Iron-catalyzed tandem reactions of ortho-aminobenzenethiols with isothiocyanates leading to 2-aminobenzoazoles under ligand-and solvent-free conditions

Article abstract of DOI:10.1080/10426507.2010.532841

An efficient route to synthesize a variety of 2-aminobenzoazoles has been discovered. It involves the reaction of ortho-aminobenzenethiols with isothiocyanates via iron-catalyzed tandem addition-annulations process under ligand and solvent free conditions on silica gel surface. Copyright Taylor &Francis Group, LLC.

Full text of DOI:10.1080/10426507.2010.532841

Phosphorus, Sulfur, and Silicon, 186:1782–1789, 2011
Copyright ꢀC Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426507.2010.532841
IRON-CATALYZED TANDEM REACTIONS
OF ORTHO-AMINOBENZENETHIOLS
WITH ISOTHIOCYANATES LEADING TO
2-AMINOBENZOAZOLES UNDER LIGAND-
AND SOLVENT-FREE CONDITIONS
Qiuping Ding,1,2 Banpeng Cao,1 Qin Yang,2 Xianjin Liu,1
and Yiyuan Peng1,2
1College of Chemistry and Chemical Engineering, Jiangxi Normal University,
Nanchang, China
2Key Laboratory of Green Chemistry of Jiangxi Province, Nanchang, China
GRAPHICAL ABSTRACT
NH2
N
S
Fe2(SO4)3 H2O (10 mol %)
DABCO 6H2O (2.0 equiv.)
NHR2
+
R2 NCS
R1
R1
SH
R2 = aryl or alkyl
silica gel, 80 οC
up to 96% yield
Abstract An efficient route to synthesize a variety of 2-aminobenzoazoles has been discovered.
It involves the reaction of ortho-aminobenzenethiols with isothiocyanates via iron-catalyzed
tandem addition-annulations process under ligand and solvent free conditions on silica gel
surface.
Keywords 2-Aminobenzoazoles; iron-catalyzed; isothiocyanate; tandem reaction
INTRODUCTION
2-Aminobenzothiazoles have attracted considerable attention because of their chem-
ical properties and biological activity.1,2 A number of general and efficient methods for
the preparation of this kind of compounds have been developed.3–10 In this area, transi-
tion metal–catalyzed intramolecular cyclization of 2-bromobenzothioureas is one of the
most efficient methods.3–6 For example, Bened´ı et al. first reported the Pd-catalyzed in-
tramolecular cyclization of 2-bromobenzothioureas to form 2-aminobenzothiazoles in the
presence of o-biphenylP(tBu)2 and Cs2CO3.3 Batey and co-workers also reported the same
transformation using ligand-accelerated Cu- or Pd-catalyzed intramolecular cyclizations
Received 23 August 2010; accepted 13 October 2010.
Financial support from the Natural Science Foundation of Jiangxi Educational Committee (GJJ10387),
Jiangxi Province of China (2009GQH0054), Startup Foundation for Doctors of Jiangxi Normal University
(200900266), and National Natural Science Foundation of China (20962010) is gratefully acknowledged.
Address correspondence to Qiuping Ding and Yiyuan Peng, College of Chemistry and Chemical Engi-
neering, Jiangxi Normal University, 99 Ziyang Road, Nanchang 330022, China. E-mail: dqpjxnu@gmail.com;
yypeng@jxnu.edu.cn
1782

SYNTHESIS OF 2-AMINOBENZOAZOLES
1783
O
N
O
N
H
Figure 1 N-(4,5-Dihydrooxazol-2-yl)benzamide.
of ortho-halobenzanilides (using 1,10-phenanthroline or N,Nꢁ-dimethylethylenediamine as
ligands).4,5 Recently, Wang et al. described a practical Cu-catalyzed intramolecular cycliza-
tion process for the synthesis of 2-aminobenzothiazoles employing N-(4,5-dihydrooxazol-
2-yl)benzamide (Figure 1) as a novel and efficient ligand.6
Very recently, a tandem addition/C—S coupling reaction was presented as another
powerful strategy for the construction of the 2-aminobenzothiazole framework.7–10 We
have previously described a novel and efficient method for the preparation of this class of
compounds via copper(I)-catalyzed tandem addition-cyclization reactions of 2-iodoanilines
with isothiocyanates in toluene.7 In addition, on the basis of current criteria of green chem-
istry, we carried out the transformation in the presence of 1,10-phenanthroline as ligand
in water.8 In our work, phase-transfer catalysis (octadecyltrimethylammonium chloride)
was employed as a key additive to enhance the catalytic efficiency. Although there are
many powerful methods to prepare 2-aminobenzothiazoles, most of them are transition
metal–catalyzed using an expensive ligand. Hence, the development of efficient and envi-
ronmental benign approaches under ligand-free conditions is still desirable.
