Three ways of reactions of 5-(3,5-dimethyl-1H-pyrazol-1-yl)-2-phenyl-1,3- oxazole-4-carbonitrile and its analogs with nitrogen-containing bases

Article abstract of DOI:10.1134/S1070363208040233

Substituted 5-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3-oxazole-4-carbonitrile differently react with nitrogen bases having different numbers of labile hydrogen atoms. Treatment of the title compounds with secondary amines or morpholine results in nucleophilic replacement of the pyrazolyl substituent at C⁵, the ozaxole ring remaining unchanged. Their reactions with primary amines are accompanied by cleavage of the oxazole ring with formation of the corresponding enamino nitriles. Hydrazine hydrate acts in a similar way, but enehydrazino nitriles thus formed undergo fast cyclization to give new 4,5-diaminopyrazole derivatives. The latter can be converted into substituted pyrazolo[1,5-a]pyrimidines whose structure has been proved by X-ray analysis.

Full text of DOI:10.1134/S1070363208040233

ISSN 1070-3632, Russian Journal of General Chemistry, 2008, Vol. 78, No. 4, pp. 655–661. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © O.V. Shablykin, V.S. Brovarets, E.B. Rusanov, B.S. Drach, 2008, published in Zhurnal Obshchei Khimii, 2008, Vol. 78,
No. 4, pp. 674–679.
Three Ways of Reactions of 5-(3,5-Dimethyl-1H-pyrazol-1-yl)-
2-phenyl-1,3-oxazole-4-carbonitrile and Its Analogs
with Nitrogen-containing Bases
O. V. Shablykina, 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—Substituted 5-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3-oxazole-4-carbonitrile differently react with
nitrogen bases having different numbers of labile hydrogen atoms. Treatment of the title compounds with
secondary amines or morpholine results in nucleophilic replacement of the pyrazolyl substituent at C5, the
ozaxole ring remaining unchanged. Their reactions with primary amines are accompanied by cleavage of the
oxazole ring with formation of the corresponding enamino nitriles. Hydrazine hydrate acts in a similar way, but
enehydrazino nitriles thus formed undergo fast cyclization to give new 4,5-diaminopyrazole derivatives. The
latter can be converted into substituted pyrazolo[1,5-a]pyrimidines whose structure has been proved by X-ray
analysis.
DOI: 10.1134/S1070363208040233
We previously showed that accessible 2-acylamino-
3,3-dichloroacrylonitriles readily react with hydrazine
hydrate to give the corresponding 2-alkyl(aryl,
was conserved, and the product structure was
confirmed by independent synthesis of compounds III
by the known method, cyclocondensation of 2-
benzoylamino-3,3-dichloroacrylonitrile with the cor-
responding amine [3, 4]. The transformation II→III
attracts some interest from the theoretical viewpoint,
for it provides an additional example of relatively rare
nucleophilic substitution at C5 in oxazoles [5];
however, from the preparative viewpoint, it is less
efficient than the direct synthesis from chlorine-
containing enamido nitriles like Cl2C=C(CN)·
NHCOR1 [6].
hetaryl)-5-hydrazino-1,3-oxazole-4-carbonitriles
(I)
[1]. Systematic studies on the reactivity of these
biphilic compounds has just been started, but it is
already clear that they are capable of undergoing
unusual transformations.
The present article reports on new transformation
pathways of compounds I upon successive treatment
first with acetylacetone and then with various nitrogen-
centered bases. As we recently showed [2], in the first
step
substituted
5-(pyrazol-1-yl)-1,3-oxsazole-4-
Interestingly, strongly basic primary amines, such
as methylamine, benzylamine, and 2-phenylethyl-
amine, reacted with substituted oxazoles II along quite
different pathway. The reaction was accompanied by
cleavage of the oxazole ring, elimination of the 3,5-
dimethylpyrazolyl group did not occur, and the
products were substituted enamino nitriles IV. The
steric configuration of compounds IV was not
carbonitriles II are formed. Molecules II possess
several electrophilic centers, and we have found that
they react with nitrogen bases having different
numbers of labile hydrogen atoms along different
pathways (Scheme 1).
Oxazole II (R1 = Ph) readily reacted with
dimethylamine, piperidine, and morpholine on heating,
and the reaction involved nucleophilic replacement of
the 3,5-dimethylpyrazolyl group on C5 by the
secondary amine residue due to electron-withdrawing
effect of the cyano group on C4. Here, the oxazole ring
1
determined, but the IR and H and 13C NMR spectra
indicated predominant formation of only one
geometric isomer. Analogous oxazole ring cleavage
was observed previously in the reactions of 5-amino-4-
655

