An Improved Iodine(III) Mediated Method for Thiocyanation of 2-Arylindan-1,3-diones, Phenols, and Anilines

Article abstract of DOI:10.1081/SCC-120026343

An improved method for thiocyanation of 2-arylindan- 1,3-diones, phenols, and anilines using a reagent combination of (dichloroido)-benzene and potassium thiocyanate in dry dichloromethane is described.

Full text of DOI:10.1081/SCC-120026343

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An Improved Iodine(III) Mediated Method for
Thiocyanation of 2-Arylindan-1,3-diones, Phenols, and
Anilines
Om Prakash a , Harpreet Kaur a , Rashmi Pundeer a , R. S. Dhillon b & Shiv P. Singh a
a Department of Chemistry, Kurukshetra University, Kurukshetra, India
b Department of Chemistry, Punjab Agricultural University, Ludhiana, India
Published online: 16 Aug 2006.
To cite this article: Om Prakash , Harpreet Kaur , Rashmi Pundeer , R. S. Dhillon & Shiv P. Singh (2003): An Improved
Iodine(III) Mediated Method for Thiocyanation of 2-Arylindan-1,3-diones, Phenols, and Anilines, Synthetic Communications: An
International Journal for Rapid Communication of Synthetic Organic Chemistry, 33:23, 4037-4042
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SYNTHETIC COMMUNICATIONSÕ
Vol. 33, No. 23, pp. 4037–4042, 2003
An Improved Iodine(III) Mediated Method for
Thiocyanation of 2-Arylindan-1,3-diones,
Phenols, and Anilines
1
1
Om Prakash,1, Harpreet Kaur, Rashmi Pundeer,
*
R. S. Dhillon,2 and Shiv P. Singh1
1Department of Chemistry, Kurukshetra University,
Kurukshetra, India
2Department of Chemistry,
Punjab Agricultural University, Ludhiana, India
ABSTRACT
An improved method for thiocyanation of 2-arylindan-1,3-diones,
phenols, and anilines using a reagent combination of (dichloroiodo)-
benzene and potassium thiocyanate in dry dichloromethane is
described.
Key Words: Thiocyanation; Organohypervalent iodine; (Dichloro-
iodo) benzene; Potassium thiocyanate.
*Correspondence: Om Prakash, Department of Chemistry, Kurukshetra
University, Kurukshetra-136119, India; E-mail: oprakash50@sify.com.
4037
DOI: 10.1081/SCC-120026343
Copyright & 2003 by Marcel Dekker, Inc.
0039-7911 (Print); 1532-2432 (Online)
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4038
Prakash et al.
There is considerable recent interest in the use of organohypervalent
iodine(III) compounds as oxidizing agents in organic synthesis.[1–3] We
have recently reported that a combination reagent (dichloroiodo)benzene
and lead thiocyanate in dichloromethane (system i ) constitutes a very
efficient reagent system for a-thiocyanation of carbonyl and b-dicarbonyl
compounds.[2] The same reagent system has also been employed for the
thiocyanation of phenols and anilines.[4]
In an effort to improve the experimental procedure and to avoid the
use of toxic and expensive lead thiocyanate, we have now used an alter-
native reagent system, i.e., (dichloroiodo)benzene-potassium thiocyanate
in dichloromethane (system ii) to effect these thiocyanations.
We, first carried out the reaction with 2-phenylindan-1,3-dione (1a) as
a typical example of a-substituted b-dicarbonyl compounds, to afford 2-
phenyl-2-thiocyanatoindan-1,3-dione (2a) in 85% yield. Other
2-arylindan-1,3-diones (1b–e) also reacted smoothly with system ii to
give 2-aryl-2-thiocyanatoindan-1,3-diones (2b–e). The scope of this
reagent system was further extended for thiocyanation of phenols and
anilines. Only representative cases were investigated and it was found that
system ii efficiently converts phenol (3a), catechol (3b), a-naphthol
(7a), aniline (5a), substituted anilines (5b–d), a-naphthylamine (7b) to
the corresponding p-thiocyanato derivatives 4a, 4b, 6a, 6b–d, 8a, 8b
respectively (Sch. 1). The yields using system ii are comparable with
O
O
OH
O
O
OH
R
R
R
System ii
System ii
R
SCN
SCN
1a-e
2a-e
3a, b
4a, b
a, R = Ph
b, R = p-ClC6H4
a, R = H
b, R = OH
c, R = p-MeC6H d, R = p-OMeC6H4
4
e, R = p-NO2C6H4
X
X
NH2
NH2
R
R
System ii
System ii
R'
R'
SCN
SCN
8a, b
b, X = NH2
7a, b
5a-d
6a-d
a, X = OH
a, R = H, R' = H
b, R = OH, R' = H
c, R = H, R, = OH d, R = COOH, R' = H
Scheme 1.

