Synthesis of dithiocarbamates by Markovnikov addition reaction in PEG and their application in amidoalkylation of naphthols and indoles

Article abstract of DOI:10.5935/0103-5053.20150119

Synthesis of dithiocarbamates by the one-pot three-component Markovnikov addition reaction of an amine, carbon disulfide and an alkyl vinyl ether or N-vinylpyrrolidone is reported in polyethylene glycol (PEG) under a mild and green procedure with high yields and completely regiospecific. Also, the products were used as efficient starting materials for amidoalkylation of electron-rich arenes such as naphthols and indoles.

Full text of DOI:10.5935/0103-5053.20150119

http://dx.doi.org/10.5935/0103-5053.20150119
J. Braz. Chem. Soc., Vol. 26, No. 7, 1500-1508, 2015.
Printed in Brazil - ©2015 Sociedade Brasileira de Química
0103 - 5053 $6.00+0.00
Article
A
Synthesis of Dithiocarbamates by Markovnikov Addition Reaction in PEG and
Their Application in Amidoalkylation of Naphthols and Indoles
Azim Ziyaei Halimehjani,*,a Arefeh Dadras,b Meraj Ramezani,b Elham V. Shamiri,a
Seyyed E. Hooshmanda and Mohammad M. Hashemib
aFaculty of Chemistry, Kharazmi University, 49 Mofateh St., Tehran, Iran
bDepartment of Chemistry, Sharif University of Technology, P.O. Box 11465-9516, Tehran, Iran
Synthesis of dithiocarbamates by the one-pot three-component Markovnikov addition
reaction of an amine, carbon disulfide and an alkyl vinyl ether or N-vinylpyrrolidone is reported
in polyethylene glycol (PEG) under a mild and green procedure with high yields and completely
regiospecific. Also, the products were used as efficient starting materials for amidoalkylation of
electron-rich arenes such as naphthols and indoles.
Keywords: dithiocarbamate, Markovnikov addition, alkyl vinyl ether, N-vinylpyrrolidone,
polyethylene glycol
Introduction
isothiocyanate which suffer from many drawbacks such
as long reaction time, harsh reaction conditions and use
of an expensive and toxic reagent, base and solvent. Due
to the wide applications of dithiocarbamates, several
useful procedures for the synthesis of these compounds
have been developed by our group and others, via the
one-pot condensation of amines, carbon disulfide and
electrophiles such as alkyl halides, epoxides, carbonyl
compounds and α,β-unsaturated compounds.19-23 Very
recently, a deep eutectic solvent (DES) was used by Azizi
and Gholibeglo24 for synthesis of dithiocarbamates in high
yields via a one-pot, three-component Michael addition of
an amine and carbon disulfide to an activated olefin. Due
to the aforementioned applications of dithiocarbamates,
synthesis of these compounds with different substitution
patterns by a convenient and safe method has become a
field of increasing interest in recent years.
Solvents play a critical role in organic reactions for
mixing the ingredients to allow molecular interactions.
Performing organic reactions without using harmful organic
solvents is now of great interest in green organic synthesis.
For this purpose, attempts have been made toward the use
of green mediums such as water, supercritical fluids, ionic
liquids and fluorous based systems. Polyethylene glycol
(PEG) has recently been considered as a novel, recyclable
and eco-friendly solvent in synthetic chemistry for various
organic transformations25-29 with odd properties such as
commercial availability, thermal stability, low volatility,
Dithiocarbamates are the analogue of carbamates in
which both oxygen atoms are replaced by sulfur atoms.
The dithiocarbamate group is a valuable pharmacophore
that induces various biological activity when incorporated
into a particular structure.1-4 Their biological potencies
such as anti-histaminic, anti-bacterial, and anti-cancer
are noteworthy.5-7 They constitute a large family of
herbicides, fungicides and pesticides in agriculture and
several compounds of this category such as zineb, maneb,
nabam, ziram and ferbam have been commercialized.
Also, their applications as sulfur vulcanization agents in
rubber manufacturing,8 and radical chain transfer agents
in the reversible addition-fragmentation chain-transfer
(RAFT) polymerizations are extensively investigated.9
Furthermore, they have been used as versatile synthons
for the preparation of diversities of organic materials
such as thioureas,10 isothiocyanates,11 2-imino-1,3-
dithiolanes,12 cyanamides,13 heterocyclic rings,14 the
protection of aldehydes,15 amide bond formation,16 and
protection of the amino groups in peptide synthesis.17
Also, dithiocarbamates are important ligands in metal
complexes.18
The classical synthesis of dithiocarbamates involves
the use of thiophosgene, a chlorothioformate and an
*e-mail: ziyaei@khu.ac.ir