656
SHABLYKIN et al.
Scheme 1.
CN
CN
CN
Me
N
N
N
R2R3NH
R1 = Ph
(MeCO)2CH2
R1
R1
NR2R3
NHNH2
Ph
N
O
O
O
N
Ia−Ic
IIIа−IIId
IIа−IIc
Me
H2N−ΝΗ2
R4NH2
R1 = Ph
H2O
H
N
H
N
R1
C
Ph
N
CN
O
N
NH2
O
N
R4
N
N
N
N
H
H
Me
Me
Me
Me
IVа−IVc
Vа−Vc
Δ
Me
H
H2N
N
Me
O
N
O
N
N
N
R1
N
H
R1
N
(MeCO)2CH2
N
H
Δ
N
N
Me
N
Me
Me
VIа−VIc
Me
VIIа−VIIc
R1 = Me (a), Ph (b), 2-thienyl (c); R2R3N = Me2N (a), piperidino (b), morpholino (c), H2NN(Me) (d); R4 = Me (a),
PhCH2 (b), PhCH2CH2 (c).
Table 1. Yields, melting points, and elemental analyses of compounds I–VII
Found, %
Calculated, %
Comp.
no.
mp, °С (from
Yield, %
Formula
ethanol)
С
Н
N
С
H
N
85
60
75
50
60
65
55
55
230 (decomp.)
169–170
152–153
146–147
126–127
131–132
189–190
197–198
46.87
59.64
57.31
67.77
71.18
65.56
61.94
65.32
2.63
4.90
3.35
5.26
5.85
5.16
4.47
5.41
27.51
27.58
20.76
19.84
16.26
16.19
26.52
23.46
C8H6N4OS
C10H10N4O
C13H10N4OS
C12H11N3O
C15H15N3O
C14H13N3O2
C11H10N4O
C16H17N5O
46.59
59.40
57.76
67.59
71.13
65.87
61.67
65.07
2.93
4.98
3.73
5.20
5.97
5.13
4.71
5.80
27.17
27.71
20.73
19.71
16.59
16.46
26.15
23.71
Ic
IIа
IIc
IIIа
IIIb
IIIc
IIId
IVа
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 4 2008

THREE WAYS OF REACTIONS OF 5-(3,5-DIMETHYL-1H-PYRAZOL-1-YL)-...
657
Table 1. (Contd.)
Found, %
Calculated, %
Comp.
mp, °С (from
Yield, %
Formula
no.
ethanol)
С
Н
N
С
H
N
85
75
50
90
85
90
95
166–167
186–187
192–193
145–146
220–221
227–228
186–187
71.08
71.49
51.65
60.54
51.38
60.43
66.53
5.63
6.36
6.21
5.37
4.77
6.19
5.49
18.51
18.19
35.95
28.70
27.45
28.09
23.32
C22H21N5O
C23H23N5O
C10H14N6O
C15H16N6O
C13H14N6OS
C15H18N6O
C20H20N6O
71.14
71.67
51.27
60.80
51.64
60.39
66.65
5.70
6.01
6.02
5.44
4.67
6.08
5.59
18.85
18.17
35.87
28.36
27.79
28.17
23.32
IVb
IVc
VIа
VIb
VIc
VIIа
VIIb
90
210–212
59.19
5.01
22.85
C18H18N6OS
59.00
4.95
22.93
VIIc
trifluoroacetyl-1,3-oxazole derivatives with primary
and secondary amines [7]. Thus primary and secondary
amines react with 4-cyano-1,3-oxazole derivatives II,
following different pathways. Primary adducts of
oxazoles II with piperidine or morpholine contain a
specific fragment A with one labile hydrogen atom.
Elimination of that hydrogen atom as proton promotes
the transformation B → C, which is favored by
electron deficiency and appreciable nucleofugality of
the dimethylpyrazolyl group (Scheme 2).
Scheme 2.
CN
CN
Ht
CN
Ht
N
N
−
N
−
:B
−BH+
:B
−Ht−
N
+
N
O
O
O
N
H
C
А
B
CN
CN
CN
Ht
H
N
N
−
N
−
BH+
:B
−BH+
Ht
Ht
+
O
O
NH2
O N
NH
D
F
E
Ht = 3,5-dimethyl-1H-pyrazol-1-yl; B is a nitrogen base.
Adducts of oxazole II with primary amines
(structure D) possess two labile hydrogen atoms, so
that they could give rise to more diverse trans-
formations. In particular, intermediate structure E
having a C=N bond can be formed. This structure cannot
arise from structure A. Probably, an important factor
responsible for the transformations of structures A and
D is steric hindrances at the C5 atom, which affect
mutual arrangement of the dimethylpyrazolyl substi-
tuent and the oxazole ring and hence the ability of the
latter to undergo cleavage at the C–O or C–N bond.
Ring opening in substituted oxazoles II occurs in
reactions with not only primary amines but also with
hydrazine hydrates. Here, intermediate enehydrazino
nitriles V cannot be isolated as individual substances,
for they readily undergo intramolecular cyclization to
bipyrazoles VI (Scheme 1). An alternative scheme of
formation of compounds VI via addition of hydrazine
at the cyano group in II, followed by cleavage of the
oxazole ring (transformation sequence G → H → J) is
shown below.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 4 2008