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Thiocyanation of 2-Arylindan-1,3-diones
4039
those obtained by using system i (Table 1). However, the same approach
involving either systems i or ii, failed to convert other substrates such
as o-phenylenediamine, p-phenylenediamine, and p-aminophenol to
thiocyanato products; rather an inseparable mixture of several products
was obtained.
Interestingly, in certain other cases such as b-naphthol 9 and hydro-
quinone 11, these thiocyanation procedures using systems i/ii lead to
the formation of oxathiole 10 and bisoxathiole 12 as outlined in
Eqs. (1) and (2). Obviously intramolecular cyclization of thiocyanato
or dithiocyanato product might have led to the formation of the
corresponding oxathioles.
Earlier, thiocyanation of phenols and anilines has been reported (i)
by using dichlorourea and NH4SCN,[5] (ii) with Cu (SCN)2,[6] (iii) by
reaction with NaSCN and Br2.[7]
EXPERIMENTAL
Melting points were taken in open capillaries and are uncorrected.
Most of the chemicals were obtained from commercial suppliers.
2-Arylindan-1,3-diones (1a–e) were prepared according to the literature
methods.[8,9]
Table 1. Physical data of thiocyanated products.
Yield (%)
system i
Yield (%)
system ii
Compd. no.
M.p. (ꢀC)
Lit. m.p. (ꢀC)
2a
2b
2c
2d
2e
4a
4b
6a
6b
6c
6d
8a
8b
10
12
124–125
124–125
108–110
139–140
125–127
58
124–126[10]
127[10]
108–110[2]
138–140[10]
126–128[10]
59–60[4]
142[4]
97–98[11]
98[4]
107–109[4]
168–170[5]
113[7]
86
90
90
84
87
78
87
72
80
76
71
65
70
73
72
85
88
88
87
90
72
79
69
86
72
73
69
74
77
75
142
102
100
106
171
110–112
147–148
104
146–147[7]
106[12]
308–309[13]
303

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4040
Prakash et al.
General Procedure for Thiocyanation Using
PhICl2-KSCN/CH2Cl2 (System ii)
To a suspension of potassium thiocyanate (464 mg, 4.8 mmol) in
dichloromethane (10 mL), (dichloroiodo)benzene (656 mg, 2.4 mmol)
was added at 0ꢀC. The mixture was stirred at the same temperature for
15–20 min. Then the substrate (1a–e, 3a–b, 5a–d, 7a–b, 9, 11) (2 mmol) (in
case of 11, 1 mmol) was added to it and stirring was continued for 30 min,
completion of reaction was monitored by TLC. The reaction mixture was
filtered and filtrate was adsorbed on silica gel and chromatographed
using hexane:ethyl acetate (9:1) as eluent. The thiocyanato products
(2a–e, 4a–b, 6a–d, 8a–b) and oxathioles (10 and 12) were identified by
comparison of their melting points (Table 1) and spectral data with those
reported in literature. IR spectra of all the products showed a character-
istic sharp SCN absorption band at ꢁ2160 cmꢂ1
.
O
O
S
SCN
OH
OH
System
i or ii
ð1Þ
ð2Þ
10
9
O
S
O
OH
OH
OH
SCN
System
i or ii
S
NCS
O
OH
O
12
11
System i = PhICl2, Pb(SCN)2/CH2Cl2
ACKNOWLEDGMENTS
We are thankful to DRDO, New Delhi, India for financial assistance
to support this work.

