Trichloroisocyanuric acid, as an industrial chemical, promotes transthioacetalization of diacetals of 2,2-bis (hydroxymethyl)-1,3-propanediol and cleavage of thioacetals

Article abstract of DOI:10.1080/10426500214566

Trichloroisocyanuric acid has been used as a mild, efficient, and new catalyst for transthioacetalization of diacetals of 2,2-bis (hydroxymethyl)-1,3-propanediol in CH₂Cl₂ at room temperature. A clean, easy, and general method for efficient deprotection of thioacetals to their corresponding carbonyl compounds using trichloroisocyanuric acid/silica gel and water system also is described.

Full text of DOI:10.1080/10426500214566

Phosphorus, Sulfur, and Silicon and the Related Elements
ISSN: 1042-6507 (Print) 1563-5325 (Online) Journal homepage: http://www.tandfonline.com/loi/gpss20
Trichloroisocyanuric Acid, as an Industrial
Chemical, Promotes Transthioacetalization
of Diacetals of 2,2-Bis (Hydroxymethyl)-1,3-
propanediol and Cleavage of Thioacetals
Habib Firouzabadi , Nasser Iranpoor & Hassan Hazarkhani
To cite this article: Habib Firouzabadi , Nasser Iranpoor & Hassan Hazarkhani (2002)
Trichloroisocyanuric Acid, as an Industrial Chemical, Promotes Transthioacetalization
of Diacetals of 2,2-Bis (Hydroxymethyl)-1,3-propanediol and Cleavage of Thioacetals,
Phosphorus, Sulfur, and Silicon and the Related Elements, 177:11, 2571-2577, DOI:
10.1080/10426500214566
To link to this article: http://dx.doi.org/10.1080/10426500214566
Published online: 27 Oct 2010.
Submit your article to this journal
Article views: 45
View related articles
Citing articles: 8 View citing articles
Full Terms & Conditions of access and use can be found at
http://www.tandfonline.com/action/journalInformation?journalCode=gpss20
Download by: [Laurentian University]
Date: 30 May 2016, At: 08:05

Phosphorus, Sulfur and Silicon, 2002, Vol. 177:2571–2577
Copyright �C 2002 Taylor & Francis
1
042-6507/02 $12.00 + .00
DOI: 10.1080/10426500290110784
TRICHLOROISOCYANURIC ACID, AS AN
INDUSTRIAL CHEMICAL, PROMOTES
TRANSTHIOACETALIZATION OF DIACETALS OF
2
,2-BIS (HYDROXYMETHYL)-1,3-PROPANEDIOL
AND CLEAVAGE OF THIOACETALS
Habib Firouzabadi, Nasser Iranpoor, and Hassan Hazarkhani
Department of Chemistry, College of Sciences,
Shiraz University, Shiraz 71454, Iran
(Received February 26, 2002; accepted May 14, 2002)
Trichloroisocyanuric acid has been used as a mild, efficient,
and new catalyst for transthioacetalization of diacetals of 2,2-bis
(
hydroxymethyl)-1,3-propanediol in CH Cl2 at room temperature. A
2
clean, easy, and general method for efficient deprotection of thioacetals
to their corresponding carbonyl compounds using trichloroisocyanuric
acid/silica gel and water system also is described.
Keywords: Deprotection; diacetals of 2,2-bis (hydroxymethyl)-1,3-
propanediol; transthioacetalization; thioacetals; trichloroisocyanuric
acid
INTRODUCTION
Protection of carbonyl compounds as dithioacetals (1,3-dithiolanes, 1,3-
dithianes, and acyclic thioacetals) is an indispensable part of the syn-
thesis of many polyfunctional molecules. Moreover, thioacetals often
serve as precursors of acyl anion equivalents displaying reactivity
umpolung and masked methylene function.1 Although, they have
been prepared generally by condensation of carbonyl compounds with
dithiols, transthioacetalization has gained attention as the method of
� 4
5
� 10
choice for this purpose.
Conversion of thioacetals under mild reaction conditions into car-
bonyl compounds also is the most frequently used procedure in multi
The authors are grateful to National Research Council of I. R. for Grant No. 464 and
Shiraz University Research Council for the partial support of this work.
Address correspondence to H. Firouzabadi, Department of Chemistry, College of Sci-
ences, Shiraz University, Shiraz, 71454 Iran. E-mail: firouzabadi@chem.susc.ac.ir
2
571

