Anionarylation of acrylic and methacrylic acids derivatives with p- and m-phenylenebisdiazonium tetrafluoroborates

Article abstract of DOI:10.1134/S1070363214080106

Chloro-, bromo- and thiocyanatoarylation of amides and nitriles of acrylic and methacrylic acids with bisdiazonium salts based on m- and p-phenylenediamines have been studied. 3,3'-[1,4(3)-phenylene]bis[2-halopropanamides(nitriles)] and 2-thiocyanato-(2-m

Full text of DOI:10.1134/S1070363214080106

ISSN 1070-3632, Russian Journal of General Chemistry, 2014, Vol. 84, No. 8, pp. 1505–1509. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © V.S. Baranovskii, V.N. Yatsyuk, B.D. Grishchuk, 2014, published in Zhurnal Obshchei Khimii, 2014, Vol. 84, No. 8, pp. 1279–1283.
Anionarylation of Acrylic and Methacrylic Acids Derivatives
with p- and m-Phenylenebisdiazonium Tetrafluoroborates
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 9, 2013
Abstract—Chloro-, bromo- and thiocyanatoarylation of amides and nitriles of acrylic and methacrylic acids
with bisdiazonium salts based on m- and p-phenylenediamines have been studied. 3,3'-[1,4(3)-phenylene]bis[2-
halopropanamides(nitriles)] and 2-thiocyanato-(2-methyl)-3-[4(3)-thiocyanatophenyl]propinamides have been
obtained as bishaloarylation and monothiocyanatoarylation products, respectively.
Keywords: anionarylation, phenylenebisdiazonium tetrafluoroborate, amide, nitrile of unsaturated acid
DOI: 10.1134/S1070363214080106
The Meerwein arylation and anionarylation with
bisdiazonium salts acting as arylation agent is a
convenient method of regioselective modification of
unsaturated compounds with one or two diazo groups
[1–5].
We found that reactions of p- and m-phenylene-
bisdiazonium tetrafluoroborates with acrylamide and
methacrylamide in the presence of thiocyanate anions
involved thiocyanatoarylation of one diazonium group
and nucleophilic substitution of the second one with
SCN to give compounds I–IV with yields of 44–63%
(Scheme 1).
Chloro-, bromo- and thiocyanatoarylation of
amides of acrylic and methacrylic acids with bisdia-
zonium tetrafluoroborates derived from benzidine,
diaminodiphenylmethane, or diaminodiphenylsulfone
involved the both diazo groups due to their spatial
accessibility [6].
Thiocyanatoarylation occurred in the 1 : 2.5 water–
acetone medium in the presence of catalytic amounts
of copper(II) tetrafluoroborate at –30 to –25°C. The
optimal ratio of phenylenebisdiazonium:amide:anion
reagent : catalyst was of 1.0 : 2.2 : 2.2 : 0.03. The reac-
tion was accompanied by formation of p- and m-dithio-
cyanatobenzenes in yields of 20–25% (with respect to the
diazonium salt) and resinous products of unknown structure.
In this work we further studied chloro-, bromo- and
thiocyanatoarylation of amides and nitriles of acrylic
and methacrylic acids with p- and m-phenylenebis-
diazonium tetrafluoroborates. We expected that using
those diazonium salts could significantly enhance the
anionarylation regioselectivity due to interaction
between the diazo groups via the conjugated molecule
fragment.
Changing the solvent nature (acetone, dimethyl-
formamide, acetonitrile, or their binary mixtures with
water), the reagents ratio (increasing amount of the
unsaturated substrate), and the sequence of the re-
agents mixing did not allow for thiocyanatoarylation at
the both diazonium groups.