In recent years the use of solid-phase organic synthesis to simplify and improve classi-
cal organic reactions has become a very popular method.11,12 Solvent-free organic synthesis
using silica-supported reagents for the preparation of heterocycles has received considerable
importance as an environmentally benign approach.13 In addition, commercially available
and unmodified silica gel (TLC grade) has been used as an efficient source of solid support
for a variety of organic reactions.14–17 Very recently, we have described a highly efficient
tandem addition-cyclization reactions for 2,4-dihydro-1H-benzo[d][1,3]thiazine promoted
by silica gel.14 Basu et al. reported silica-promoted acylation and alkylation of aromatic
and aliphatic thiols15 and highly selective N-alkylation of amines.16 In continuation of our
work on transition metal–catalyzed tandem annulations for heterocyclic compounds,18–23
we now report a new solid phase synthetic method, which could be used for generation
of 2-aminobenzothiazole libraries. In this article, we describe a practical approach to 2-
aminobenzothiazole based on parallel diversity-oriented synthesis catalyzed by Fe2(SO4)3 ·
H2O under ligand-free conditions on a silica gel surface.
RESULTS AND DISCUSSION
We have chosen 2-aminobenzenethiol 1a and phenyl isothiocyanate 2a as the standard
substrates to optimize the catalysis conditions, including optimization of the Fe salt catalysts
and bases (Table 1). Several Fe salts were evaluated as catalysts for the model reaction. The
results showed that all Fe catalysts investigated could catalyze the reaction and afford the
desired products in good to excellent yields (Table 1, entries 1–6). Among them, Fe2(SO4)3 ·
H2O catalyzed the reaction with the best yield under the employed reaction conditions. On
the other hand in the absence of Fe salt catalyst, the product was obtained only in 48%
yield (Table 1, entry 7). Decreasing the temperature to r.t. slowed down the reaction and
also decreased the yield (Table 1, entry 8). Only 45% of the corresponding product was

1784
Q. DING ET AL.
Table 1 Condition screening for Fe-catalyzed tandem reaction of 2-aminobenzenethiol 1a with phenyl isothio-
cyanate 2a on silica gel surfacea
SH
N
S
NCS
[Fe] 10 mol%
NH
Ph
+
Base, 80 oC
Silica gel
NH2
1a
2a
3a
Entry
Catalyst
Base
Yield (%)b
1
2
3
4
5
6
7
8c
9d
10
11
12
13
14
15
16
FeCl3
DABCO · 6H2O
DABCO · 6H2O
DABCO · 6H2O
DABCO · 6H2O
DABCO · 6H2O
DABCO · 6H2O
DABCO · 6H2O
DABCO · 6H2O
DABCO · 6H2O
–
NaHCO3
Na2CO3
K2CO3
NaOH
DBU
Et3N
70
82
78
83
75
96
48
70
45
70
85
80
80
75
57
38
Fe(NO3)3 · 9H2O
FeSO4 · 7H2O
Fe(NH4)2(SO4)2 · H2O
Fe(acac)3
Fe2(SO4)3 · H2O
–
Fe2(SO4)3 · H2O
Fe2(SO4)3 · H2O
Fe2(SO4)3 · H2O
Fe2(SO4)3 · H2O
Fe2(SO4)3 · H2O
Fe2(SO4)3 · H2O
Fe2(SO4)3 · H2O
Fe2(SO4)3 · H2O
Fe2(SO4)3 · H2O
aReaction conditions: 2-aminobenzenethiol 1a (0.3 mmol), phenyl isothiocyanate 2a (1.5 equiv), [Fe] (10 mol
%), base (2.0 equiv.), silica gel (300 mg), 80◦C, overnight.
bIsolated yield based on 2-aminobenzenethiol 1a.
cr.t., 48 h.
dSilica gel–free conditions.
generated in the absence of silica gel (Table 1, entry 9), which shows the importance of silica
gel in this tandem addition-cyclization reaction. A blank experiment shows that DABCO ·
6H2O can notably enhance the yield of the product (Table 1, entry 10). Subsequently, the
base effect was investigated and DABCO · 6 H2O was found to provide the best result
(Table 1, entry 6) as compared to NaHCO3, Na2CO3, K2CO3, NaOH, DBU, or Et3N
(Table 1, entries 11–16).
