Bisdiazonium tetrafluoroborates as arylating agents in anionarylation of acrylamides and methacrylamides

Article abstract of DOI:10.1134/S1070363213110121

Bisdiazonium tetrafluoroborates derived from benzidine, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenylsulfone have been used as arylating reagents in the reactions of chloro-, bromo-, and thiocyanatoarylation of acrylamides and methacrylamides. Ani

Full text of DOI:10.1134/S1070363213110121

ISSN 1070-3632, Russian Journal of General Chemistry, 2013, Vol. 83, No. 11, pp. 2040–2043. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © V.S. Baranovskii, V.N. Yatsyuk, B.D. Grishchuk, 2013, published in Zhurnal Obshchei Khimii, 2013, Vol. 83, No. 11, pp. 1843–
1846.
Bisdiazonium Tetrafluoroborates as Arylating Agents
in Anionarylation of Acrylamides and Methacrylamides
V. S. Baranovskii, V. N. Yatsyuk, and B. D. Grishchuk
Hnatiuk Ternopil National Pedagogical University, ul. M. Krivonosa 2, Ternopil, 46027 Ukraine
e-mail: baranovsky@tnpu.edu.ua
Received December 25, 2012
Abstract—Bisdiazonium tetrafluoroborates derived from benzidine, 4,4'-diaminodiphenylmethane, and 4,4'-
diaminodiphenylsulfone have been used as arylating reagents in the reactions of chloro-, bromo-, and
thiocyanatoarylation of acrylamides and methacrylamides. Anionarylation proceeds via two diazo groups to
give 3,3'-[4,4'-biphenyl(methane, sulfone)]bis[2-chloro(bromo, thiocyanato)(2-methyl)propionamides].
DOI: 10.1134/S1070363213110121
Aryldiazonium salts prepared from aniline and its
derivatives, complexes of diazonium salts with copper
[1, 2], and triazenes [3] are efficient arylating gents in
the Meerwein reactions [4] and anionarylation [5].
bisdiazonium tetrafluoroborates based on benzidine
and its derivatives as arylating reagents. To the very
best of our knowledge, the only related reference is
[10], describing O,O-dialkyldithiophosphatoarylation
of methyl acrylate and methyl methacrylate with 4,4'-
biphenyl(oxide)bisdiazonium tetrafluoroborate to form
bisadducts with low yields (about 15%).
Development of new arylating agents for anion-
arylation of unsaturated compounds is an important
field of modern organic synthesis. Bisdiazonium salts
of benzidine and its derivatives are especially promis-
ing; however, to date their behavior has been studied in
detail only under conditions of chloroarylation and the
Meerwein reactions [4, 6]. For example, bisdiazonium
chlorides derived from benzidine and diaminodi-
phenylmethane(oxide) react with acrylates, metha-
crylates, and acrylonitrile to form the products of
chloroarylation via both diazo groups [7]. In the case
of 4,4'-biphenyl(methane, oxide)bisdiazonium tetrafluoro-
borate in the presence of chloride anions, the reaction
regioselectivity does not change except for chloro-
arylation of styrene and its derivatives. In the latter
reactions, formation of the products of arylation via
one diazo group and a parallel substitution of the
second group with the chlorine atom (the Sandmeyer
reaction) have been observed as well [8].
In particular, in this work we present the first report
on application of bisdiazonium salts derived from
benzidine, 4,4'-diaminodiphenylmethane, and 4,4'-di-
aminodiphenylsulfone in the reactions of chloro-, bromo-
and thiocynatoarylation. Acrylamides and metha-
crylamides, reactive substrates of anionarylation reac-
tions [11, 12], were selected as model compounds.
4,4'-Diphenyl(methane, sulfone)bisdiazonium tetra-
fluoroborates reacted with acrylamide and methacryl-
amide in the presence of chloride, bromide, or thio-
cyanate anions to give 3,3'-[4,4'-diphenyl(methane,
sulfone)]bis[2-chloro(bromo, thiocyanato)(2-methyl)pro-
pionamides] I–XVIII, the bisanionarylation products.
Chloro- and bromoarylation of acrylamides and
methacrylamides proceeded in water–acetone (1 : 2)
medium in the presence of sodium chloride or potas-
sium bromide, respectively, and catalytic amount of
copper(II) chloride (bromide) at 15–30°C. Thiocyanato-
arylation occurred in water–acetone (1 : 3) medium at
–25 to –10°C in the presence of potassium thiocyanate
and copper(II) tetrafluoroborate as catalyst. The
optimal ratio of bisdiazonium salt/amide/anionoid
reagent/catalyst was of 1 : 2.1 : 2.1 : 0.1. The yields of
Substituting at the diazonium salt aromatic core does
not influence the regioselectivity of chloro-arylation of
acrylates, methacrylates and acrylonitrile: with 3,3'-
dichloro-4,4'-diphenylmethanebisdiazonium chloride their
reactions lead to the bischloroarylated adducts [9].
In order to further extend the synthetic capabilities
of anionarylation, we investigated the application of
2040