Reactions of phenylenebisdiazonium tetrafluoroborates
with unsaturated compounds have been scarcely
reported in the literature. For instance, m-phenylene-
bisdiazonium tetrafluoroborate is known to react with
acrylonitrile, styrene, acrylates, and methacrylates in
the presence of NaCl and CuCl2. The major reaction
products correspond to chloroarylation of one of the
diazo groups accompanied by simultaneous
Sandmeyer substitution of the other group by chlorine.
In order to elucidate the effect of the anion
nucleophilicity on the anionarylation regioselectivity,
we studied chloro- and bromoarylation of amides and
nitriles of acrylic and methacrylic acids with phenyl-
enebisdiazonium tetrafluoroborates. The major reac-
tion direction was haloarylation of the both diazonium
moieties to form V–XVI (Scheme 2).
1505

1506
BARANOVSKII et al.
Scheme 1.
N2BF4
N2BF4
R
NCS
O
−N2, −KBF4
R
NH
N2BF4
SCN
2
I, II
NH2
+ KSCN
O
N2BF4
R
NH2
−N2, −KBF4
O
NCS
SCN
III, IV
R = H (I, III), CH3 (II, IV).
Scheme 2.
N2BF4
X
HLg
R
N2BF4
−N2, −MBF4
R
Hlg
X
R
V−XII
+ MHlg
N2BF4
R
X
X
N2BF4
−N2, −MBF4
HLg
R
X
Hlg
XIII−XVI
Hlg = Cl (V–VIII, XIII, XІV), Br (IX–XIІ, XV, XVI); X = C(O)NH2 (V, VI, IX, X, XIII–XVI), CN (VII, VIII, XI, XII);
R = H (V, VII, IX, XI, XIII, XV), CH3 (VI, VIII, X, XII, XIV, XVI).
1
The reactions occurred in the 1 : 2.5 water–acetone
medium at 0–25°C in the presence of sodium chloride
or potassium bromide, with copper(II) tetrafluoro-
borate as the catalyst. Yield of the bishaloamides and -
nitrites were of 20–63%. Further reaction products
were p- and m-dichloro(bromo)benzenes with yield of
up to 40%.
than 5%, H NMR), nucleophilic substitution of the
diazonium group with chlorine or bromine being the
main reaction pathway. Under the conditions tested,
substantial resinification was observed, caused appar-
ently by polymerization of the unsaturated nitriles.
Yield of the chloro-, bromo-, and thiocyanatoaryla-
tion products I–XVI increased as the anion nuc-
leophilicity increased in the Cl < Br < SCN series.
Yields, melting points, and H NMR features of
compounds I–XVI are collected in Tables 1 and 2.
The reactions of m-phenylenebisdiazonium tetra-
fluoroborate with acrylonitrile and methacrylonitrile
yielded only traces of the target bishalonitriles (less
1
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ANIONARYLATION OF ACRYLIC AND METHACRYLIC ACIDS DERIVATIVES
1507
S
Table 1. Yield, melting point, and elemental analysis data of compounds I–XVI
Found, %
Cl(Br)
Calculated, %
Yield, mp,
%
An
X
Ar
R
Formula
°Cа
N
S
N
Cl(Br)
I
SCN CONH2 p-С6Н4
H
51
63
40
44
24
29
25
20
43
51
38
43
23
27
35
42
148 16.07
151 15.23
119 15.86
128 15.21
–
–
–
–
24.41 C11H9N3OS2
23.07 C12H11N3OS2
24.28 C11H9N3OS2
23.19 C12H11N3OS2
15.96
15.15
15.96
15.15
–
–
–
–
24.35
II
SCN CONH2 p-С6Н4 CH3
23.12
III SCN CONH2 m-С6Н4
IV SCN CONH2 m-С6Н4 CH3