2
572
H. Firouzabadi et al.
step organic synthesis.1 Recently, we have introduced some mild, effi-
� 4
cient, and chemoselective catalysts for thioacetalization and transthio-
1
1� 13
acetalization reactions.
In this article we report transthioacetal-
ization of diacetals of 2,2-bis (hydroxymethyl)-1,3-propanediol and
cleavage of thioacetals with trichloroisocyanuric acid (TCIA) under mild
reaction conditions.
RESULTS AND DISCUSSION
(
(
a) Transthioacetalization of Diacetals of 2,2-Bis
hydroxymethyl)-1,3-propanediol Catalyzed
by Trichloroisocyanuric Acid (TCIA, 1)
Acetals are one of the most useful and versatile protecting groups
for carbonyl functions and the most popular ones are 1,3-dioxolanes
and 1,3-dioxanes, because of their relative stabilities.1
4� 16
These com-
pounds are usually liquid and their purifications and their handlings
are difficult. In recent years, attention has been paid to the synthesis
of diacetals of 2,2-bis (hydroxymethyl)-1,3-propanediol. These are
crystalline compounds with sharp melting points,1
7� 21
therefore their
isolation and identifications are an easy process. Direct transformation
of these substances to other classes of compounds has not yet been
reported in the literature.
Literature survey shows that TCIA, a cheap industrial chemical has
found little applications in functional group transformation.2
2� 26
Re-
cently, this compound has been used for the conversion of alcohols into
their corresponding alkyl chlorides, oxidation of sulfides into sulfoxides,
and oxidative coupling of thiols and selenols.2
7� 30
Recently we have
used TCIA as a mild catalyst for thioacetalization and transthioac-
3
1
etalization reactions. Now, we report that TCIA catalyzes efficient
conversion of diacetals of 2,2-bis (hydroxymethyl)-1,3-propanediol into
the 1,3-dithiolanes and 1,3-dithianes in CH2Cl2 at room temperature
(
Scheme 1, Table I).
SCHEME 1
As shown in Table I, a wide variety of diacetals with electron-
withdrawing and releasing groups were cleanly and easily converted

Trichloroisocyanuric Acid
2573
TABLE I Transthioacetalization of Acetals of
2,2-Bis(hydroxymethyl)-1,3-propanediol in the Presence of TCIA
with 1,3-Propanedithiol and Ethanedithiol in CH
Temperature
2 2
Cl at Room
Entry
R
n
TCIA (mmol) Time (h) Yield %a
2
2
2
2
2
2
2
2
2
2
2
2
2
a
b
c
d
e
f
g
h
i
Ph
Ph
0
1
0
1
1
1
1
0
1
1
1
0
1
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.3
0.3
0.3
0.3
0.2
0.2
1.5
2
1.5
1.5
1
1
1.5
2
95
94
95
96
94
95
90
92
93
94
92
95
92
4-CH3-C6H4
4-CH3-C6H4
4-CH3O-C6H4
3-CH3O-C6H4
2,4,6-(CH3)3-C6H2
4-Br-C6H4
4-Br-C6H4
4-Cl-C6H4
3-NO2-C6H4
Cinnamyl
Cinnamyl
2
j
k
l
2.5
3.5
1.5
1.5
m
aIsolated yields.
into the 1,3-dithianes and 1,3-dithiolanes under mild reaction condi-
tions in excellent yields.
(
b) Solvent-Free Deprotection of Thioacetals with Silica
Gel/TCIA System
Deprotection of thioacetals into the corresponding parent molecules
is one of the most frequently used procedure in multistep organic
synthesis.1 Literature review shows that conversion of S, S-acetals
� 4
to carbonyl compounds may be achieved by one of two pathways:
4
+
2+
+
(
a) acidic or transition metal ions hydrolysis (such as Ti , Cu , Ag ,
2
+
2+
Hg , Cd ) and (b) oxidative(chemical, photolytic and electrolytic pro-
1� 4
cesses) or alkylative hydrolysis.
Recently reported methods are:
3
2
33
34
35
use of GaCl3/H2O, Bi(NO3), 5H2O/O2, SeO2/AcOH, (PhSeO)2O,
3
+ 36
37
Fe(phen) , SbCl5/aq. NaHCO3, N-fluoro-2,4,6-trimethylpyridinum
3
38
39
triflate/water,
zirconium sulfophenyl phosphonate,
clayan and
clayfen,4
0,41
oxide of nitrogen, natural kaolinitic clay. Some of the
42
43
above methods have its own merits and some drawbacks, such as tox-
icity to the environment, expensive reagent, difficult preparation, and
use of expensive equipments. Very recently preparation and cleavage
4
4
of thioacetals has been reviewed.
On the other hand, trichloroisocyanuric acid (1)/AgNO3/CH3CN/H2O
system has been used for deprotection of thioacetals by Olah and his
coworkers.45 In this procedure large excess of AgNO3 (4.5 equiv.) and

