in conventional solvents such as methanol, chloroform, and acetonitrile.

Full text of DOI:10.1080/10426500802417059

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Phosphorus, Sulfur, and Silicon
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Efficient Routes for the
Synthesis of Dinaphthosulfide
(BINOL Derivatives) and
Dibenzosulfide Aza Podands
Containing Ethanolamine
Esmael Rostami a , Davood Heidaryan b , Hanif
Fattahi b , Abbas Shockravi b , Mehdi Zarei b &
Farokh Rakhshanderu b
a Faculty of Science, Department of Chemistry ,
Bushehr Payamenoor University , Bushehr, Iran
b Faculty of Chemistry , Tarbiat Moallem University
(Teacher Training University) , Tehran, Iran
Published online: 22 Jun 2009.
To cite this article: Esmael Rostami , Davood Heidaryan , Hanif Fattahi , Abbas
Shockravi , Mehdi Zarei & Farokh Rakhshanderu (2009) Efficient Routes for the
Synthesis of Dinaphthosulfide (BINOL Derivatives) and Dibenzosulfide Aza Podands
Containing Ethanolamine, Phosphorus, Sulfur, and Silicon and the Related Elements,
184:7, 1924-1934, DOI: 10.1080/10426500802417059
To link to this article: http://dx.doi.org/10.1080/10426500802417059
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Phosphorus, Sulfur, and Silicon, 184:1924–1934, 2009
Copyright © Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500802417059
Efficient Routes for the Synthesis of Dinaphthosulfide
(BINOL Derivatives) and Dibenzosulfide Aza Podands
Containing Ethanolamine
Esmael Rostami,1 Davood Heidaryan,2 Hanif Fattahi,2
Abbas Shockravi,2 Mehdi Zarei,2 and
Farokh Rakhshanderu2
1Faculty of Science, Department of Chemistry, Bushehr Payamenoor
University, Bushehr, Iran
2Faculty of Chemistry, Tarbiat Moallem University (Teacher Training
University), Tehran, Iran
Four new dinaphthosulfide and dibenzosulfide aza podands were synthesized. The
synthesis of these podands was performed under three different reaction conditions:
1) diester, K CO , methanol, and RT; 2) diester, ethanolamine, and microwave
2
3
(MW); and 3) diacid dichloride, ethanolamine, Et N, CH Cl , RT. Two kinds of
3
2
2
diester (dinaphthosulfide and dibenzosulfide) were used for the preparation of di-
hydroxy podands. These dihydroxy podands were reacted with thionyl chloride
to afford dichloro podands. The second route gave excellent yields of dihydroxy po-
dands. Dichloro podands are more soluble than dihydroxy podands in conventional
solvents such as methanol, chloroform, and acetonitrile.
Keywords Aza podand; 2-chloro ethanolamine, dibenzosulfide; dinaphthosulfide; syn-
thesis
INTRODUCTION
Aza crowns are an important class of host molecules.1 After synthesis
and complexation studies of crown ethers, macrocycles containing aza,
thia, and other functional groups were prepared.2 Their complexation
studies were performed, and they showed strong complexation inter-
action between macrocycles and metal ions.3 Aza podands are another
group of receptors that can be used as important hosts in host–guest
chemistry.4 They have been used as building blocks for the construction
of a large number of supramolecular systems.5
Received 8 March 2008; accepted 18 August 2008.
Address correspondence to Esmael Rostami, Faculty of Science, Department of
Chemistry, Bushehr Payamenoor University, P.O. Box 1698, Bushehr, Iran. E-mail:
esmaelrostami@gmail.com
1924

Dinaphthosulfide and Dibenzosulfide Aza Podands
1925
In this research work, dinaphthosulfide and dibenzosulfide aza po-
dands (5, 10, 11, and 12) containing ethanolamine were synthesized
by three synthetic routes: 1) under microwave irradiation, 2) in room
temperature via diesters (2 and 7), and 3) in room temperature via
diacid chlorides (4 and 9).
