Successive reaction of 2-aryl-4-dichloromethylideneoxazol-54H-ones with 2-amino-1,3-thiazoles and strongly basic nitrogen-containing reagents

Article abstract of DOI:10.1134/S1070363208040221

Treatment of 2-aryl-4-dichloromethylideneoxazole-5(4H)-ones first with 2-aminothiazoles and then with benzylamine, piperidine, or morpholine gave the corresponding 5-amino-4-(1,3-thiazol-2-ylcarbamoyl)-1,3-oxazole derivatives whose structure was confirmed by a combination of spectral data and X-ray analysis.

Full text of DOI:10.1134/S1070363208040221

ISSN 1070-3632, Russian Journal of General Chemistry, 2008, Vol. 78, No. 4, pp. 649–654. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © V.M. Prokopenko, V.N. Sviripa, V.S. Brovarets, E.B. Rusanov, B.S. Drach, 2008, published in Zhurnal Obshchei Khimii, 2008,
Vol. 78, No. 4, pp. 668–673.
Successive Reaction of 2-Aryl-4-dichloromethylideneoxazol-
54H-ones with 2-Amino-1,3-thiazoles and Strongly Basic
Nitrogen-containing Reagents
V. M. Prokopenkoa, V. N. Sviripaa, V. S. Brovaretsa, E. B. Rusanovb, and B. S. Dracha
a Institute of Bioorganic and Petroleum Chemistry, National Academy of Sciences of Ukraine,
ul. Murmanskaya 1, Kiev, 02660 Ukraine
e-mail: drach@bpci.kiev.ua
b Institute of Organic Chemistry, National Academy of Sciences of Ukraine,
ul. Murmanskaya 5, Kiev, 02660 Ukraine
Received August 17, 2007
Abstract—Treatment of 2-aryl-4-dichloromethylideneoxazole-5(4H)-ones first with 2-aminothiazoles and then
with benzylamine, piperidine, or morpholine gave the corresponding 5-amino-4-(1,3-thiazol-2-ylcarbamoyl)-
1,3-oxazole derivatives whose structure was confirmed by a combination of spectral data and X-ray analysis.
DOI: 10.1134/S1070363208040221
1
Accessible chlorine-containing unsaturated azlacto-
nes I are multicenter electrophilic compounds capably
of reacting with soft and hard bases in different ways
to produce a number of functionally substituted
heterocycles [1–12]. We now report for the first time
on the reaction of compounds I with 2-amino-1,3-
thiazole and its analogs, 2-amino-4-phenyl-1,3-
thiazole, 2-amino-4,5-dimethyl-1,3-thiazole, 2-amino-
benzothiazole, and 2-amino-6-methylbenzo-thiazole.
In all cases, the primary amino group in the thiazole
derivatives attacks the C5 atom of the oxazole ring in
compounds I, leading to the formation of enamides II
and III via opening of the oxazole ring. As a rule, such
enamides can be isolated individual (Scheme 1, Table 1).
However, we failed to isolate primary products of the
reactions of Ia and Ib with 2-amino-1,3-thiazole, for
they readily underwent intramolecular cyclization into
fused imidazothiazoles IVa and IVb, respectively.
the H NMR spectra which contained a characteristic
signal at δ 6.51–6.61 ppm.
Introduction of a substituent into the 4-position of
the thiazole ring in structure A is likely to create steric
hindrances to intramolecular cyclization; therefore,
primary products of the reactions of I with 2-amino-4-
phenyl-1,3-thiazole,
2-amino-4,5-dimethyl-1,3-thia-
zole, 2-amino-1,3-benzothiazole, and 2-amino-6-
methyl-1,3-benzothiazole can be isolated with no
difficulties. The structure of enamides II and III was
confirmed by spectral data and chemical methods.
Comparison of the IR spectra of compounds I–III
showed that the oxazole ring is opened in the early
reaction; this follows from disappearance of carbonyl
absorption typical of oxazolone carbonyl group (1790–
1800 cm–1; Table 2) from the IR spectra. On the other
hand, the structure of compounds II and III as
representatives of a broad series of chlorine-containing
enamides with the general formula Cl2C=C(X)
NHCOR, where X is an electron-withdrawing group, is
Presumably, the cyclization involves prototropic
tautomers of IIa and IIb possessing clearly electron-
deficient N-acylimino group which is capable of
interacting with the lone electron pair on the nitrogen
atom in the thiazole ring (transformation sequence
A→B→C in Scheme 2. The presence of a
dichloromethyl substituent in structure C follows from
confirmed
by their cyclocondensation with
benzylamine, piperidine, and morpholine (trans-
formations II→V→III→VI in Scheme 1). These
cyclizations may be regarded as particular cases of the
general synthesis of 5-amino-1,3-oxazole derivatives
from chlorine-containing enamides [13].