Vol. 26, No. 7, 2015
Ziyaei Halimehjani et al.
1501
and biodegradability and immiscibility with a number
of organic solvents. Generally, PEG is an inexpensive,
non-toxic, bio-compatible and completely non-halogenated
solvent. The fast growth of published works about PEGs in
medicinal areas reflects the importance of PEG polymers
mainly related to their low toxicity.30,31 This inspired us
to concentrate on synthesis of the biologically active
dithiocarbamates under catalyst-free conditions using PEG
as green medium.
We then evaluated the scope and limitations of the
protocol by employing a wide range of amines and electron-
rich alkenes. The results are summarized in Tables 1 and 2.
Various cyclic and acyclic alkyl vinyl ethers such as ethyl
vinyl ether, ethyl propenyl ether and 2,3-dihydropyrane
were examined with high to excellent yields (Table 1).
N-Vinylpyrrolidone was also used in this transformation
to afford excellent yields of products (Table 2). Primary
aliphatic amines such as benzyl amine, allyl amine,
cyclohexyl amine, furfuryl amine and butyl amine all
gave excellent yields (entries 1-4, Table 1; and entries 1-4,
Table 2). In addition, secondary amines such as pyrrolidine,
piperidine, morpholine, azepane, diethyl amine, and diallyl
amine reacted equally well in this protocol (entries 5-12,
Table 1; entries 5-9, Table 2). Aromatic amines were not
suitable starting materials for this transformation due to
their low nucleophilic property toward carbon disulfide.
The present method is experimentally simple and generates
no byproducts. In addition, the reaction is regiospecific
toward Markovnikov adducts. The PEG-200 can be simply
recovered and reused in the reactions without a significant
yield loss.
Having successfully synthesized Markovnikov
adducts, we focused our attention on using the product 4
as suitable starting material for amidoalkylation of
electron-rich arenes in the presence of AlCl3 in refluxing
chloroform (Scheme 2). The results are summarized in
Table 3. Electron-rich arenes such as indoles and naphthols
were used in this Mannich-type amidoalkylation reaction
and moderate to good yields of products were obtained.
N,N-Dialkylanilines, dimethoxybenzene, catechol,
2-methoxy naphthalene, pyrrole and thiophene were
also examined for this reaction without any result. The
Markovnikov products of alkyl vinyl ethers were not
suitable starting materials for this transformation.
Results and Discussion
Previous reports by our group revealed that although
high to excellent yields were obtained in the reaction of
dithiocarbamates with alkyl vinyl ethers 1 in water,22 for
N-vinylpyrrolidine 2, the reaction gave excellent yields
under solvent-free conditions and no valuable yields
were obtained in water.23 To overcome this drawback,
we focused our investigation to find an efficient reaction
medium to be suitable for both systems. In continuation
of our research allocated to the progress of green
chemistry32-36 and the chemistry of dithiocarbamates,
herein we report a new and efficient protocol for synthesis
of dithiocarbamates by Markovnikov addition reaction
in PEG as a green and environmentally benign solvent at
room temperature without using any catalyst as outlined
in Scheme 1.
Initially, we examined the one-pot three-component
reaction of pyrrolidine (5 mmol), CS2 (6 mmol), and
ethyl vinyl ether (6 mmol) in liquid polyethylene glycols
such as PEG-200 and PEG-400. We found that excellent
yield was obtained in PEG-200 (94%) in comparison to
PEG-400 (65%). Also, mixing the starting materials at
room temperature for 24 h was the best condition observed
for this reaction.
S
R
N
R
S
O
O
3
R
R
1
PEG-200
r.t.
NH
CS2
or
N
or
+
+
O
S
N
O
2
R
S
N
R
4
Scheme 1. A one-pot three-component synthesis of Markovnikov adducts.