RESULTS AND DISCUSSION
Here we report the synthesis of dinaphthosulfide and dibenzosulfide
aza podands (5, 10, 11, and 12). At first we synthesized 1 from the
reaction of p-cresol and sulfur dichloride as reported previously.6 Then
this diphenol (1) was converted to the corresponding diester (2)7 and
diacid (3), respectively (Scheme 1).8 The synthesis of diester (2) was
performed efficiently in MeCN:DMF (10:1) as a binary solvent mixture;
without DMF this reaction did not take place. Diacid (3) was prepared
at room temperature from a mixture of water, methanol, and KOH. The
resulting diacid (3) was converted to diacid dichloride (4) in the presence
of oxalyl chloride in dichloromethane containing catalytic amounts of
DMF.9 This dichloride was reacted with ethanolamine in CH2Cl2 in
the presence of triethylamine at 0◦C (and then r.t.) to give 5 as benzo
dihydroxy podand (Scheme 1).10
Dinaphthosulfide monomer (6, Figure 1) was synthesized based on
the reported procedure6 from the reaction of 2-naphthol and sulfur
dichloride. This dinaphthol (6) was reacted with methylchloroacetate
in acetonitrile in the presence of DMF (10:1) to give the correspond-
ing diester (7),7 and this diester hydrolyzed to diacid (8) in the pres-
ence of methanol and KOH (10%) at room temperature.8 The resulting
diacid (8) was converted to diacid dichloride (9) in the presence of oxa-
lyl chloride and catalytic amounts of DMF in dichloromethane.9 Diacid
dichloride (9) was reacted with ethanolamine in CH2Cl2 in the pres-
ence of triethylamine to afford 10 as naphthalene dihydroxy podand
(Scheme 2).10
Optimization of the above procedure for the synthesis of podands
(5 and 10) was performed as follows. First, the synthesis of diacid
dichlorides (4 and 9) was examined in two reaction conditions: 1) in the
presence of thionyl chloride, and 2) in the presence of oxalyl chloride.
Then these compounds (4 and 9) were reacted with ethanolamine in
CH2Cl2 in the presence of triethylamine (as a standard procedure).
The better yields were obtained when oxalyl chloride was used for the
synthesis of diacid dichlorides. Alternatively, the synthesis of these
compounds was performed via diacides in the presence of DCC and
DMAP in CH2Cl2 in the presence of Et3N, but the yields were lower

1926
E. Rostami et al.
SCHEME 1 Synthesis of dibenzosulfide diaza podand (5) via acid chloride
(Route [A]).
than those of the above route (because of the formation of byproducts).
In conclusion, the key step for the synthesis of these podands (5 and
10) via the above route is the synthesis of diacid dichlorides (4 and
9).
The synthesis of these podands was examined in the other
two reaction conditions from the corresponding diesters (2 and 7)
(Scheme 3). The reaction of diesters and ethanolamine without solvent
(ethanolamine as reagent and solvent) under microwave irradiation
led to the corresponding dihydroxy podands (5 and 10) in lower yields.

Dinaphthosulfide and Dibenzosulfide Aza Podands
1927
OH
OH
S
OH
OH
BINOL
6
FIGURE 1 The structures of 6 and BINOL.
SCHEME 2 Synthesis of dinaphthosulfide diaza podand (10) via acid chloride
(Route [A]).

1928
E. Rostami et al.
SCHEME 3 Synthesis of podands (5 and 10) via diesters (2 and 7).
This reaction was examined in methanol, ethanol, and ethylene glycol
as solvent (in different equivalents of ethanolamine), and finally the
use of ethanolamine as reagent and solvent, in various times and pow-
ers. The best results were obtained when ethanolamine was used as
reagent and solvent in 3 × 30 sec in 700 W.