Cl CONH2 p-С6Н4
CONH2 p-С6Н4 CH3
H
24.35
23.12
V
H
185
194
9.60 24.60
8.92 22.47
–
–
–
–
–
–
–
–
–
–
–
–
C12H14Cl2N2O2
C14H18Cl2N2O2
C12H10Cl2N2
9.69 24.52
8.83 22.35
11.07 28.01
9.96 25.22
7.41 42.27
6.90 39.35
8.19 46.72
7.57 43.18
9.69 24.52
8.83 22.35
7.41 42.27
6.90 39.35
–
–
–
–
–
–
–
–
–
–
–
–
VI Cl
VII Cl
VIII Cl
IX Br
CN
CN
p-С6Н4
H
180 11.00 28.12
172 10.01 25.13
p-С6Н4 CH3
C14H14Cl2N2
CONH2 p-С6Н4
H
198
205
178
169
177
161
153
163
7.49 42.36
6.93 39.47
8.14 46.77
7.64 43.12
9.62 24.59
8.80 22.36
7.34 42.36
6.95 39.30
C12H14Br2N2O2
C14H18Br2N2O2
C12H10Br2N2
X
Br
CONH2 p-С6Н4 CH3
XI Br
XII Br
XIII Cl
XIV Cl
XV Br
XVI Br
CN
CN
p-С6Н4
H
p-С6Н4 CH3
C14H14Br2N2
CONH2 m-С6Н4
CONH2 m-С6Н4 CH3
CONH2 m-С6Н4
CONH2 m-С6Н4 CH3
H
C12H14Cl2N2O2
C14H18Cl2N2O2
C12H14Br2N2O2
C14H18Br2N2O2
H
a Recrystallized from methanol.
Structures of I–XVI were confirmed by IR and
NMR spectroscopy data. IR spectra of halo(thio-
cyanato)amides I–VI, IX, X, and XIII–XVI contained
characteristic absorption bands of carbonyl (1652–
1688 cm–1) and amide (3374–3404 cm–1) groups. In the
spectra of thiocyanatoamides I–IV, absorption band of
thiocyanate stretching was observed as well at 2152–
2168 cm–1. Absorbance bands at 2224–2236 cm–1
observed in the spectra of VII, VIII, XI, and XII were
assigned to nitrile group.
1H NMR spectra of adducts I–XVI contained
signals of the aromatic protons (7.63–7.04 ppm). In the
cases of derivatives of acrylamide and acrylonitrile,
protons of methylene groups adjacent to aromatic rings
resonated at 3.40–3.13 and 3.29–2.99 ppm as two
doublets of doublets. In the spectra of methacrylamide
and methacrylonitrile derivatives, two doublets of me-
thylene protons appeared in the range of 3.50–3.16 ppm.
Protons of methine groups adjacent to chlorine,
bromine, or thiocyanate group were observed as
triplets at 4.57–4.19 ppm (5.54–5.37 ppm in the cases
of acrylonitrile derivatives). Singlets at 1.91–1.72 ppm
were assigned to methyl protons of methacrylate fragment.
To conclude, bisdiazonium salts prepared from p-
and m-phenylenediamines are highly reactive in the
studied anionarylation reactions. In contrast to
diphenylbisdiazonium tetrafluoroborates, they are
more reactive towards nucleophilic substitution of the
diazonium group, especially in the case of strong
nucleophiles, such as thiocyanate anion. Furthermore,
the Sandmeyer reaction and anionarylation occur under
similar conditions, and it is possible to combine these
processes using one and the same arylating agent.
EXPERIMENTAL
IR spectra (Vaseline oil) were recorded using the
1
Specord M80 instrument. H NMR spectra (DMSO-d6
or CDCl3; TMS as internal reference) were registered
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 84 No. 8 2014

1508
BARANOVSKII et al.
Table 2. 1Н NMR spectral data (δ, ppm, J, Hz) of compounds I–XVI
Comp. no.