649

650
PROKOPENKO et al.
Scheme 1.
Cl
Cl
N
Ar
O
O
Iа, Ib
R1
R2
N
S
N
S
NH2, Et3N
NH2, Et3N
R3
Δ
Δ
O
Cl
O
Cl
R1
N
S
N
S
N
H
Cl
O
N
H
Cl
R2
R3
N
N
O
O
H
H
Ar
Ar
H
IIIа−IIIc
IIа−IIf
Ar
N
CHCl2
O
R1 = R2 = H
N
R4R5NH (excess)
N
S
R4R5NH (excess)
IVа, IVb
R4R5NH (excess)
O
O
R1
R2
NR4R5
NR4R5
N
S
N
S
N
H
N
H
R3
N
O
N
O
Ar
Ar
Vа−Vm
VIа−VId
Ia, IIa, IIc, IIe, IIIa, IIIb, IVa, Va, Vc, Ve, Vg, Vi, Vk, Vm, VIa, VIb, Ar = Ph; Ib, IIb, IId, IIf, IIIc, IVb, Vb, Vd, Vf, Vh, Vj, Vl;
VIc, VId, Ar = 4-MeC6H4; IIa, IIb, Va–Vd, R1 = R2 = H; IIc, IId, Ve–Vh, R1 = Ph, R2 =H; IIe, IIf, Vi–Vm, R1 = R2 = Me; IIIa, VIa, R3 =
H; IIIb, IIIc; VIb–VId, R3 = Me; Va, Vb, Ve, Vf, Vi, Vj, R4R5N = piperidino; Vc, Vd, Vg, Vh, Vk, Vl, VIa–VIc, R4R5N = morpholino;
Vm; VId, R4 = H, R5 = PhCH2.
Table 1. Yields, melting points, and elemental analyses of compounds II–VI
Found, %
Calculated, %
Cl (S)
Comp.
no.
mp, °С
Yield, %
Formula
(solvent)
Cl (S)
N
N
50
50
46
61
50
57
47
58
71
184–185 (EtOH)
190–192 (EtOH)
195–196 (AcOH)
181–182 (AcOH)
212–213 (AcOH)
177–178 (EtOH)
192–193 (CH3CN)
241–243 (DMF)
196–197 (CH3CN)
16.15
16.38
19.49
18.38
17.95
16.95
16.84
20.56
19.84
10.28
9.70
С19H13Cl2N3O2S
С20H15Cl2N3O2S
С15H13Cl2N3O2S
С16H15Cl2N3O2S
С17H11Cl2N3O2S
С18H13Cl2N3O2S
С19H15Cl2N3O2S
С13H9Cl2N3O2S
С14H11Cl2N3O2S
16.95
16.40
19.15
18.45
18.08
17.45
16.87
20.72
19.90
10.05
9.72
IIc
IId
IIe
10.32
10.49
11.14
10.10
9.97
11.35
10.93
10.71
10.34
10.00
12.28
11.80
IIf
IIIа
IIIb
IIIc
IVa
IVb
12.41
11.36
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 4 2008

SUCCESSIVE REACTION OF 2-ARYL-4-DICHLOROMETHYLIDENEOXAZOL-5(4H)-ONES
Table 1. (Contd.)