BISDIAZONIUM TETRAFLUOROBORATES AS ARYLATING AGENTS
O
2041
BF4_ N
+
N
NBF4_
+
2
+ 2MAn
NH2
+
N
X
R
R
R
O
O
2MBF4
+ 2N2 +
X
NH2
An
H N
An
2
I_XVIII
An = Cl (I–VI), Br (VII–XII), SCN (XIII–XVIII); X = (I, II, VII, VIII, XIII, XIV), CH2 (III, IV, IX, X, XV, XVI), SO2
(V, VI, XI, XII, XVII, XVIII); R = H, CH3; M = Na, K.
I–XVIII were of 38–63% depending on the nucleo-
philicity of the anionoid reagent (Cl < Br < SCN). The
presence of sulfonic or methylene group in the
molecule of bisdiazonium salt did not alter the product
yield and regioselectivity of anionarylation of acryl-
amides and methacrylamides. The reaction was accom-
panied by side formation of 4,4'-dichloro(bromo, thio-
cyanato)diphenyl(methane, sulfone) with 15–30% yield
with respect to the diazonium salt. It should be noted
that even two-fold decrease in the amide amount did not
lead to formation of the monoanionarylated products.
1
Yields, melting points, elemental analysis and H
NMR spectral data on 3,3'-[4,4'-diphenyl(methane, sul-
fone)]bis[2-chloro(bromo, thiocyanato)(2-methyl)propion-
amides] I–XVIII are listed in Tables 1 and 2.
Table 1. Yields, melting points and elemental analysis data for 3,3'-[4,4'-diphenyl(methane, sulfone)]bis[2-chloro(bromo, thiocyanato)-
(2-methyl)propionamides] (І–XVIII)
Found, %
Calculated, %
Cl(Br)
Comp.
no.
Yield,
%
mp,
An
Cl
X
R
Formula
°Са
N
Cl(Br)
19.49
17.97
18.75
17.50
16.47
15.56
35.26
33.22
34.22
32.14
30.77
29.36
–
S
–
N
S
–
–
H
46
51
42
39
38
43
55
58
47
52
43
41
58
61
55
49
63
58
190
197
206
223
208
211
195
201
205
214
212
219
138
155
141
164
179
196
7.58
7.21
7.32
6.94
6.59
6.19
6.10
5.89
6.04
5.59
5.49
5.06
13.73
12.69
13.31
12.43
11.88
11.07
C18H18Cl2N2O2
C20H22Cl2N2O2
C19H20Cl2N2O2
C21H24Cl2N2O2
C18H18Cl2N2O4S
C20H22Cl2N2O4S
C18H18Br2N2O2
C20H22Br2N2O2
C19H20Br2N2O2
C21H24Br2N2O2
C18H18Br2N2O4S
C20H22Br2N2O4S
C20H18N4O2S2
C22H22N4O2S2
C21H20N4O2S2
C23H24N4O2S2
C20H18N4O4S3
C22H22N4O4S3
7.67
7.12
19.41
18.03
18.69
17.41
16.52
15.50
35.19
33.14
34.13
32.20
30.84
29.25
–
I
Cl
–
CH3
H
–
–
II
Cl
CH2
CH2
SO2
SO2
–
–
7.39
–
III
Cl
CH3
H
–
6.88
–
IV
Cl
7.52
6.94
–
6.53
7.47
7.01
–
V
Cl
CH3
H
6.12
VI
Br
6.17
VII
VIII
IX
Br
–
CH3
H
–
5.81
–
Br
CH2
CH2
SO2
SO2
–
–
5.98
–
Br
CH3
H
–
5.65
–
X
Br
6.12
5.94
15.58
14.71
15.06
14.10
20.20
19.21
5.41
6.19
5.87
15.62
14.62
15.11
14.17
20.27
19.14
XI
Br
CH3
H
5.13
XII
XIII
XIV
XV
XVI
XVII
XVIII
SCN
SCN
SCN
SCN
SCN
SCN
13.65
12.78
13.20
12.38
11.81
11.15
–
CH3
H
–
–
CH2
CH2
SO2
SO2
–
–
CH3
H
–
–
–
–
CH3
–
–
a Of the substances recrystallized from methanol.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 83 No. 11 2013