The synthesis of these podands in room temperature from diesters
was an efficient route for the synthesis of these compounds. In this
reaction, dihydroxy podands (5 and 10) were obtained from the reaction
of diesters (2 and 7) and ethanolamine in dry methanol in the presence
of potassium carbonate at room temperature in excellent yields.
This reaction was performed in the presence of catalytic or stoichio-
metric amounts of Et3N, K2CO3, para-toluene sulfonic acid (p-TsOH),
and Cu(OAc)2 (OAc is the acetate group) in dry methanol. The best re-
sults were obtained in the presence of stoichiometric amounts of K2CO3
at room temperature for 24 h.
Comparison of the routes and yields reported in the synthesis of
these podands (5 and 10) shows that the synthesis via diesters (2 and
7) at room temperature in the presence of K2CO3 ([B]) is the best
procedure, because of the formation of byproducts in the other two
routes ([A] and [C]). The results that were obtained via three general

Dinaphthosulfide and Dibenzosulfide Aza Podands
1929
SCHEME 4 Synthesis of chloropodands (11 and 12).
procedures for the synthesis of hydroxyl podands (5 and 10) show that
[B] is the most efficient route, [C] is the second most efficient, and [A]
is the least important route (Table I).
These two podands (5 and 10) were reacted with thionyl chloride in
refluxing chloroform to afford dichloro derivatives (11 and 12) in high
yields (Scheme 4).[11] The solubilities of these podands were examined
in a series of solvents (Table II). According to these solubilities, the
dichloro derivatives (11 and 12) are more soluble than their dihydroxy
derivatives (5 and 10) in conventional solvents, and show that for ap-
plication of these podands the dichloro derivatives (11 and 12) are more
efficient than dihydroxy derivatives (5 and 10).
TABLE I Comparison of the Yields and Methods
Entry
Podand
Method
Yield (%)
1
2
3
4
5
6
5
10
5
10
5
[A]
[A]
[B]
[B]
[C]
[C]
36
45
91
94
71
67
10

1930
E. Rostami et al.
TABLE II II Solubilitya of Podands
Entry
CHCl3
MeOH DMF NMP
DMAc DMSO MeCN Acetone
b
c
d
5
–
+
++
++
++
++
++
++
++
++
++
++
++
++
++
++
++
++
–
–
–
–
10
11
12
–
+
++
++
++
++
++
++
++
++
aSolubility measured at concentration of 0.05 g/mL.
bInsoluble.
cSoluble after heating.
dSoluble in room temperature.
EXPERIMENTAL
The reactions were carried out in an efficient hood. All the materials
were purchased from Merck, Fluka, and Aldrich chemical companies.
The compounds 2, 3, 7, and 8 were prepared previously via different
reaction conditions and routes.12 The new experimental procedures for
the synthesis of these compounds (2, 3, 7, and 8) are reported in the
References and Notes section.13–16 Chloroform, dichloromethane, ace-
tonitrile, and methanol were distilled and stored over a molecular sieve.
DMF was distilled over a molecular sieve under reduced pressure and
stored over a molecular sieve. The melting points (uncorrected) were
measured with an Electrothermal engineering LTD 9100 apparatus.
Elemental analyses were performed by a CHN-O- Rapid Heraeus ele-
mental analyzer. IR spectra were measured on a Perkin-Elmer model
1
543. The H NMR and 13C NMR spectra were obtained using Bruker
Avance DRX 500 and Bruker Avance DPX 300 MHz apparatus. The
mass spectra were obtained with Shimadzu GC-MS-QP 1100 EX model.
Microwave apparatus was a domestic microwave oven.