1502
Synthesis of Dithiocarbamates by Markovnikov Addition Reaction in PEG
J. Braz. Chem. Soc.
Table 1. Markovnikov addition reaction of dithiocarbamates to vinyl ethers
S
PEG-200
r.t.
RR'NH + CS
+
2
NRR'
S
O
O
3
entry
1
Amine
Product
Yielda / %
S
84
93
NH2
N
H
S
O
3a
S
NH2
2
3
3b
N
S
O
H
S
NH2
66
95
N
H
S
O
3c
S
O
NH2
4
5
N
H
S
O
3d
O
S
N
S
O
N
H
80
3e
S
6
7
8
88
61
64
N
S
O
NH
3f
S
O
NH
NH
NH
NH
N
S
O
3g
O
S
3h
N
S
O
S
9
3i
85
94
N
S
O
S
10
3j
N
S
O

Vol. 26, No. 7, 2015
Ziyaei Halimehjani et al.
1503
Table 1. Markovnikov addition reaction of dithiocarbamates to vinyl ethers (cont.)
entry
11
Amine
Product
Yielda / %
72
S
3k
NH
N
S
O
S
12
86
NH
3l
N
S
O
aIsolated yield.
Table 2. Markovnikov addition reaction of dithiocarbamates to N-vinylpyrrolidone
O
S
N
R
R
PEG-200
r.t.
N
NH
CS2
+
+
R
S
N
O
4
R
entry
1
Amine
Product
Yielda / %
O
4a
S
N
93
NH2
N
H
S
O
S
N
2
3
80
66
NH2
4b
N
H
S
O
S
N
NH2
4c
N
H
S
O
S
N
O
NH2
4
5
95
61
4d
N
H
S
O
O
S
N
O
NH
4e
N
S
O

1504
Synthesis of Dithiocarbamates by Markovnikov Addition Reaction in PEG
J. Braz. Chem. Soc.
Table 2. Markovnikov addition reaction of dithiocarbamates to N-vinylpyrrolidone (cont.)
entry
Amine
Product
Yielda / %
O
S
N
6
94
88
NH
4f
N
S
O
4g
S
N
7
8
NH
N
S
O
S
N
64
85
NH
4h
N
S
O
S
N
9
NH
4i
N
S
aIsolated yield.
O
N
OH
OH
5
O
N
AlCl3
N
S
or
or
+
CHCl3
, reflux
S
N
O
N
H
N
H
4f
6
Scheme 2. Mannich-type amidoalkylation of electron-rich arenes.
Conclusions
Regiospecificity for the Markovnikov adducts, clean
reaction conditions, catalyst-free, and simple experimental
procedures are the main advantages of this reaction. Also,
the products were applied for the Friedel-Craft (Mannich)
type amidoalkylation of electron-rich arenes such as indoles
and naphthols.
In summary, the PEG-200 has been employed as
a novel, mild and highly efficient solvent for the one-
pot three-component synthesis of dithiocarbamates via
Markovnikov addition reaction in high to excellent yields.

Vol. 26, No. 7, 2015
Ziyaei Halimehjani et al.
1505
Table 3. Mannich-type amidoalkylation of naphthols and indoles with dithiocarbamates prepared from Markovnikov reaction
entry
Arene
Dithiocarbamate
Product
Yielda / %
O
OH
O
N
S
N
1
81
OH
N
S
5a
OH
OH
O
O
S
N
N
OH
2
62b
O
N
S
+
N
5b
5b'
O
O
HO
OH
N
S
N
3
4
5
70
70
85
HO
OH
N
S
5c
N
O
S
N
6a
O
N
N
S
H
N
H
O
O
S
N
N
CH3
N
H
6b
N
S
CH3
N
H
N
Br
O
S
N
Br
6
73
O
6c
N
H
N
S
N
H
N
O
S
N
7
82
O
N
N
S
6d
N
CH3
CH3
aIsolated yield; btotal yields of regioisomers (5b:5b’ = 2:1).