651
Found, %
Calculated, %
Cl (S)
Comp.
no.
mp, °С
Yield, %
Formula
(solvent)
Cl (S)
N
N
70
66
66
41
60
46
52
61
66
55
68
48
54
61
64
64
50
188–190 (DMF)
181–182 (DMF)
228–229 (DMF)
247–248 (DMF)
197–198 (CH3CN)
204–205 (CH3CN)
227–228 (CH3CN)
225–226 (CH3CN)
205–206 (EtOH)
231–232 (EtOH)
198–199 (EtOH)
234–235 (EtOH)
188–189 (i-PrOH)
251–252 (AcOH)
252–253 (AcOH)
240–241 (AcOH)
212–213 (EtOH)
(9.14)
(8.59)
(8.87)
(8.48)
(7.30)
(7.59)
(7.22)
(7.34)
(8.53)
(8.21)
(8.38)
(7.40)
(7.72)
(8.12)
(7.61)
(7.16)
(7.42)
15.68
15.06
15.55
14.92
12.55
11.96
11.97
12.39
14.48
13.43
14.68
12.52
13.25
13.56
12.81
12.10
12.19
С18H18N4O2S
С19H20N4O2S
С17H16N4O3S
С18H18N4O3S
С24H22N4O2S
С25H24N4O2S
С23H20N4O3S
С24H22N4O3S
С20H22N4O2S
С21H24N4O2S
С19H20N4O3S
С20H22N4O3S
С22H20N4O2S
С21H18N4O3S
С22H20N4O3S
С23H22N4O3S
С26H22N4O2S
(9.05)
(8.70)
(8.99)
(8.66)
(7.45)
(7.21)
(7.41)
(7.18)
(8.38)
(8.09)
(8.34)
(8.05)
(7.93)
(7.89)
(7.63)
(7.38)
(7.05)
15.81
15.21
15.72
15.13
13.01
12.60
12.95
12.55
14.65
14.13
14.57
14.06
13.85
13.78
13.32
12.89
12.33
Va
Vb
Vc
Vd
Ve
Vf
Vg
Vh
Vi
Vj
Vk
Vl
Vm
VIа
VIb
VIc
VId
It is interesting that treatment of fused heterocyclic
compounds IV with nitrogen bases also leads to the
formation of analogous 1,3-oxazole derivatives. For
example, by heating compound IVa (Ar = Ph) with
morpholine we obtained 5-morpholino-2-phenyl-N-
(1,3-thiazol-2-yl)-1,3-oxazole-4-carboxamide (Vc) whose
structure was unambiguously determined by X-ray
analysis. The general view of molecule Vc is shown in
figure, and its principal geometric parameters are
collected in Table 3.
Scheme 2.
O
O
Cl
Cl
O
Cl
N
H
Cl
O
H
H
H
N
N
Cl
O
Cl
S
N
O
N
HN
N
H
S
N
S
N
C
А
B
−Η, Δ
N
N −Η
−Η
N
N +
Cl−
O
O
O
H
N
H
H
N
Cl
O
N
2
−Η
N
2
−Η
N
N
Cl
O
N
O
HN
S
N
S
N
N
S
N
F
D
E
N = piperidino, morpholino, PhCH2NH.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 4 2008

652
PROKOPENKO et al.
Table 2. Spectral parameters of some compounds II–VI
Table 3. Principal bond lengths (d) and bond angles (ω) in
the molecule of 5-morpholino-2-phenyl-N-(1,3-thiazol-2-
yl)-1,3-oxazole-4-carboxamide (Vc)
Comp.
1H NMR spectrum (DMSO-d6), δ, ppm
no.