2
574
H. Firouzabadi et al.
1
(4 equiv.) has been used in aqueous CH3CN (75%) for the deprotec-
tion of thioketals. Now we report a cheap, high yielding, and conve-
nient procedure for the deprotection of thioacetals and thioketals to the
corresponding carbonyl compounds with (1)/silica gel system at room
temperature in the absence of solvent (Scheme 2, Table II).
SCHEME 2
By this procedure, the expensive AgNO3 has been omitted and the
amount of trichloroisocyanuric acid (1) has been decreased from 4 to 1.5
equivalents per mole of the substrates. The reaction was completed after
a few minutes by grinding the substrates and 1 with silica gel followed
by the addition of a few drops of H2O. The method shows general appli-
cability for the deprotection of thioacetals and thioketals as well. Ring-
enlargement reactions of thioketals derived from carbonyl compounds
with enolizable hydrogens have not been observed by this method.4
In conclusion, in this study, we introduced a new useful applica-
tion for trichloroisocyanuric acid (TCIA) an industrial chemical that
catalyzes efficiently conversion of diacetals of 2,2-bis (hydroxymethyl)-
6
1
,3-propanediol into the 1,3-dithiolanes and 1,3-dithianes in CH2Cl2 at
room temperature. We have also shown that TCIA as a reagent is able
to effect deprotection of thioacetals and thioketals to the corresponding
carbonyl compounds in the presence of silica gel in the absence of sol-
vent at room temperature. Expensive AgNO3 formerly used by Olah and
his coworkers for this purpose has been eliminated in this procedure
and the amount of trichloroisocyanuric acid has been decreased from
4
to 1.5 equivalents per mole of the substrates. Yields of the isolated
products are usually excellent by these methods.
EXPERIMENTAL
Typical Procedure for Transthioacetalization of Diacetals
of 4-Toluylaldehyde
To a stirred solution of the diacetal of 4-toluylaldehyde (0.75 g,
2
.5 mmol), 1,2-ethanedithol (0.5 ml, 5.5 mmol) in CH2Cl2 (25 ml) and
trichloroisocyanuric acid (0.12 g, 0.5 mmol) was added. After completion