Ar
NН2
CH2Ar
R
І
7.59 d (J 8), 7.35 d (J 8)
8.00 s, 7.76 c
3.39 d.d (J 12.4), 3.07 d.d (J
14.2)
4.25 t (J 11.6)
ІІ
7.63 d (J 8), 7.38 d (J 8)
8.18 s, 7.93 s
3.50 d (J 14.8), 3.16 d (J 14.4)
1.84 s
ІІІ
7.44 d (J 8), 7.39–7.34 m, 7.27 d (J 8) 6.01 s, 5.78 s
3.23 d.d (J 12.8), 2.99 d.d (J
14.0)
4.19 t (J 12.2)
IV
7.48 d (J 8), 7.44–7.38 m, 7.32 d (J
6.07 s, 5.88 s
3.38 d (J 14.0), 3.31 d (J 14.4)
1.80 s
7.6)
V
7.54 d (J 8.2), 7.29 d (J 8)
7.18 s
7.73 s, 7.36 s
7.52 s, 7.45 s
–
3.18 d.d (J 12.2), 3.10 d.d (J 14.4) 4.57 t (J 11.8)
3.27 d (J 14.2), 3.20 d (J 14.0) 1.90 s
3.37 d.d (J 14.4), 3.20 d.d (J 12.6) 5.54 t (J 11.2)
3.34 d (J 14.2), 3.25 d (J 13.8) 1.91 s
3.13 d.d (J 14.0), 3.06 d.d (J 13.8) 4.51 t (J 11.4)
3.50 d (J 13.0), 3.18 d (J 13.4) 1.84 s
3.40 d.d (J 14.2), 3.29 d.d (J 13.8) 5.37 t (J 12.2)
3.45 d (J 14.0), 3.36 d (J 14.0) 1.78 s
3.30 d.d (J 13.2), 3.21 d.d (J 14.0) 4.52 t (J 11.8)
3.50 d (J 14.0), 3.35 d (J 14.4) 1.86 s
3.24 d.d (J 14.2), 3.17 d.d (J 14.2) 4.48 t (J 12.2)
3.47 d (J 13.8), 3.33 d (J 14.0) 1.72 s
VI
VII
VIII
IX
7.43 d (J 8.4), 7.37 d (J 8)
7.36 s
–
7.50 d (J 8), 7.22 d (J 8)
7.60 d (J 8.2), 7.36 d (J 7.8)
7.36 s
7.66 s, 7.24 s
8.16 s, 7.93 s
–
X
XI
XII
XIII
XIV
XV
XVI
7.49 d (J 7.6), 7.25 d (J 8)
7.29–7.09 m
–
7.49 s, 7.36 s
7.66 s, 7.52 s
7.52 s, 7.27 s
7.60 s, 7.42 s
7.31–7.18 m
7.22–7.04 m
7.27–7.11 m
with the Varian Mercury (400 MHz) spectrometer.
TLC was performed on Silufol UV-254 plates eluting
with benzene–methanol (4 : 1) or methanol–benzene–
acetone (1: 3: 1) mixture.
recrystallized from methanol. Yield 2.4 g (51%).
Additionally, 1.1 g (21%) of p-dithiocyanatobenzene
(mp 93°C) was isolated.
Thiocyanatoamides II–IV were prepared similarly.
2-Thiocyanato-3-(4-thiocyanatophenyl)propion-
amide (I). p-Phenylenebisdiazonium tetrafluoroborate
(5.6 g, 0.018 mol) was added to a mixture of 2.85 g
(0.04 mol) of acrylamide, 0.2 g (0.0005 mol) of copper
(II) tetrafluoroborate hexahydrate and 3.9 g (0.04 mol)
of potassium thiocyanate in 100 mL of the 1 : 2.5
water–acetone mixture over 1.5 h. Nitrogen evolution
was observed at –20 to –23°C for 60 min. After
nitrogen evolution ceased, 30 mL of water was added
to the reaction mixture, and the mixture was extracted
with 50 mL of diethyl ether. The extracts were washed
with water, dried with anhydrous calcium chloride, and
evaporated. The residue was incubated at –20°C until
its complete solidification. The resulting solid was
3,3'-(1,4-Phenylene)bis(2-chloropropanamide)
(V). p-Phenylenebisdiazonium tetrafluoroborate (5.6 g,
0.018 mol) was added to a mixture of 2.85 g (0.04 mol)
of acrylamide, 0.2 g (0.0005 mol) of copper(II)
tetrafluoroborate hexahydrate, and 2.35 g (0.04 mol) of
sodium chloride in 100 mL of the 1 : 2.5 water–acetone
mixture over 2 h. Nitrogen evolution was observed at
20–25°C during 3 h. After nitrogen evolution ceased,
50 mL of water was added to the reaction mixture, and
the mixture was extracted with 75 mL of diethyl ether.