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Thiocyanation of 2-Arylindan-1,3-diones
REFERENCES
4041
1. (a) Moriarity, R.M.; Vaid, R.K.; Koser, G.F. [Hydroxy(organo-
sulfonyloxy)iodo] arenes in organic synthesis. Synlett. 1990, 365–
383; (b) Prakash, O.; Rani, N.; Sharma, P.K. Hypervalent iodine
reagents in the synthesis of heterocyclic compounds. Synlett. 1994,
221–227; (c) Varvoglis, A. Hypervalent Iodine in Organic Synthesis;
Academic Press: London, 1997; (d) Varma, R.S.; Dhaiya, R.; Saini,
R.K. Iodobenzene diacetate on alumina: rapid oxidation of alcohols
to carbonyl compounds in solventless system using microwaves.
Tetrahedron Lett. 1997, 38, 7029–7032; (e) Ochiai, M.; Akibia, K.,
Eds. In Chemistry of Hypervalent Compounds; VCH Publishers:
New York, 1999; Chapter 13, 359–387; (f ) Koser, G.F.
[Hydroxy(tosyloxy)iodo]benzene and closely related iodanes: the
Second Stage of Development. Aldrichimica Acta 2001, 34, 89–
102; (g) Zhdankin, V.V.; Stang, P.J. Recent developments in the
chemistry of polyvalent iodine compounds. Chem. Rev. 2002, 102,
2523–2584.
2. Prakash, O.; Kaur, H.; Batra, H.; Rani, N.; Singh, S.P. a-
Thiocyanation of carbonyl and b-dicarbonyl compounds using
(dichloroiodo)benzene-lead(II) thiocyanate. J. Org. Chem. 2001,
66, 2019–2023.
3. Kita, Y.; Takeda, Y.; Okunu, T.; Egi, M.; Iio, K.; Kawaguchi, K.;
Akai, S. An efficient p-thiocyanation of phenols and naphthols using
a reagent combination of phenyliodine dichloride and lead(II)
thiocyanate. Chem. Pharm. Bull. 1997, 45, 1887–1890.
4. Neu, R. Aryl iododichlorides. Ber. 1939, 72B, 1505–1512.
5. Likhosherstov, M.V.; Petrov, A.A. The preparation of aromatic
thiocyanates with the aid of dichlorourea. J. Gen. Chem. (USSR)
1933, 3, 183–197.
6. Kaufmann, H.P.; Kulchler, K. A further new method for the thio-
cyanation of organic compounds. Ber. 1934, 67B, 944–948.
7. Kaufmann, H.P.; Oehring, W. New method for the thiocyanation of
organic compounds. Ber. 1926, 59B, 187–194.
8. Bailey, D.M.; Johnson, R.E. Reduction of cyclic anhydrides with
sodium borohydride. Versatile lactone synthesis. J. Org. Chem.
1970, 35, 3574–3576.
9. Crabb, T.A.; Roxburgh, C.J.; Newton, R.F. The synthesis and
stereochemistry of derivatives of 1,2,3,4,6,11,12,13,14,14a-decahy-
dropyrido[1,2-b][2]benza zonine. Crystal structure of 1,2,3,4,4a,5,6,
7,7a,12-decahydro-7-phenylisoindolo[1,2-d]quinolizin-1,3-ium tosy-
late. J. Chem. Soc. Perkin Trans I 1989, 2431–2435.

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4042
Prakash et al.
10. Vanags, G.; Gudriniece, E.; Arens, A.; Arens, B. Thiocyanation of
2-aryl-1,3-indandiones. Doklady Akad. Nauk S.S.S.R. 1960, 130
(315); Chem. Abstr. 1960, 54, 10974.
11. Wood, J.L. Substitution and addition reactions of thiocyanogen.
Org. React.; Wiley: New York, 1946; Vol. 6, 240–266.
12. Stevenson, H.A.; Smiles, S. b-Naphtha-1-thioquinone and dehydro-
2-naphthol 1-disulfide. 1930, 1740–1745.
13. Fiedler, H. Jahrg. Preparation of hydroxy-2-oxo and 2-thiono-1,3-
benzoxathioles. 1962, 95, 1771.