Trichloroisocyanuric Acid
2575
TABLE II Deprotection of Cyclic and Acyclic
Thioacetals and Thioketals
No
R1
R2
n
Yield (%)a,b,47
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
Ph
Ph
H
H
H
H
H
H
H
H
H
H
H
H
H
CH3
CH3
CH3
CH3
CH3
Ph
Ph
CH3
1
2
1
2
1
2
2
2
2
2
1
2
1
2
1
2
2
2
1
2
2
1
2
95
95
92
91
90
92
94
94
90
90
92
92
95
94
96
95
90
92
94
92
94
95
91
4-(CH3)C6H4
4-(CH3)C6H4
4-(CH3O)C6H4
3-(CH3O)C6H4
2-(CH3)C6H4
3-(CH3)C6H4
4-(Br)C6H4
4-(Cl)C6H4
PhCH CH
PhCH CH
Ph(CH3)CH
PhCH2CH2
Ph
1
1
1
1
1
1
1
1
1
1
2
2
2
2
Ph
4-(Cl)C6H4
4-(CH3)C6H4
Ph
Ph
3,4-(CH3O)3C6H3
PhCH2
PhCH2
CH2CH3
CH2CH3
2
4
2
90
2
5
2
89
2
6
2
91
2
2
7
8
-(CH2)5
�
2
2
95
75
Ferrocenyl
CH3
1
a
Isolated yields.
b
Structures are confirmed by IR, H-NMR, 13C-NMR, mp/bp.
of the reaction (1.5 h, TLC) the reaction mixture was quenched with an
aqueous solution of NaOH (10%, 25 ml). Then CH2Cl2 (2 � 15 ml) was
added to the resulting reaction mixture. The organic layer was sepa-
rated, washed with H2O (2 � 100 ml), dried (MgSO4), and filtered. Evap-
oration of the solvent in vacuo gave 2-(4-toluyl)-1,3-dithiolane (0.94 g,

2
576
H. Firouzabadi et al.
9
5
3
6
5%), (white needles) which crystallized from petroleum ether, m.p.
�
1
6–8 C (uncorrected); H-NMR (CDCl3, 250 MHz) � = 2.38 (s, 3H) 3.28–
.45 (m, 4H), 5.60 (s, 1H), 7.11 (d, 2H), 7.40 (d, 2H); 13C-NMR (CDCl3,
3 MHz) � = 21.09, 40.16, 56.11, 127.79, 129.12, 137.10, 137.78 MS (20
+
+
eV) m/z (relative intensity) 196 (M , 68.9), 168 (M - CH2 CH2, 25.4),
1
6
53 (100), 135 (83.6), 91 (57.5), 45 (99.3), CHN analysis: %C (Cald.;
1.17, Found; 61.20), %H (Cald.; 6.16, Found; 6.14).
Typical Procedure for Dethioacetalization of
,2-Diphenyl-1,3-dithiane under Solvent-Free Conditions
2
A mixture of 2,2-diphenyl-1,3-dithiane (0.54 g, 2 mmol), trichloroisocya-
nuric acid (0.69 g, 3 mmol) and silica gel (2 g) was ground in a mortar
for 3 min. Then H2O was added dropwise (10–15 drops) with stirring.
The resulting mixture was continuously extracted in a small continous
extractor with a mixture of n-hexane/EtOAc (5 ml, 5:1). Evaporation of
the solvent in vacuo gave the benzophenone (0.33 g, 92%), white needle
�
46
�
crystals from absolute ethanol m.p. 46–48 C (lit : 47–49 C).
REFERENCES
[
[
1] B. T. Grobel and D. Seebach, Synthesis, 357 (1977).
2] T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis (Wiley:
New York, 1991), 2nd ed., pp. 178–207.
[
[
[
[
3] E. J. Corey and D. Seebach, Angew. Chem., Int. Ed. Engl., 4, 1075, 1077 (1965).
4] D. Seebach, Angew. Chem., Int. Ed. Engl., 8, 639 (1969).
5] J. H. Park and S. Kim, Chem. Lett., 629 (1989).
6] H. Tani, K. Masumoto, T. Inamasu, and H. Suzuki, Tetrahedron Lett., 32, 2039
(1991).
[
[
[
7] V. G. Saraswathy and S. Sankararaman, J. Org. Chem., 59, 4665 (1994).
8] H. Firouzabadi, N. Iranpoor, and B. Karimi, Synlett., 739 (1998).
9] G. K. Jnaneshwara, N. B. Barhate, A. V. H. Sudalai, Deshpande, R. D. Wakharkar,
A. S. Gajare, M. S. Shingare, and R. Sukumar, J. Chem. Soc., Perkin Trans., 1, 965
(1998).
[
[
[
[
10] H. Firouzabadi, N. Iranpoor, and B. Karimi, Synlett., 319 (1999).
11] Firouzabadi, N. Iranpoor, and B. Karimi, Synthesis, 58–60 (1999).
12] H. Firouzabadi, B. Karimi, and S. Eslami, Tetrahedron Lett., 4055–4058 (1999).
13] H. Firouzabadi, N. Iranpoor, H. Hazarkhani, and B. Karimi, J. Org. Chem., 66, 7527
(2001).
[14] H. Firouzabadi, N. Iranpoor, and B. Karimi, Synlett., 321 (1999).
[15] D. J. Kalita, R. Borah, and C. Sarma, Tetrahedron Lett., 39, 4573 (1998).
[16] R. Ballini, G. Bosiva, B. Frullanti, R. Maggi, G. Sartori, and F. Schroer, Tetrahedron
Lett., 39, 1615 (1998).
[17] M. T. S. Jin, T. S. Li, Z. H. Zhang, and Y. J. Yuan, Synth. Commun., 1601 (1999).
[18] C. D. Wang, X. Z. Shi, and R. J. Xie, Synth. Commun., 2517 (1997).
[19] X. Chen, Y. T. Xu, and C. X. Jin, Hecheng Huaxue, 5, 212 (1997).