The extracts were washed with water, dried with
anhydrous calcium chloride, and evaporated. The
residue was incubated at –20°C until its complete
solidification. The resulting solid was recrystallized
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ANIONARYLATION OF ACRYLIC AND METHACRYLIC ACIDS DERIVATIVES
1509
from methanol. Yield 1.0 g (24%). Additionally, 0.7 g
REFERENCES
(27%) of p-dichlorobenzene {mp 53°C (mp 54°C [8])}
1. Dombrovskii, A.V., Russ. Chem. Rev., 1984, vol. 53,
was isolated.
no. 10, p. 943.
3,3'-(1,4-Phenylene)bis(2-bromopropanamide)
(IX). p-Phenylenebisdiazonium tetrafluoroborate
(5.6 g, 0.018 mol) was added to a mixture of 2.85 g
(0.04 mol) of acrylamide, 0.2 g (0.0005 mol) of cop-
per(II) tetrafluoroborate hexahydrate, and 4.75 g
(0.04 mol) of potassium bromide in 100 mL of the
1 : 2.5 water–acetone (1 : 2.5) mixture over 2 h.
Nitrogen evolution was observed at 0–10°C during 2 h.
After nitrogen evolution ceased, 50 mL of water was
added to the reaction mixture, and the mixture was
extracted with 50 mL of diethyl ether. The extracts
were washed with water, dried with anhydrous calcium
chloride, and evaporated. The residue was incubated at
–20°C until its complete solidification. The resulting
solid was recrystallized from methanol. Yield 2.9 g
(43%). Additionally, 1.4 g (32%) of p-dibromobenzene
{mp 87°C (mp 87.5°C [8])} was isolated.
2. Grishchuk, B.D., Gorbovoi, P.M., Ganushchak, N.I.,
and Dombrovskii, A.V., Russ. Chem. Rev., 1994, vol. 63,
no. 3, p. 257.
3. Grishchuk, B.D., Gorbovii, P.M., Baranovs’kii, V.S.,
and Ganushchak, М.І., Zh. Org. Farm. Khim., 2008,
vol. 6, no. 3(23), p. 16.
4. Ganushchak, N.І., Grishchuk, B.D., Tashchuk, K.G.,
Nemish, A.Yu., and Dombrovskii, A.V., Zh. Org.
Khim., 1972, vol. 8, no. 12, p. 2549.
5. Grishchuk, B.D., Doctoral (Chem.) Dissertation, Lviv,
1995.
6. Baranovskii, V.S., Yatsyuk, V.N., and Grishchuk, B.D.,
Russ. J. Gen. Chem., 2013, vol. 83, no. 11, p. 2040.
7. Obushak, N.D., Ganushchak, N.I., Lesyuk, A.I., Pil’o, S.G.,
Demchuk, O.M., and Mazyar, L.P., Zh. Org. Khim.,
1997, vol. 33, no. 4, p. 490.
8. Svoistva organicheskikh soedinenii (Properties of
Organic Compounds), Potekhin, A.A., Ed., Leningrad:
Khimiya, 1984.
Bishaloamides VI, X, XIII–XVI and bishalonitriles
VII, VIII, XI, XII were prepared similarly.
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