2042
BARANOVSKII et al.
1
Table 2. Н NMR data of 3,3'-[4,4'-diphenyl(methane, sulfone)]bis[2-chloro(bromo, thiocyanato)(2-methyl)propionamides]
(І–XVIII)
Comp. no.
І
Ar
7.51 d, 7.18 d
7.40 d, 7.10 d
7.14 s
–NН2
X
CH2Ar
R
7.91 s, 7.56 s
8.01 s, 7.72 s
7.65 s, 7.23 s
7.72 s, 7.35 s
7.81 s, 7.53 s
8.02 s, 7.68 s
7.81 s, 7.50 s
7.84 s, 7.61 s
7.67 s, 7.32 s
7.76 s, 7.41 s
7.85 s, 7.58 s
7.99 s, 7.70 s
7.75 s, 7.48 s
8.06 s, 7.78 s
7.77 s, 7.45 s
7.84 s, 7.53 s
7.78 s, 7.44 s
7.94 s, 7.67 s
–
3.28 d.d, 3.11 d.d
3.31 d, 3.16 d
4.60 t
1.87 s
4.54 t
1.83 s
4.62 t
1.86 s
4.52 t
1.84 s
4.46 t
1.86 s
4.49 t
1.87 s
4.23 t
1.85 s
4.21 t
1.85 s
4.27 t
1.86 s
–
ІІ
3.89 s
3.24 d.d, 3.01 d.d
3.27 d, 3.04 d
ІІІ
7.09 s
3.91 s
IV
7.84 d, 7.47 d
7.77 d, 7.36 d
7.56 d, 7.25 d
7.46 d, 7.20 d
7.18 s
–
3.33 d.d, 3.15 d.d
3.35 d, 3.14 d
V
–
VI
–
3.34 d.d, 3.18 d.d
3.35 d, 3.22 d
VII
VIII
IX
–
3.92 s
3.18 d.d, 2.94 d.d
3.21 d, 2.99 d
7.11 s
3.88 s
X
7.89 d, 7.49 d
7.81 d, 7.40 d
7.53 d, 7.23 d
7.44 d, 7.19 d
7.08 s
–
3.37 d.d, 3.19 d.d
3.31 d, 3.13 d
XI
–
XII
XIII
XIV
XV
XVI
XVII
XVIII
–
3.25 d.d, 3.07 d.d
3.43 d, 3.07 d
–
3.88 s
3.89 s
–
3.12 d.d, 2.92 d.d
3.17 d, 2.93 d
7.05 s
7.95 d, 7.53 d
7.83 d, 7.39 d
3.36 d.d, 3.16 d.d
3.34 d, 3.01 d
–
The structure of I–XVIII was confirmed by IR and
1H NMR spectral data. The IR spectra contained absorp-
tion bands of carbonyl and amide groups in the ranges
of 1660–1676 and 3386–3412 cm–1, respectively. The
spectra of bisthiocyanatoamides XIII–XVIII contained
the absorption bands of thiocyanate group at 2148–
2164 cm–1.
carbon was observed as triplet at 4.62–4.21 ppm.
Methyl protons of methacrylate moiety resonated as
singlets in the range of 1.87–1.83 ppm.
To conclude, aromatic bisdiazonium salts could be
used as efficient arylating reagents in the anionaryla-
tion reactions. The studied bisdiazonium salts revealed
similar reactivity in reactions of chloro-, bromo- and
thiocyanatoarylation. Their application allowed for
regioselective anionarylation of unsaturated com-
pounds via both diazo groups.
1
In H NMR spectra of bisanionarylated products,
the aromatic protons signals were observed at 7.95–
7.40 ppm and 7.53–7.10 ppm, assigned to the ortho-
and meta-protons of diphenyl moieties, respectively. In
the case of acrylamide derivatives, the signals of
protons of the aromatic methylene groups appeared as
two doublets of doublets at 3.37–3.12 and 3.18–
2.92 ppm; in the case of methacrylamide the respective
protons signals were observed as two doublets in the
range of 3.33–2.93 ppm. The proton signal of methine
group bonded to chlorine, bromine, or thiocyanate
EXPERIMENTAL
IR spectra (nujol) were recorded with SPECORD
1
M80 instrument. H NMR spectra (DMSO-d6 + CCl4)
were registered with Varian Mercury (400 MHz)
spectrometer relative to external standard TMS. Purity
of the prepared compounds was confirmed by TLC
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 83 No. 11 2013