Trichloroisocyanuric Acid
2577
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
20] E. Bograchov, J. Am. Chem. Soc., 72, 2265 (1950).
21] Y. Peng, G. Song, and X. Qian, Synth. Commun., 31, 3735 (2001).
22] K. Ziegler et al., Justus Liebigs Ann. Chem., 80 (1942).
23] E. C. Juenge, P. L. Spangler, and W. P. Duncan, J. Org. Chem., 31, 3836 (1966).
24] E. C. Juenge and D. A. Beal, Tetrahedron Lett., 5819 (1968).
25] E. C. Juenge, D. A. Beal, and W. P. Duncan, J. Org. Chem., 35, 719 (1970).
26] G. A. Olah, S. C. Narang, and G. F. Salem, Synthesis, 659 (1980).
27] G. A. Hiegel, J. Ramirez, and R. K. Barr, Synth. Commun., 29, 1415 (1999).
28] Z. X. Xiong, N. P. Huang, and P. Zhong, Synth. Commun., 245 (2001).
29] P. Zhong and M. P. Guo, Synth. Commun., 1825 (2001).
30] P. Zhong and M. P. Guo, Synth. Commun., 1507 (2001).
31] H. Firouzabadi, N. Iranpoor, B. Karimi, and H. Hazarkhani, Synlett., 263 (2001).
32] K. Saigo, Y. Hashimoto, and N. Kihara, Chemistry Lett., 831 (1990).
33] N. Komatsu, A. Taniguchi, M. Uda, and H. Suzuki, Chem. Commun., 1847 (1996).
34] S. A. Haroutounian, Synthesis, 39 (1995).
35] N. J. Cussans and S. V. Ley, J. Chem. Soc. Perkin Trans. I, 1654 (1980).
36] M. Schmittel and M. Levis, Synlett., 315 (1996).
37] M. Kamata, H. Otogawa, and E. Hasegawa, Tetrahedron Lett., 32, 7421 (1991).
38] A. S. Kiselyov and L. Strekwski, Tetrahedron, 49, 2151 (1993).
39] M. Curini, M. C. Marcotullio, E. Pisani, and O. Rosati, Synlett., 769 (1997).
40] M. Balogh, A. Corn e´ lis, and P. Laszlo, Tetrahedron Lett., 25, 3313 (1984).
41] H. M. Meshram, G. S. Reddy, and J. S. Yadav, Tetrahedron Lett., 38, 8891 (1997).
42] G. Mehta and R. Uma, Tetrahedron Lett., 37, 1897 (1996).
43] B. P. Bandgar and S. P. Kasture, Green Chemistry, 2, 154 (2000).
44] A. K. Banerjee and M. S. Laya, Russ. Chem Rev., 69, 947 (2000).
45] G. A. Olah, S. C. Narang, and G. F. Salem, Synthesis, 659 (1980).
46] H. Firouzabadi, N. Iranpoor, and B. Karimi, Synlett., 413 (1999).
47] Handbook of Chemistry and Physics, (Chemical Rubber Company, Cleveland, OH,
1
973–74), 5th ed.