1506
Synthesis of Dithiocarbamates by Markovnikov Addition Reaction in PEG
J. Braz. Chem. Soc.
Experimental
64.0, 94.4, 191.6; anal. calcd. for C10H19NOS2: C, 51.46; H,
8.21; N, 6.00; found: C, 51.23; H, 8.07; N, 6.12.
All reactions were carried out in an atmosphere of air.
All chemicals and solvents except water (tap water) were
purchased from Merck or Fluka and used as received. All
reactions were monitored by thin layer chromatography
(TLC) on silica gel 60 F254 (0.25 mm), and visualization
was performed with UV. The 1H and 13C nuclear magnetic
resonance (NMR) spectra were recorded on a BrukerAMX
300-MHz spectrometer in CDCl3 with tetramethylsilane
(TMS) as internal standard. Melting points were determined
with a Branstead-Electrothermal 9200 apparatus and are
uncorrected. Elemental analyses were conducted with a
Perkin-Elmer 2004 (II) CHN analyzer.
General procedure for amidoalkylation of electron-rich
arenes 5a-c and 6a-d
In a 25 mL round bottom flask equipped with
magnetic stirrer bar, an electron-rich arene (1 mmol),
a dithiocarbamate 4 (1 mmol), chloroform (5 mL) and
10 mol% ofAlCl3 were added and the mixture was refluxed
for 5-8 h. Progress of the reaction was monitored by
TLC. After reaction completion, H2O (10 mL) and CHCl3
(10 mL) were added and the mixture was filtered to remove
any undissolved materials. The filtrate was transferred
to a decanter and the organic phase was separated. After
treatment with Na2SO4, the solvent was evaporated to
give the crude products. Purification was performed by
recrystallization from ethyl acetate/petroleum.
General procedure for the synthesis of Markovnikov adducts
3a-l and 4a-i
To a mixture of an amine (5 mmol) and CS2 (6 mmol)
in PEG (10 mL) was added an electrophile (alkyl vinyl
ether or N-vinyl pyrrolidine, 6 mmol). The reaction mixture
was stirred vigorously at room temperature for 24 h. After
completion of the reaction, H2O (10 mL) was added and
the product was extracted with EtOAc (2 × 20 mL) and
combined organic layers were washed with H2O and dried
over anhydrous Na2SO4. The solvent was evaporated under
reduced pressure to give the corresponding product with
high purity without the need of column chromatography
for purification. The PEG-200 can be recovered from the
aqueous phase by passing the aqueous solution through
activated charcoal and evaporation of water.All compounds
were characterized on the basis of their spectroscopic data
(1H and 13C NMR, CHN analysis) and by comparison with