General Procedure for the Synthesis of Podands (5 and 10) via
Acid Chlorides (4 and 9) [A]
Diacid (3 or 8, 1 mmol), oxalyl chloride (2 mmol, 0.17 mL), and catalytic
amounts of dimethyl formamide (DMF, 2 drops) in dichloromethane
(dry, 50 mL) were stirred at 0◦C for 20 min and then at room tem-
perature overnight. After the appearance of a clear yellow solution,
the reaction mixture was filtered and the solvent was evaporated to
afford a yellow solid. This product was used in another step without
further purification. To a reaction mixture of ethanolamine (2 mmol,
0.12 mL) and triethylamine (2 mmol, 0.28 mL) in acetonitrile (50 mL)
at 0◦C, the above diacid chloride in acetonitrile (20 mL) was added

Dinaphthosulfide and Dibenzosulfide Aza Podands
1931
dropwise. After stirring overnight under N2, water was added, and the
mixture was extracted with dichloromethane (3 × 50 mL). The com-
bined organic layers were washed with HCl (10%, 2 × 50 mL) and dried
(Na2SO4) and evaporated to afford a white solid, which was purified by
recrystallization in ethanol to obtain 5 and 10 in 36% and 45% yields,
respectively.
2,2ꢀ-Thio Bis(4-methyl-(1-oxa-3-oxo-4-aza-6-hydroxyhexyl)-
benzene) (5)
White powder, mp = 127–128◦C; IR (KBr): 3396, 3317, 2981, 2950,
2933, 2878, 1660, 1653, 1545, 1492, 1422, 1374, 1293, 1246, 1077, 1061,
814, 561 cm−1; 1H NMR (300 MHz, DMSO-d6) δ: 2.15 (3H, s), 3.15 (2H,
q), 3.34–3.40 (2H, m), 4.49 (2H, s), 4.72 (1H, t, J = 6Hz), 6.87 (1H,
d, J = 3Hz), 6.90 (1H, d, J = 9 Hz), 7.06 (1H, dd, J = 3, 9 Hz), 7.54
(1H, t, J = 6 Hz) ppm; 13C NMR (75 MHz, DMSO-d6) δ: 167.4, 153.9,
131.7, 131.1, 129.1, 121.7, 113.2, 67.8, 59.6, 41.1, 20.0 ppm; Elemental
analysis calculated for C22H30N2O6S: C, 58.65; H, 6.71; N, 6.22. Found:
C, 58.56; H, 6.78; N, 6.36.
1,1ꢀ-Thio Bis(2-(1-oxa-3-oxo-4-aza-6-hydroxyhexyl)-
naphthalene) (10)
White powder, mp = 192–193◦C; IR (KBr): 3403, 3329, 2951, 2886,
1653, 1622, 1539, 1504, 1442, 1426, 1347, 1322, 1260, 1233, 1077, 1057,
810, 566 cm−1; 1H NMR (300 MHz, DMSO-d6) δ: 3.11 (4H, q, J = 6, 12
Hz), 3.34 (2H, broad), 4.49 (4H, s), 4.69 (2H, broad), 7.31–7.38 (4H, m),
7.42–7.46 (2H, m), 7.60 (2H, t), 7.83–7.90 (4H, two dubletes), 8.44 (2H,
d) ppm; 13C NMR (75 MHz, DMSO-d6) δ: 167.5, 156.0, 134.1, 130.1,
129.5, 128.4, 127.2, 124.6, 124.1, 117.2, 115.4, 68.4, 59.6, 41.1 ppm; MS
[EI] m/z: 458 (9%), 316 (42%), 299 (100%), 244 (44%), 186 (17%), 157
(14%), 143 (15%), 115 (5%), 102 (7%); Elemental analysis calculated for
C28H28N2O6S: C, 64.60; H, 5.42; N, 5.38. Found: C, 64.52; H, 5.45; N,
5.43.
General Procedure for the Synthesis of Podands (5 and 10) via
Diesters (2 and 7) in Room Temperature [B]
Potassium carbonate (0.56 g, 4 mmol) was added to a solution of di-
esters (2 or 7, 2 mmol) and ethanolamine (4 mmol, 0.24 mL) in dry
methanol (75 mL). The resulting mixture was stirred at room temper-
ature for 24 h. After completion of the reaction (monitored by TLC),
water was added and the resulting mixture was extracted with chloro-
form, dried (Na2SO4), and evaporated to give the crude product. After

1932
E. Rostami et al.
recrystallization from ethanol, 5 and 10 were obtained in 91% and 94%
yields, respectively.