BISDIAZONIUM TETRAFLUOROBORATES AS ARYLATING AGENTS
2043
[Silufol UV-254, benzene–methanol (3 : 1), benzene–
methanol–acetone (1 : 2 : 1)].
bisdiazonium tetrafluoroborate. Yield 4.7 g (58%) of
XIII and 1.1 g (21%) 4,4'-dithiocyanatobiphenyl, mp
93°C (methanol).
3,3'-(4,4'-Diphenyl)bis(2-chloropropionamide) (I).
7.5 g (0.0195 mol) of 4,4'-diphenylbisdiazonium
tetrafluoroborate was added during 2 h to a mixture of
2.8 g (0.04 mol) of acrylamide, 0.7 g (0.004 mol) of
copper(II) chloride dihydrate, and 2.3 g (0.041 mol) of
sodium chloride in 120 mL of water–acetone mixture
(1 : 3). At 30–35°C, nitrogen evolution was observed
during 120 min. After nitrogen evolution ceased, the
reaction mixture was diluted with 50 mL of water and
extracted with 100 mL of diethyl ether. The extracts
were washed with water, dried over anhydrous calcium
chloride, and stripped. The residue was kept at –20°C
to complete crystallization. The resulting solid was
recrystallized from methanol to obtain 3.3 g (46%) of I
and 1.3 g (29%) of 4,4'-dichlorobiphenyl, mp 146°C
(methanol) (mp 148°C [13]).
The corresponding bis(chloro, bromo, thiocyanato)
propionamides were prepared similarly from bisdiazo-
nium tetrafluoroborates, derived in turn from 4,4'-di-
aminodiphenylmethane and 4,4'-diaminodiphenylsulfone.
REFERENCES
1. Dombrovski, A.V., Russ. Chem. Rev., 1984, vol. 53,
no. 10, p. 943.
2. Grishhchuk, B.D., Gorbovoi, P.M., Ganushchak, N.I.,
and Dombrovskii, A.V., Russ. Chem. Rev., 1994,
vol. 63, no. 3, p. 257.
3. Obushak, M.D., Lyakhovych, M.B., and Ganushchak, M.I.,
Tetrahedron Lett., 1998, vol. 39, p. 9567.
4. Obushak, N.D., Liakhovich, M.B., Fedorovich, I.S., and
Ganushchak, N.I., Zh. Org. Khim., 1996, vol. 32, no. 10,
p. 1522.
3,3'-(4,4'-Diphenyl)bis(2-bromopropionamide)
(VII). 7.5 g (0.0195 mol) of 4,4'-diphenylbisdiazonium
tetrafluoroborate was added during 1 h to a mixture of
2.8 g (0.04 mol) of acrylamide, 1.0 g (0.004 mol) of
copper(II) bromide dehydrate, and 4.0 g (0.041 mol) of
potassium bromide in 150 mL of water–acetone
mixture (1 : 3). At 15–20°C, nitrogen evolution was
ob-served during 90 min. After nitrogen evolution
ceased, the reaction mixture was diluted with 50 mL of
water and extracted with 100 mL of diethyl ether. The
extracts were washed with water, dried over anhydrous
calcium chloride, and stripped. The solid residue was
kept at –20°C to complete crystallization. The result-
ing solid was recrystallized from methanol to obtain
4.9 g (55%) of VII and 1.6 g (26%) of 4,4'-di-
brombiphenyl, mp 168°C (methanol) (mp 166.5°C
[13]).
5. Naidan, V.M. and Smalius, V.V., Russ. J. Gen. Chem.,
2005, vol. 75, no. 11, p. 1771.
6. Grishchuk, B.D., Gorbovii, P.M., Baranovskii, V.S., and
Ganushchak, M.І., Zh. Org. Farm. Khіm., 2008, vol. 6,
no. 3(23), p. 16.
7. Ganushchak, N.I., Grishchuk, B.D., Tashchuk, K.G.,
Nemish, A.Yu., and Dombrovskii, A.V., Zh. Org.
Khim., 1972, vol. 8, no. 12, p. 2549.
8. Grishchuk, B.D., Doctoral (Chem.) Dissertation, Lviv,
1995.
9. Fedorovich, I.S., Obushak, N.D., Liakhovich, M.B., and
Ganushchak, N.I., Zh. Org. Khim., 1996, vol. 32, no. 3,
p. 400.
10. Ganushchak, N.I., Obushak, N.D., and Fedorovich, I.S.,
Ukr. Khim. Zh., 1987, vol. 53, no. 9, p. 970.
11. Grishchuk, B.D., Gorbovoi, P.M., Ganushchak, N.I.,
and Kudrk, E.Ya., Zh. Obshch. Khim., 1993, vol. 63,
no. 10, p. 2335.
3,3'-(4,4'-Diphenyl)bis(2-thiocyanatopropionamide)
(XIII) was prepared similarly from 2.8 g (0.04 mol) of
acrylamide, 1.4 g (0.004 mol) of copper(II) tetrafluoro-
borate hexahydrate, 4.0 g (0.041 mol) of potassium
thiocyanate, and 7.5 g (0.0195 mol) of 4,4'-diphenyl-
12. Baranovskii, V.S., Simchak, R.V., and Grishchuk, B.D.,
Russ. J. Gen. Chem., 2009, vol. 79, no. 2, p. 269.
13. Svoistva organicheskikh soedinenii (Properties of
Organic Compounds), Potekhin, A.A., Ed., Leningrad:
Khimiya, 1984, p. 120.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 83 No. 11 2013