Bond
d
Bond angle
ω
C1–C2
C1–S1
C2–N1
C3–N1
C3–S1
C3–N2
C4–N2
C4–C5
C5–C6
C5–N3
C6–O2
C7–N3
C7–O2
1.328(3)
1.711(2)
1.375(2)
1.3058(19)
1.7205(17)
1.378(2)
1.370(2)
1.447(2)
1.381(2)
1.398(2)
1.367(2)
1.289(2)
1.3798(18)
C2C1S1
C1C2N1
N1C3N2
N1C3S1
N2C3S1
N2C4C5
C6C5N3
C6C5C4
N3C5C4
O2C6C5
N3C7O2
110.98(16)
116.09(17)
121.10(15)
115.67(13)
123.23(12)
114.99(14)
108.15(14)
130.75(14)
120.90(13)
107.39(13)
113.01(14)
2.40 s (3H, CH3), 7.28–7.42 m (5H, C6H5), 7.55 s (1H, 5-
H), 7.88–7.90 m (4H, Harom), 10.17 s (1H, NH), 12.93 s
(1H, NH)
IId
2.18–2.40 m (9N, 3CH3), 7.30–7.84 m (4H, Harom), 10.10
s (1H, NH), 12.46 s (1H, NH)
IIf
6.61 s (1H, CHCl2), 7.02–7.85 m (5H, Harom, 2-H, 3-H),
9.67 s (1H, NH)
IVa
IVba
Vab
Vbb
2.39 s (3H, CH3), 6.51 s (1H, CHCl2), 6.97 d, 7.55 d (2H,
2-H, 3-H), 7.29 d, 7.72 d (4H, Harom), 9.41 s (1H, NH)
1.65 s, 3.77 s [10H, (CH2)5N., 7.19–7.92 m (5H, Harom, 4-
H, 5-H), 10.81 s (1H, NH)
1.65 s, 3.77 s [10H, (CH2)5N., 2.36 s (3H, CH3), 7.18 d,
7.49 d (2H, 4-H, 5-H), 7.32 d (2H, Harom), 7.85 d (2H,
Harom), 10.78 s (1H, NH)
Vcb
Vdb
3.80 m [8H, O(CH2)4N., 7.21–7.98 m (5H, Harom, 4-H, 5-
H), 11.07 s (1H, NH)
Taking into account similarity of the spectral data
of compounds V and VI (Table 2), we can contend
with certainty that they have the structure of 5-amino-
1,3-oxazole derivatives having an N-substituted
carboxamide group on C4 due to regioselective
cleavage of the oxazole ring in I by the primary amino
group in 1,3-thiazole bases.
2.37 c (3H, CH3), 3.79 m [8H, O(CH2)4N., 7.20 d, 7.49 d
(2H, 4-H, 5-H), 7.33 d (2H, Harom), 7.87 d (2H, Harom),
10.83 s (1H, NH)
1.64 s, 3.76 s [10H, (CH2)5N., 2.36 s (3H, CH3), 7.33–
7.43 m (5H, C6H5), 7.58 s (1H, 5-H), 7.85–7.93 m (4H,
Harom), 10.82 s (1H, NH)
Vf
Vhc
2.38 s (3H, CH3), 3.81 m [8H, O(CH2)4N], 7.34–7.44 m
(5H, Harom), 7.64 s (1H, 5-H), 7.97 m (4H, Harom), 11.12 s
(1H, NH)
The subsequent transformations of enamides A are
illustrated by Scheme 2. It should be noted that the
first stages of the transformation A→B→C resemble
cycloaddition of benzamidine to compounds I [12].
However, cycloaddition products derived from
benzamidine are converted into pyrimidine derivatives
2.37 s, 2.43 s (6H, 2CH3), 2.98 m (2H, CH2), 7.26–7.73
m (12H, Harom), 8.48 m (1H, NH), 10.90 s (1H, NH)
VIg
a
IR spectrum, ν, cm–1: 1675 (NC=O), 1725 (C=O), 3050–3450
b
(N–Has).
IR spectrumy, ν, cm–1: 1660 (NC=O), 3170–3450
(N–Has). c IR spectrum, ν, cm–1: 1675 (NC=O), 3380 (N–H).
C11
C12
C10
C13
N1
C9
C2
N3
C6
The oxazole ring in molecule Vc is almost planar:
the mean-square deviation of atoms from the
corresponding plane is 0.008 Å. The benzene ring C8–
C13 is turned by 18.1°, and the thiazole ring, by 10.6°
with respect to the oxazole ring. The sum of the bond
angles at N2 is 360°, and the C3–N2 and C4–N2 bonds
[1.378(2) and 1.370(2) Å, respectively] are shorter
than the standard single C–N bond (1.45 Å), indicating
conjugation between the lone electron pair on N2 and π
systems of the tiazole ring and carbonyl group. The
C4–C5 bond is also slightly shortened as a result of
effective conjugation between the oxazole and thiazole
rings.
C7 C8
C3
C1
C5
C4
N2
O1
O2
S1
N4
C18
C16
C14
C15
O3
Structure of the molecule of 5-morpholino-2-phenyl-N-(1,3-
thiazol-2-yl)-1,3-oxazole-4-carboxamide (Vc) according to
the X-ray diffraction data.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 4 2008

SUCCESSIVE REACTION OF 2-ARYL-4-DICHLOROMETHYLIDENEOXAZOL-5(4H)-ONES
653
on heating with morpholine or piperidine [14], while
compounds C react with nitrogen bases according to
the scheme C → A → D → E or C → F → E.