The applicability of the Fe-catalyzed tandem addition-cyclization reaction of 2-
aminobenzenethiol 1 with isothiocyanates 2 on silica gel surface was explored under the
optimized conditions [10 mol% Fe2(SO4)3 · H2O as catalyst, 2.0 equiv. DABCO · 6H2O
as base, 1.0 g/mmol silica gel, 80◦C]. As shown in Table 2, the tandem reactions worked
quite well for all the substrates examined, and the desired 2-aminobenzothiazoles were
obtained in moderate to excellent yields. Isothiocyanates with an electron-withdrawing or
electron-donating group attached to the aromatic ring were good substrates in this transfor-
mation. For example, 4-fluorophenyl isothiocyanate 2c reacted with 2-aminobenzenethiol
1a leading to the corresponding product 3c in 83% yield (Table 2, entry 3), and 78% yield
of product 3f was obtained when 4-methylphenyl isothiocyanate 2f was used in the reaction
(Table 2, entry 6). However, isothiocyanates having a strong electron-withdrawing group
(nitro group) display moderate activity (Table 2, entry 2). Alkyl isothiocyanates 2g and
2h were also good partners for this one-pot tandem reaction, giving good yields (Table 2,

SYNTHESIS OF 2-AMINOBENZOAZOLES
1785
Table 2 Iron-catalyzed tandem reaction of 2-aminobenzenethiol 1 with isothiocyanate 2a
NH2
+ R2 NCS
SH
Fe2(SO4)3 H2O (10 mol %)
DABCO 6H2O (2.0 equiv.)
N
S
NHR2
R1
R1
silica gel, 80 οC
1
2
3
Entry
1/R1
2/R2
Product 3
Yield [%]b
1
2
3
4
5
6
7
8
1a/H
1a/H
1a/H
1a/H
1a/H
1a/H
1a/H
1a/H
1b/MeO
1b/MeO
1b/MeO
1c/Br
1c/Br
1c/Br
1d/I
2a/C6H5
3a
3b
3c
3d
3e
3f
3g
3h
3i
3j
3k
3l
3m
3n
3o
3p
3q
96
60
83
70
71
78
88
76
91
71
86
85
75
78
74
72
71
2d/4-NO2C6H4
2c/4-FC6H4
2d/4-ClC6H4
2e/4-MeOC6H4
2f/4-MeC6H4
2g/Et
2h/Cyclohexyl
2a/C6H5
2d/4-ClC6H4
2f/4-MeC6H4
2a/C6H5
2d/4-ClC6H4
2f/4-MeC6H4
2a/C6H5
2d/4-ClC6H4
2f/4-MeC6H4
9
10
11
12
13
14
15
16
17
1d/I
1d/I
aReaction conditions: 2-aminobenzenethiol 1 (0.3 mmol), isothiocyanate 2 (1.5 equiv), Fe2(SO4)3 · H2O
(10 mol %), DABCO · 6H2O (2.0 equiv), silica gel (300 mg), 80◦C, overnight.
bIsolated yield based on 2-aminobenzenethiol 1.
entries 7 and 8). Other substituted 2-aminobenzenethiols 1b–d were also effective in this
kind of reaction and good yields of products were afforded.
In conclusion, wehavesuccessfullydeveloped a novel, facile, and practical methodfor
the synthesis of 2-aminobenzothiazoles from substituted 2-aminobenzenethiols in moderate
to excellent yields using a Fe(III)-catalyzed tandem addition-cyclization. It is noteworthy
that the reaction is carried out under ligand-free conditions in solid phase.
EXPERIMENTAL
All reactions were performed in test tubes. Analytical thin-layer chromatography was
performed using glass plates precoated with 0.25 mm 230–400 mesh silica gel impregnated
with a fluorescent indicator (254 nm). Thin layer chromatography plates were visualized
by exposure to ultraviolet light. Commercially available reagents were used as received.