those reported in the literature.22,23
1-(1-(2-Hydroxynaphthalen-1-yl)ethyl)pyrrolidin-2-one (5a)
Pale yellow solid; m.p. 198-200 °C; 1H NMR (300 MHz,
DMSO-d6) d 1.67 (d, 3H, J 7.2 Hz, CH3), 2.13-2.23 (m, 4H,
2CH2), 3.13 (m, 1H, CH2N), 3.56 (m, 1H, CH2N), 5.94 (q,
1H, J 7.2 Hz, CH), 7.14 (d, 1H, J 8.8 Hz, Ar–H), 7.25 (m,
1H,Ar–H), 7.40 (m, 1H,Ar–H), 7.68-7.76 (m, 2H, 2Ar–H),
8.10 (d, 1H, J 8.8 Hz, Ar–H), 9.8 (brs, 1H, OH); 13C NMR
(75 MHz, DMSO-d6) d 17.3, 17.5, 30.6, 43.5, 44.4, 116.5,
119.1, 122.4, 126.5, 127.5, 128.3, 128.4, 129.2, 133.3,
154.5, 172.9; anal. calcd. for C16H17NO2: C, 75.27; H, 6.71;
N, 5.49; found: C, 74.96; H, 6.71; N, 5.66.
1-(1-(1-Hydroxynaphthalen-2-yl)ethyl)pyrrolidin-2-one (5b)
1
Cream solid; m.p. 190-192 °C; H NMR (300 MHz,
DMSO-d6) d 1.53 (d, 3H, J 6.8 Hz, CH3), 1.58 (m, 1H, CH2),
1.60 (m, 1H, CH2), 2.16-2.39 (m, 2H, CH2), 2.44 (m, 1H,
CH2N), 3.20 (m, 1H, CH2N), 5.79 (q, 1H, J 6.8 Hz, CH),
6.85 (d, 1H, J 8.1 Hz, Ar–H), 7.37-7.50 (m, 3H, 3Ar–H),
7.89 (d, 1H, J 8.1 Hz, Ar–H), 8.15 (m, 1H, Ar–H), 10.18
(brs, 1H, OH); 13C NMR (75 MHz, DMSO-d6) d 16.3,
17.2, 30.8, 41.6, 44.5, 106.9, 122.6, 122.8, 124.4, 124.8
(2C), 125.5, 126.6, 132.3, 153.0, 172.6; anal. calcd. for
C16H17NO2: C, 75.27; H, 6.71; N, 5.49; found: C, 75.66;
H, 6.76; N, 5.47.
1-Ethoxyethyl azepane-1-carbodithioate (3i)
Viscous oil; 1H NMR (300 MHz, CDCl3) d 1.03 (t, 3H,
J 7.0 Hz, CH3), 1.42 (brs, 4H, 2CH2), 1.54 (d, 3H, J 6.3 Hz,
CH3), 1.69 (brs, 4H, 2CH2), 3.45 (m, 1H, CH2O), 3.59 (m,
1H, CH2O), 3.75 (t, 2H, J 6.0 Hz, CH2N), 4.01 (m, 2H,
CH2N), 5.77 (q, 1H, J 6.2 Hz, CH); 13C NMR (75 MHz,
CDCl3) d 14.5, 22.9, 25.4, 25.9, 26.0, 27.2, 52.4, 54.4, 63.9,
90.1, 194.7; anal. calcd. for C11H21NOS2: C, 53.40; H, 8.55;
N, 5.66; found: C, 53.75; H, 8.71; N, 5.52.
1-(1-(2,7-Dihydroxynaphthalen-8-yl)ethyl)pyrrolidin-2-one
1-Ethoxypropyl pyrrolidine-1-carbodithioate (3l)
(5c)
Viscous oil; 1H NMR (300 MHz, CDCl3) d 0.89 (t, 3H,
J 7.3 Hz, CH3), 1.03 (t, 3H, J 7.0 Hz, CH3), 1.79-1.94 (m,
6H, 3CH2), 3.45-3.59 (m, 4H, CH2N and CH2O), 3.74 (t,
2H, J 6.9 Hz, CH2N), 5.70 (t, 1H, J 6.1 Hz, CH); 13C NMR
(75 MHz, CDCl3) d 9.7, 14.4, 23.7, 26.1, 29.8, 50.2, 54.0,
Cream solid; m.p. 206-208 °C; H NMR (300 MHz,
1
DMSO-d6) d 1.53 (d, 3H, J 7.1 Hz, CH3), 1.63-2.23 (m,
4H, 2CH2), 3.15 (m, 1H, CH2N), 3.55 (m, 1H, CH2N), 5.73
(q, 1H, J 7.1 Hz, CH), 6.82 (dd, 1H, J 8.8, 1.8 Hz, Ar–H),
6.89 (d, 1H, J 8.8 Hz, Ar–H), 7.28 (s, 1H, Ar–H), 7.51 (d,