Although it is difficult to choose between these
alternative pathways, the final products are the same 5-
amino-4-carbamoyl-1,3-oxazole derivatives. Additional
studies are necessary to elucidate the reasons for the
different reactivities of the cycloaddition products of
benzamidine and 2-amino-1,3-thiazoles to compounds
I; nevertheless, the basicity of reagents having a –C
(NH2)=N– fragment is likely to be important in both
cases.
with I >2σ(I); GOF 1.017]. The residual electron
density from the Fourier difference series after the last
iteration cycle was 0.23 and –0.19 e Å–3.
N-[2,2-Dichloro-1-(4-phenyl-1,3-thiazol-2-ylcar-
bamoyl)vinyl]benzamides IIc and IId (general
procedure). A mixture of 0.008 mol of compound Ia
and Ib, 0.008 mol of 4-phenyl-1,3-thiazol-2-2-amine,
and 0.008 mol of triethylamine in 20 ml of THF was
heated for 7 h under reflux. After cooling, the
precipitate of triethylamine hydrochloride was filtered
off, the filtrate was evaporated under reduced pressure,
the residue was treated with water, and the precipitate
was filtered off and purified by recrystallization.
N-[2,2-Dichloro-1-(4,5-dimethyl-1,3-thiazol-2-yl-
carbamoyl)vinyl]benzamides IIe and IIf (general
procedure). A mixture of 0.008 mol of compound Ia or
Ib, 0.008 mol of 4,5-dimethyl-1,3-thiazol-2-amine
hydrochloride, and 0.016 mol of triethylamine in 20 ml
of THF was heated for 7 h. The mixture was cooled,
and the precipitate was filtered off and purified by
recrystallization.
EXPERIMENTAL
The IR spectra were recorded on a Specord M-80
spectrometer from samples prepared as KBr pellets.
1
The H NMR spectra were measured on a Varian
VXR-300 instrument from solutions in DMCO-d6
using tetramethylsilane as internal reference.
X-Ray analysis of compound Vc. The X-ray
diffraction data for a 0.15×0.25×0.50-mm single
crystal of compound Vc were obtained on a Bruker
Smart Apex II diffractometer (λMoKα irradiation,
graphite monochromator, θmax 26.54°, spherical
segment –10 ≤ h ≤ 10, –11 ≤ k ≤ 12, –24 ≤ l ≤ 26).
Monoclinic crystals, space group P21/c (no. 14);
C17H16N4O3S; M 356.40; a = 8.1763(3), b = 9.5996(3),
c = 20.8397(6) Å; β = 90.729(2)°; V = 1635.56(9) Å3;
Z = 4; dclac = 1.447 g/cm3; μ = 0.223 mm–1; F(000) =
744. Total of 12046 reflections were collected, 3682 of
which were independent (averaging factor R = 0.0275).
The structure was solved by the direct method and was
refined by the least-squares procedure in full-matrix
anisotropic approximation using SHELXS-97 and
SHELXL-97 software packages [15, 16]. The
refinement procedure was performed using 2821
reflections with I > 2σ(I) (290 refined parameters,
9.73, reflections per parameter) and the weight scheme
ω = 1/[σ2(Fo2) + (0.0580P)2 + 0.2891R], where R =
(Fo2 + 2Fc2)/3; the ratio of the maximal (average)
displacement to the error in the last cycle was 0.016
(0.002). A correction for absorption was intriduced
using SADABS program (the minimal-to-maximal
correction ratio was Tmin/Tmaks = 0.844037). All
hydrogen atoms were visualized objectively from the
Fourier difference series, and their positions were
refined in isotropic approximation. The final
divergence factors were R1(F2) = 0.0557, = RW(F2)
0.1114 (for all independent reflections; GOF 1.017)
and R1(F) = 0.0394, RW(F2) = 0.1016 [for reflections
N-[1-(1,3-Benzothiazol-2-ylcarbamoyl)-2,2-di-
chlorovinyl]benzamide (IIIa). A mixture of 0.008
mol of compound Ia, 0.008 mol of 1,3-benzothiazol-2-
amine, and 0.008 mol of triethylamine in 20 ml of THF
was heated for 7 h under reflux. After cooling, the
precipitate of triethylamine hydrochloride was filtered
off, the filtrate was evaporated under reduced pressure,
the residue was treated with water, and the precipitate
was filtered off and purified by recrystallization.