1H and 13C NMR spectra were recorded with a Bruker AV 400 instrument operating at
400 MHz and 100 MHz, respectively, at 293 K. The chemical shifts are given on the delta
scale (δ) and are referenced to tetramethylsilane (0 ppm). Melting points are uncorrected.
Fe2(SO4)3 · H2O-Catalyzed One-Pot Tandem Reaction of
2-Aminobenzenethiols 1 with Isothiocyanates 2: General Procedure
A mixture of the 2-aminobenzenethiol 1 (0.30 mmol), the isothiocyanate 2 (0.45
mmol, 1.5 equiv.), DABCO · 6 H2O (2.0 equiv), silica gel (300 mg), and Fe2(SO4)3 · H2O

1786
Q. DING ET AL.
(0.03 mmol, 10 mol%) was stirred at 80◦C under N2. After completion of the reaction, as
indicated by TLC, the reaction mixture was cooled to room temperature and then passed
through a small plug of silica to obtain pure 2-aminobenzothizole 3.
N-Phenylbenzo[d]thiazol-2-amine7,9 (3a)
White solid, mp 158–160◦C; 1H NMR (400 MHz, CDCl3): δ = 7.13–7.19 (m, 2H),
7.32 (t, J = 7.2 Hz, 1H), 7.40 (t, J = 8.0 Hz, 2H), 7.50 (d, J = 8.0 Hz, 2H), 7.56 (d, J = 8.0
Hz, 1H), 7.63 (d, J = 7.6 Hz, 1H), 9.0 (br, 1H); 13C NMR (100 MHz, CDCl3): δ = 118.7,
119.9, 120.3, 121.9, 123.9, 125.6, 129.1, 129.3, 129.5, 150.7, 164.5.
N-(4-Nitrophenyl)benzo[d]thiazol-2-amine7 (3b)
Yellow solid, mp 230–231◦C (lit. mp 225–227◦C); 1H NMR (400 MHz, DMSO-d6):
δ = 7.24 (t, J = 7.6 Hz, 1H), 7.39 (t, J = 7.6 Hz, 1H), 7.71 (d, J = 8.0 Hz, 1H), 7.90 (d,
J = 7.6 Hz, 1H), 8.10 (d, J = 9.2 Hz, 2H), 8.27 (d, J = 9.2 Hz, 2H), 11.2 (br, 1H); 13C
NMR (100 MHz, DMSO-d6): δ = 117.6, 120.5, 121.9, 123.7, 125.9, 126.7, 130.8, 141.4,
146.9, 152.0, 161.2.
N-(4-Fluorophenyl)benzo[d]thiazol-2-amine8 (3c)
White solid, mp 216–217◦C; 1H NMR (400 MHz, DMSO-d6): δ = 7.14 (t, J = 7.6
Hz, 1H), 7.19 (t, J = 8.8 Hz, 2H), 7.31 (t, J = 7.6 Hz, 1H), 7.58 (d, J = 8.0 Hz, 1H),
7.77–7.82 (m, 3H), 10.52 (br, 1H); 13C NMR (100 MHz, DMSO-d6): δ = 116.0 (δ, 2JCF
=
22 Hz), 119.7 (δ, 2JCF = 18 Hz), 119.8, 121.5, 122.8, 126.3, 130.3, 137.4, 152.4, 157.9 (δ,
1JCF = 237 Hz), 162.0.
N-(4-Chlorophenyl)benzo[d]thiazol-2-amine8 (3d)
White solid, mp 208–209◦C; 1H NMR (400 MHz, DMSO-d6): δ = 7.19 (t, J = 8.4
Hz, 1H), 7.36 (d, J = 8.0 Hz, 1H), 7.43 (d, J = 8.8 Hz, 2H), 7.63 (d, J = 8.0 Hz, 1H),
7.83 (d, J = 8.4 Hz, 2H); 13C NMR (100 MHz, DMSO-d6): δ = 119.1, 119.3, 121.0, 122.4,
125.4, 125.9, 128.8, 129.9, 139.5, 151.9, 162.2.