General Procedure for the Synthesis of Podands (5 and 10) via
Diesters (2 and 7) Under Microwave (MW) Irradiation [C]
To diester (2 or 7, 2 mmol), ethanolamine (10 mmol, excess) was added.
This mixture was irradiated under microwave (3 × 30 sec) at a power
of 700 W to completion (monitored by TLC). After completion, water
was added (100 mL) to the mixture, and the resulting suspension was
extracted with CH2Cl2 (3 × 50 mL), the combined organic layers were
dried (Na2SO4) and evaporated to afford crude products. After recrys-
tallization from ethanol, 5 and 10 were obtained in 71% and 67% yields,
respectively.
General Procedure for the Reaction of Podands (5 and 10) with
Thionyl Chloride [D]
To podands (5 or 10, 1 mmol) in dry chloroform (100 mL), thionyl chlo-
ride (2 mmol, 0.15 mL) was added after stirring at room temperature
for 30 min. The mixture was refluxed for 4 h. After completion of the
reaction (monitored by TLC), water was added, and the mixture was
extracted with chloroform (3 × 50 mL). The combined chloroform layers
were dried (Na2SO4) and evaporated to afford a crude product, which
was recrystallized in ethanol to give 11 and 12 in 94% and 96% yields,
respectively.
2,2ꢀ-Thio Bis(4-methyl-(1-oxa-3-oxo-4-aza-6-chlorohexyl)-
benzene) (11)
White powder; mp = 98–99◦C; IR (KBr): 3409, 3286, 2984, 2976,
2879, 1676, 1631, 1538, 1507, 1443, 1328, 1255, 1216, 1085, 1053, 811,
1
564 cm−1; H NMR (300 MHz, DMSO-d6) δ: 2.15 (6H, s), 3.42 (4H, q),
3.65 (4H, t), 4.53 (4H, s), 6.85- 6.90 (2H, m), 6.92–6.96 (2H, m), 7.03–
7.14 (2H, m), 7.84–7.88 (2H, m) ppm; 13C NMR (75 MHz, DMSO-d6)
δ: 167.8, 153.8, 131.9, 131.7, 131.2, 121.8, 113.3, 67.8, 42.3, 37.9, 20.1,
20.0 ppm; Elemental analysis calculated for C22H26Cl2N2O4S: C, 54.43;
H, 5.40; N, 5.77. Found: C, 54.35; H, 5.49; N, 5.86.
1,1ꢀ-Thio Bis(2-(1-oxa-3-oxo-4-aza-6-chlorohexyl)-
naphthalene) (12)
White powder, mp = 166–167◦C; IR (KBr): 3410, 3295, 3095, 2996,
2952, 1681, 1626, 1574, 1532, 1510, 1474, 1325, 1243, 1096, 810, 755

Dinaphthosulfide and Dibenzosulfide Aza Podands
1933
1
cm−1; H NMR (300 MHz, CDCl3) δ: 3.03 (4H, q), 3.22 (4H, t, J = 6.3
Hz), 4.34 (4H, s), 6.09 (2H, broad), 7.12 (2H, d, J = 9 Hz), 7.47 (2H, ddd,
J = 0.9, 7.5, 7.6 Hz), 7.60 (2H, ddd, J = 1.2, 7.8, 7.9 Hz), 7.85 (4H, t),
8.70 (2H, d, J = 8.7 Hz) ppm; 13C NMR (75 MHz, CDCl3) δ: 167.6, 154.9,
134.9, 130.1, 130.0, 129.9, 129.8, 128.6, 128.2, 119.8, 115.2, 69.9, 42.6,
41.2 ppm; MS [EI] m/z: 556 (14%), 317 (19%), 316 (38%), 298 (28%),
255 (31%), 225 (100%), 187 (12%), 186 (20%), 158 (18%), 151 (23%), 144
(17%), 115 (18%); Elemental analysis calculated for C28H26Cl2N2O4S:
C, 60.32; H, 4.70; N, 5.02. Found: C, 60.21; H, 4.74; N, 5.13.