Vol. 26, No. 7, 2015
Ziyaei Halimehjani et al.
1507
1H, J 8.9 Hz, Ar–H), 7.55 (d, 1H, J 8.7 Hz, Ar–H), 9.58 (s,
1H, OH), 9.70 (s, 1H, OH); 13C NMR (75 MHz, DMSO-d6)
d 17.4, 21.6, 30.7, 39.5, 44.6, 104.7, 114.7, 114.9, 115.6,
122.9, 128.9, 129.9, 135.1, 154.9, 156.0, 173.0; anal. calcd.
for C16H17NO3: C, 70.83; H, 6.32; N, 5.16; found: C, 70.76;
H, 6.25; N, 5.13.
119.7, 121.9, 126.6, 126.9, 137.1, 174.0; anal. calcd. for
C15H18N2O: C, 74.35; H, 7.49; N, 11.56; found: C, 74.47;
H, 7.65; N, 11.25.
Supplementary Information
Supplementary data (copies of 1H and 13C NMR spectra
for unknown compounds) are available free of charge at
http://jbcs.sbq.org.br as PDF file.
1-(1-(1H-Indol-3-yl)ethyl)pyrrolidin-2-one (6a)
1
White solid; m.p. 164-167 °C; H NMR (300 MHz,
CDCl3) d 1.60 (d, 3H, J 7.0 Hz, CH3), 1.73-1.83 (m, 2H,
CH2), 2.41-2.88 (m, 2H, CH2), 2.86 (m, 1H, CH2N), 3.26
(m, 1H, CH2N), 5.77 (q, 1H, J 7.0 Hz, CH), 7.08-7.22 (m,
3H, 2Ar–H and 1H, pyrrole), 7.36 (d, 1H, J 8.0 Hz, Ar–H),
7.62 (d, 1H, J 8.0 Hz,Ar–H), 8.31 (brs, 1H, NH); 13C NMR
(75 MHz, CDCl3) d 16.6, 17.7, 31.3, 42.2, 42.5, 111.0,
116.2, 119.5, 119.6, 121.1, 122.0, 126.4, 136.4, 174.2; anal.
calcd. for C14H16N2O: C, 73.66; H, 7.06; N, 12.27; found:
C, 74.01; H, 7.21; N, 12.61.
Acknowledgements
We are grateful to the Research Council of Sharif
University of Technology for financial support. We also
thank the Faculty of Chemistry of Kharazmi University
for supporting this work.
References
1-(1-(2-Methyl-1H-indol-3-yl)ethyl)pyrrolidin-2-one (6b)
1. Kumar, S. T. V. S.; Kumar, L.; Sharma, V. L.; Jain, A.; Jain,
R. K.; Maikhuri, J. P.; Kumar, M.; Shukla, P. K.; Gupta, G.;
Eur. J. Med. Chem. 2008, 43, 2247.
1
White solid; m.p. 176-179 °C; H NMR (300 MHz,
CDCl3): d 1.74 (d, 3H, J 7.3 Hz, CH3), 1.75-1.96 (m, 2H,
CH2), 2.34-2.43 (m, 2H, CH2), 2.51 (s, 3H, CH3), 3.17 (m,
1H, CH2N), 3.57 (m, 1H, CH2N), 5.76 (q, 1H, J 7.3 Hz,
CH), 7.07-7.16 (m, 2H, 2Ar–H), 7.29 (dd, 1H, J 7.8, 2.0 Hz,
Ar–H), 7.72 (d, 1H, J 7.8 Hz, Ar–H), 8.06 (brs, 1H, NH);
13C NMR (75 MHz, CDCl3) d 12.6, 17.5, 17.7, 31.4, 43.4
(2C), 110.4, 110.6, 119.3, 119.5, 121.1, 127.9, 133.2, 135.0,
173.7; anal. calcd. for C15H18N2O: C, 74.35; H, 7.49; N,
11.56; found: C, 73.93; H, 7.65; N, 11.26.
2. Kumar, L.; Lal, N.; Kumar, V.; Sarswat, A.; Jangir, S.; Bala, V.;
Kumar, L.; Kushwaha, B.; Pandey,A. K.; Siddiqi, M. I.; Shukla,
P. K.; Maikhuri, J. P.; Gupta, G.; Sharma, V. L.; Eur. J. Med.
Chem. 2013, 70, 68 and references therein.
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Pharm. 1996, 46, 169.
4. Ates, O.; Kocabalkanli, A.; Cesur, N.; Otuk, G.; Il Farmaco
1998, 53, 541.
5. Thorn, G. D.; Ludwig, R.A.; The Dithiocarbamates and Related
Compounds; Elsevier: Amsterdam, 1962.
1-(1-(5-Bromo-1H-indol-3-yl)ethyl)pyrrolidin-2-one (6c)
1
White solid; m.p. 155-157 °C; H NMR (300 MHz,
6. Aboul-Fadl, T.; El-Shorbagi, A.; Eur. J. Med. Chem. 1996, 31,
165.
CDCl3) d 1.58 (d, 3H, J 7.0 Hz, CH3), 1.83-1.94 (m,
2H, CH2), 2.44-2.49 (m, 2H, CH2), 2.86 (m, 1H, CH2N),
3.27 (m, 1H, CH2N), 5.70 (q, 1H, J 7.0 Hz, CH), 7.15
(s, 1H, pyrrole ring), 7.24-7.31 (m, 2H, 2Ar–H), 7.74
(s, 1H, Ar‑H), 8.70 (brs, 1H, NH); 13C NMR (75 MHz,
CDCl3) d 16.6, 17.7, 31.6, 42.2, 42.4, 112.7, 113.1, 115.7,
121.8, 123.3, 125.3, 128.0, 135.1, 174.3; anal. calcd. for
C14H15BrN2O: C, 54.74; H, 4.92; N, 9.12; found: C, 54.53;
H, 4.83; N, 9.43.
7. Gerhauser, C.;You, M.; Liu, J.; Moriarty, R. T.; Hawthorne, M.;
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Submitted: March 6, 2015
Published online: May 12, 2015