N-(4-Methoxyphenyl)benzo[d]thiazol-2-amine8 (3e)
White solid, mp 153–155◦C; 1H NMR (400 MHz, CDCl3): δ = 3.84 (s, 3H), 6.96 (d,
J = 8.8 Hz, 2H), 7.09 (t, J = 7.6 Hz, 1H), 7.27 (t, J = 7.2 Hz, 1H), 7.38-7.48 (m, 3H), 7.57
(d, J = 8.0 Hz, 1H), 9.77 (br, 1H); 13C NMR (100 MHz, CDCl3): δ = 55.5, 114.8, 118.8,
120.8, 121.9, 124.2, 126.0, 129.7, 133.0, 151.6, 157.4, 167.3.
N-p-Tolylbenzo[d]thiazol-2-amine8 (3f)
White solid, mp 178–179◦C; 1H NMR (400 MHz, CDCl3): δ = 2.37 (s, 3H), 7.13 (d,
J = 8.4 Hz, 1H), 7.21 (d, J = 8.0 Hz, 2H), 7.31 (t, J = 8.0 Hz, 1H), 7.37 (d, J = 8.4 Hz,
2H), 7.53 (d, J = 8.0 Hz, 1H), 7.60 (d, J = 8.0 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ
= 20.9, 119.1, 120.8, 121.2, 122.1, 126.0, 129.8, 130.1, 134.6, 137.4, 151.5, 165.9.

SYNTHESIS OF 2-AMINOBENZOAZOLES
1787
N-Ethylbenzo[d]thiazol-2-amine8 (3g)
White solid, mp 114–116◦C; 1H NMR (400 MHz, CDCl3): δ = 1.32 (t, J = 7.2 Hz,
3H), 3.45 (q, J = 7.2 Hz, 2H), 6.23 (br, 1H), 7.05 (t, J = 7.6 Hz, 1H), 7.26 (t, J = 7.6 Hz,
1H), 7.52 (d, J = 8.0 Hz, 1H), 7.58 (d, J = 7.6 Hz, 1H); 13C NMR (100 MHz, CDCl3):
δ = 14.9, 40.4, 118.7, 120.8, 121.4, 126.0, 130.2, 152.3, 167.7.
N-Cyclohexylbenzo[d]thiazol-2-amine7 (3h)
1H NMR (400 MHz, CDCl3): δ = 1.18–1.45 (m, 5H), 1.61–1.77 (m, 3H), 2.11–2.13
(m, 3H), 3.5 (br, 1H), 5.79 (br, 1H), 7.05 (t, J = 7.2 Hz, 1H), 7.27 (t, J = 7.2 Hz, 1H), 7.52
(d, J = 8.0 Hz, 1H), 7.57 (d, J = 8.0 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ = 24.8,
25.4, 33.2, 54.6, 118.6, 120.7, 121.2, 125.8, 130.3, 152.4, 166.9.
6-Methoxy-N-phenylbenzo[d]thiazol-2-amine (3i)
1H NMR (400 MHz, CDCl3): δ = 3.80 (s, 3H), 6.91 (dd, J = 2.4, 8.8 Hz, 1H), 7.11
(t, J = 7.2 Hz, 1H), 7.14 (d, J = 2.4 Hz, 1H), 7.35 (t, J = 8.0 Hz, 2H), 7.44 (s, 1H), 7.47
(t, J = 8.8 Hz, 2H), 8.40 (br, 1H); 13C NMR (100 MHz, CDCl3): δ = 55.9, 105.3, 114.0,
119.9, 120.0, 123.9, 129.4, 131.1, 140.2, 145.8, 155.9, 162.6.
6-Methoxy-N-p-tolylbenzo[d]thiazol-2-amine (3j)
1H NMR (400 MHz, CDCl3): δ = 2.34 (s, 3H), 3.80 (s, 3H), 6.90 (dd, J =
2.4, 8.8 Hz, 1H), 7.12 (d, J = 2.8 Hz, 1H), 7.17 (d, J = 8.4 Hz, 2H), 7.33 (d,
J = 8.4 Hz, 2H), 7.44 (d, J = 8.8 Hz, 2H), 8.35 (br, 1H); 13C NMR (100 MHz, CDCl3): δ
= 20.2, 55.4, 104.8, 113.3, 119.2, 120.1, 129.5, 130.6, 133.5, 137.1, 145.4, 155.2, 162.9.