N-[2,2-Dichloro-1-(6-methyl-1,3-benzothiazol-2-
ylcarbamoyl)vinyl]benzamides IIIb and IIIc were
synthesized in a similar way from compounds Ia and
Ib, respectively, and 6-methyl-1,3-benzothiazol-2-
amine.
N-(5-Dichloromethyl-6-oxo-5,6-dihydroimidazo-
[2,1-b]thiazol-5-yl)benzamides IVa and IVb (general
procedure). A mixture of 0.04 mol of compound Ia and
Ib, 0.04 mol of 1,3-thiazol-2-amine, and 0.04 mol of
triethylamine in 90 ml of THF was heated for 7 h
under reflux. The precipitate was filtered off and
purified by recrystallization.
2-Aryl-5-piperidino(morpholino)-N-(1,3-thiazol-
2-yl)-1,3-oxazole-4-carboxamides Va–Vd (general
procedure). A mixture of 0.003 mol of compound IVa
and IVb and 0.012 mol of piperidine or morpholine in
5 ml of pyridine was heated for 4 h under reflux. The
mixture was cooled, 10 ml of 5% hydrochloric acid
was added, and the precipitate was filtered off and
purified by recrystallization.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 4 2008

654
PROKOPENKO et al.
Org. Khim., 1978, vol. 14, no. 3, p. 508.
2-Aryl-5-piperidino(morpholino)-N-(4-p h e n y l -
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5. Vinogradova, T.K., Mis’kevich, G.N., and Drach, B.S.,
1,3-thiazol-2-yl)-1,3-oxazole-4-carboxamides Ve–Vh
(general procedure). A mixture of 0.005 mol of
compound IIc or IId and 0.02 mol of piperidine or
morpholine in 10 ml of pyridine was heated for 4 h
under reflux. The mixture was cooled, 15 ml of 5%
hydrochloric acid was added, and the precipitate was
filtered off and purified by recrystallization.
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Zyuz’, K.V., Chernega, A.N., and Drach, B.S., Russ. J.
Gen. Chem., 2004, vol. 74, no. 9, p. 1328.
2-Aryl-N-(4,5-dimethyl-1,3-thiazol-2-yl)-5-piper-
idino(morpholino)-1,3-oxazole-4-carboxamides Vi–
Vl were synthesized in a similar way from enamides
IIe and IIf.
5-Benzylamino-N-(4,5-dimethyl-1,3-thiazol-2-yl)-
2-phenyl-1,3-oxazole-4-carboxamide (Vm) was
synthesized in a similar way from enamide IIe and
benzylamine.
9. Sviripa, V.N., Prokopenko, V.M., Brovarets, V.S., and
Drach, B.S., Zh. Org. Fiz. Khim., 2004, vol. 2, no. 4, p. 43.
10. Sviripa, V.N., Brovarets, V.S., and Drach, B.S., Russ. J.
Gen. Chem., 2004, vol. 74, no. 4, p. 639.
2-Aryl-N-(1,3-benzothiazol-2-yl)-5-morpholino
11. Sviripa, V.N., Brovarets, V.S., and Drach, B.S., Russ. J.
Gen. Chem., 2006, vol. 76, no. 2, p. 333.
(benzylamino)-1,3-oxazole-4-carboxamides
VIa–
VId were synthesized as described above for Ve–Vh
from enamides IIIa–IIIc and morpholine or
benzylamine.
12. Sviripa, V.M., Gakh, A.A., Brovarets, V.S., Gutov, A.V.,
and Drach, B.S., Synthesis, 2006, no. 20, p. 3462.
13. Drach, B.S., Brovarets, V.S., and Smolii, O.B., Sintezy
azotsoderzhashchikh geterotsiklicheskikh soedinenii na
osnove amidoalkiliruyushchikh agentov (Syntheses of
Nitrogen-Containing Heterocyclic Compounds on the
Basis of Amidoalkylating Agents), Kiev: Naukova
Dumka, 1992, p. 117.
ACKNOWLEDGMENTS
This study was performed under financial support
by the Ukrainian Research and Technology Center
[project no. 3017(R)].
14. Sviripa, V.N., Cand. Sci. (Chem.) Dissertation, Kiev,
2007.
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RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 4 2008