REFERENCES
[1] V. Csokai, M. Kadar, D. L. H. Mai, O. Varga, K. Toth, M. Kubinyi, A. Grun, and I.
Bitter, Tetrahedron, 64, 1058 (2008).
[2] (a) S. Y. Lee, K. Park, S. S. Lee, Inorg. Chem. Commun., 11, 307 (2008); (b) J. D.
Chartres, L. F. Lindoy, and G. V. Meehan, Tetrahedron, 62, 4173 (2006); (c) L. F.
Lindoy, J. Iran. Chem. Soc., 1, 1 (2004).
[3] S. Kang, N. Kim, and J. H. Jeong, Inorg. Chim. Acta, 361, 349 (2008); (b) C. Tu, K.
Surowiec, J. Gega, D. W. Purkiss, and R. A. Bartsch, Tetrahedron, 64, 1187 (2008).
[4] A. P. Davis, Coord. Chem. Rev., 250, 2939 (2006).
[5] Y. Zhao, Y. Tang, W. Liu, N. Tang, and M. Tan, Spectrochim. Acta, Part A, 65, 372
(2006).
[6] (a) W. S. Gump and J. C. Vitucci, J. Am. Chem. Soc., 67, 238 (1945); (b) M. Gazdar
and S. Smiles, J. Chem. Soc., 97, 2248 (1910); (c) J. W. Airan and S. V. Shah, Chem.
Abstr., 35, 6950 (1940).
[7] M. Sibrian-Vazquez, T. J. Jensen, R. P. Hammer, and M. G. H. Vicente, J. Med.
Chem., 49, 1364 (2006).
[8] (a) J. Byron, G. W. Gray, and R. C. Wilson, J. Chem. Soc. (C), 841 (1996); (b) S. E.
Diamond, B. Grant, G. M. Tom, and H. Taube, Tetrahedron Lett., 4025 (1974).
[9] P. Tecilla, S. Chang, and A. D. Hamilton, J. Am. Chem. Soc., 112, 9586 (1990).
[10] J. Y. Lee, S. K. Kim, J. H. Jung, and J. S. Kim, J. Org. Chem., 70, 1463 (2005).
[11] S. M. Seyedi, M. Shadkam, and A. Ziafati, J. Incl. Phenom. and Macrocyclic Chem.,
180, 1953 (2005).
[12] (a) A. Shockravi, S. T. Bavili, E. Rostami, A. Yousefi, A. Dehjurian, and R. Tohidi, J.
Incl. Phenom. Macrocyclic Chem., 49, 163 (2004); (b) A. Shockravi, S. Mehdipour-
Ataei, E. Abouzari-Lotf, and A. Yousefi, Eur. Polym. J., 42, 133 (2006).
[13] Synthesis of 2,2ꢀ- thio bis (methyl-(4-methyl phenoxy acetate)) (2): To a mixture
of 1 (4.75 g, 19 mmol), potassium carbonate (5.24 g, 38 mmol), and potassium
iodide (catalytic) in acetonitrile (100 mL) and DMF (10 mL) at room temperature,
methylchloroacetate (3.35 mL, 38 mmol) was added. Then the reaction mixture was
stirred at room temperature for 24 h. After completion of the reaction (monitored
by TLC), water was added to the mixture and extracted with chloroform (3 ×
50 mL), and the combined chloroform layers were washed with sodium hydroxid
solution (10%, 50mL), dried (Na2SO4), and evaporated to afford a precipitate that
recrystallized from ethanol to give pure 2 in 95% yield, mp = 98–100◦C, IR (KBr):
2960, 2940, 1760, 1480, 1440, 1280, 1250, 1200, 1150, 1080, 990, 800 cm−1;1H
NMR (60 MHz, CDCl3) δ: 2.2 (6H, s), 3.7 (6H, s), 4.65 (4H, s), 6.8–7.2 (6H, m) ppm;
Elemental analysis calculated for C20H22O6S: C, 61.52; H, 5.68. Found C, 61.58; H,
5.56.