N-(4-Chlorophenyl)-6-methoxybenzo[d]thiazol-2-amine (3k)
1H NMR (400 MHz, CDCl3): δ = 3.83 (s, 3H), 6.95 (dd, J = 2.4, 8.8 Hz, 1H), 7.16
(d, J = 1.6 Hz, 1H), 7.32 (d, J = 8.4 Hz, 2H), 7.45 (d, J = 8.8 Hz, 2H), 7.54 (d, J = 8.4
Hz, 1H); 13C NMR (100 MHz, CDCl3): δ = 56.0, 105.3, 114.2, 120.5, 120.6, 128.7, 129.5,
131.4, 138.7, 146.0, 156.3, 161.9.
6-Bromo-N-phenylbenzo[d]thiazol-2-amine (3l)
1H NMR (400 MHz, CDCl3): δ = 7.20 (t, J = 6.8 Hz, 1H), 7.38-7.44 (m, 4H), 7.48
(d, J = 8.4 Hz, 2H), 7.73 (s, 1H), 7.54 (d, J = 8.4 Hz, 1H); 13C NMR (100 MHz, CDCl3):
δ = 114.9, 120.2, 120.6, 123.3, 124.7, 129.4, 129.6, 131.7, 139.3, 150.5, 164.0.
6-Bromo-N-p-tolylbenzo[d]thiazol-2-amine (3m)
1H NMR (400 MHz, CDCl3): δ = 2.36 (s, 3H), 7.20 (d, J = 8.0 Hz, 2H), 7.33 (d, J
= 8.4 Hz, 2H), 7.40 (s, 2H), 7.70 (s, 1H); 13C NMR (100 MHz, CDCl3): δ = 20.9, 114.6,
120.3, 121.0, 123.3, 129.3, 130.2, 131.7, 134.9, 136.8, 150.6, 165.5.

1788
Q. DING ET AL.
6-Bromo-N-(4-chlorophenyl)benzo[d]thiazol-2-amine (3n)
1H NMR (400 MHz, CDCl3): δ = 7.36 (d, J = 8.8 Hz, 2H), 7.46–7.49 (m, 4H), 7.75
(s, 1H); 13C NMR (100 MHz, CDCl3): δ = 115.3, 120.8, 121.1, 123.4, 124.0, 129.5, 129.6,
131.7, 137.9, 150.4, 163.5.
6-Iodo-N-phenylbenzo[d]thiazol-2-amine (3o)
1H NMR (400 MHz, CDCl3): δ = 7.17 (t, J = 7.6 Hz, 1H), 7.31 (d, J = 8.4 Hz, 1H),
7.39 (t, J = 7.6 Hz, 2H), 7.60 (d, J = 8.4 Hz, 2H), 7.59 (dd, J = 1.6, 8.4 Hz, 1H), 7.89 (s,
1H), 8.50 (br, 1H); 13C NMR (100 MHz, CDCl3): δ = 120.3, 121.1, 124.7, 129.1, 129.5,
129.6, 135.1, 139.4, 151.8.
6-Iodo-N-p-tolylbenzo[d]thiazol-2-amine (3p)
1H NMR (400 MHz, CDCl3): δ = 2.36 (s, 3H), 7.22 (t, J = 7.6 Hz, 2H), 7.25 (s, 1H),
7.33 (d, J = 7.6 Hz, 2H), 7.56 (d, J = 8.4 Hz, 2H), 7.87 (s, 1H), 8.75 (br, 1H); 13C NMR
(100 MHz, CDCl3): δ = 20.9, 84.3, 120.7, 121.3, 129.0, 130.2, 132.1, 135.0, 136.9, 151.1,
165.8.
N-(4-Chlorophenyl)-6-iodobenzo[d]thiazol-2-amine (3q)
1H NMR (400 MHz, DMSO-d6): δ = 7.35–7.38 (m, 3H), 7.59 (d, J = 7.6 Hz, 2H),
7.76 (d, J = 7.6 Hz, 1H), 8.15 (s, 1H), 10.67 (br, 1H); 13C NMR (100 MHz, DMSO-d6):
δ = 85.2, 119.3, 121.2, 125.7, 128.8, 129.0, 132.5, 134.5, 139.0, 151.4, 161.6.
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