1934
E. Rostami et al.
[14] Synthesis of 2,2ꢀ-thio bis(4-methyl phenoxy acetic acid) (3): To a solution of methanol
(70 mL) and potassium hydroxide (10%, 7mL), 2 was added and the resulting mix-
ture was stirred at room temperature for 12 h. After completion of the reaction
(monitored by TLC), water was added and acidified with HCl (10%, 30 mL). The
resulting white precipitate was filtered and washed with water. The crude prod-
uct was recrystallized in ethanol/water to obtain 3 in 92% yield, mp = 178–180◦C,
IR (KBr): 3400–2800, 3040, 2920, 1745, 1720, 1490, 1430, 1280, 1240, 1090, 1040,
810 cm−1;1H NMR (90 MHz, DMSO-d6) δ: 2.1 (6H, s), 4.7 (4H, s), 6.9–7.1 (6H, m)
ppm;13C NMR (62 MHz, DMSO-d6) δ: 170.0, 154.0, 132.1, 130.5, 128.7, 121.7, 112.0,
65.0, 19.9 ppm.; MS (EI) m/z 362 M+, 363 (M+1)+, 364 (M+2)+, 365 (M+3)+, 317,
304, 288, 271, 257, 244, 228, 214, 201, 195, 184, 151, 121, 105, 91, 77.
[15] Synthesis of 1,1ꢀ-thio bis-(2-naphthoxy (2-methyl acetate)) (7): Similar to the prepa-
ration of 2, this compound (7) was obtained in 91% yield. mp = 126–127◦C; IR (KBr):
3040, 3000, 2970, 1750, 1595, 1500, 1450, 1300, 1250,1200, 1090, 1040, 810, 750
cm−1 1H NMR (300 MHz, acetone-d6) δ: 3.65 (6H, s), 4.65 (4H, s), 7.09 (2H, ddd, J
;
= 8.46, J = 6.94, J = 1.32 Hz), 7.26 (2H, d, J = 9.05 Hz), 7.35 (2H, ddd, J = 7.98,
J = 6.84, J = 1.11 Hz), 7.81 (2H, d, J = 7.91 Hz), 7.83 (2H, d, J = 9.02 Hz), 8.69
(2H, d, J = 8.59 Hz) ppm; Elemental analysis calculated for C26H22O6S: C, 67.52;
H, 4.79. Found: C, 67.45; H, 4.67.
[16] Synthesis of 1,1ꢀ-thio bis-(2-naphthoxy acetic acid) (8): Similar to the above pro-
cedure for the preparation of 3, this diacid (8) was obtained in 87% yield, mp =
259–261◦C, IR (KBr): 3210–2420 (broad), 1720,1710, 1620, 1580, 1500, 1460, 1430,
1350, 1290, 1275, 1250, 1215, 1150, 1100, 1020, 950, 910, 800, 775, 740 cm−1 1H
;
NMR (500 MHz, DMSO-d6) δ: 4.13 (4H, s), 6.77 (2H, d, J = 8.95 Hz), 6.97 (2H, dd,
J = 7.41, J = 7.45 Hz), 7.09 (2H, dd, J = 8.0, J = 7.4 Hz), 7.39 (4H, d, J = 8.65
Hz), 830 (2H, d, J = 8.55 Hz) ppm; 13C NMR (125 MHz, DMSO-d6) δ: 66.6, 115.7,
119.1, 124.3, 125.9, 127.1, 128.3, 129.6, 130.0, 135.3, 156.5, 170.8 ppm; Elemental
analysis calculated for C24H18O6S: C, 66.35; H, 4.18. Found: C, 66.29; H, 4.07.