658
SHABLYKIN et al.
Table 2. IR and 1H NMR spectra of compounds I–VII
Comp.
IR spectrum, ν, cm–1
1H NMR spectrum (DMSO-d6), δ, ppm
no.
2220 (C≡N), 3100–3300 (NH, NН2 аs
)
4.77 br.s (2H, NH2), 7.11 m (1Нthiophene), 7.45 m (1Нthiophene), 7.66 m (1Нthiophene), 9.18 br.s
Ic
(1H, NH)
2.26 s (3H, CH3), 2.43 s (3H, CH3) 2.55 s (3H, CH3), 6.16 s (1H, C4–Hpyrazole
2.26 s (3H, CH3), 2.55 s (3H, CH3), 6.22 s (1H, C4–Hpyrazole), 7.23 m (1Нthiophene), 7.88 m
(1Нthiophene), 7.92 m (1Нthiophene
3.29 s (3H, CH3), 5.13 br.s (2H, NH2), 7.44 m (3Нароm), 7.79 m (2Нarom
)
2260 (C≡N)
2255 (C≡N)
IIa
IIc
)
2225 (C≡N), 3250-3350 (NН2 аs
)
)
IIId
IVa
2.21 s (3H, CH3), 2.38 s (3H, CH3), 2.40 br.d (3H, CH3), 6.01 s (1H, C4–Hpyrazole), 7.19 br.q
1640 (NC=O)а, 2220 (C≡N), 3100–
3300 (NНаs)
(1H, NH), 7.52 m (3Нarom), 7.97 m (2Нarom), 9.42 br.s (1H, NH)
1640 (NC=O)а, 2220 (C≡N), 3100– 2.07 s (3H, CH3), 2.22 s (3H, CH3), 3.90 br.d (2H, CH2), 5.92 s (1H, C4–Hpyrazole), 7.30 m
3300 (NНаs) (8Нarom), 7.95 br.t (1H, NH), 8.01 m (2Нarom), 9.49 br.s (1H, NH)
1660 (NC=O)а, 2210 (C≡N), 3150– 2.23 s (3H, CH3), 2.32 s (3H, CH3), 2.63 m (2H, CH2), 2.84 m (2H, CH2), 6.05 s (1H,
IVb
IVc
3350 (NНаs)
C4–Hpyrazole), 6.97 m (2Нarom), 7.17 m (3Нarom), 7.38 br.t (1H, NH), 7.55 m (3Нarom), 8.00 m
(2Нarom), 9.44 br.s (1H, NH)
1650 (NC=O)а, 3000–3400 (NH, 1.91 s (3H, CH3), 2.21 s (3H, CH3), 2.25 s (3H, CH3), 4.82 br.s (2H, NH2), 5.90 s (1H,
NН2 аs
C4–Hpyrazole), 8.85 br.s (1H, NH), 11.53 br.s (1H, NH)
1640 (NC=O)а, 2900–3400 (NH, 2.21 s (3H, CH3), 2.38 s (3H, CH3), 5.17 br.s (2H, NH2), 7.52 m (3Нarom), 7.91 m
NН2 аs (2Нarom), 9.92 br.s (1H, NH), 11.56 br.s (1H, NH)
1650 (NC=O)а, 3000–3400 (NH, 2.20 s (3H, CH3), 2.33 s (3H, CH3), 5.07 br.s (2H, NH2), 5.97 s (1H, C4–Hpyrazole), 7.17 m
VIa
)
VIb
VIc
)
NН2 аs
)
(1Нthiophene), 7.76 m (2Нthiophene), 9.71 br.s (1H, NH), 11.63 br.s (1H, NH)
1670 (NC=O), 3250–3350 (NНаs)
1650 (NC=O), 3200–3350 (NНаs)
1650 (NC=O), 3250–3400 (NНаs)
1.94 s (3H, CH3), 2.19 s (3H, CH3), 2.32 s (3H, CH3), 2.53 s (3H, CH3), 2.66 s (3H,
CH3), 5.98 s (1H, C4–Hpyrazole), 6.91 s (1H, C5–Hpirim), 9.25 s (1H, NH)
VIIa
VIIb
VIIc
2.11 s (3H, CH3), 2.39 s (3H, CH3), 2.52 s (3H, CH3), 2.69 s (3H, CH3), 5.97 s (1H, C4–
H
pyrazole.), 6.93 s (1H, C5–Hpirim), 7.50 m (3Нarom), 7.95 m (2Нarom), 9.81 br.s (1H, NH)
2.11 s (3H, CH3), 2.33 s (1H, CH3), 2.52 s (1H, CH3), 2.69 s (3H, CH3), 6.06 s (1H, C4–
pyrazole), 7.02 s (1H, C5–Hpirim), 7.18 m (1Нthiophene), 7.83 m (1Нthiophene), 8.02 m
H
(1Нthiophene), 9.98 br.s (1H, NH)
a
Band with a shoulder.
NH
N
H
H2N
N
NHNH2
Ht
C
N
O
N
N
H2O
H2NΝΗ2
Ht
N
O
O
H
Ht
H
J
G
Ht = 3,5-dimethyl-1H-pyrazol-1-yl.
However, considerably lower electrophilicity of the
It should also be noted that no recyclization
occurred in the reaction of oxazole IIb with methyl-
hydrazine. In this case, nucleophilic replacement of the
dimethylpyrazolyl group by H2NN(Me) substituent
occurred. These data confirm the important role of
C5 atom in structure H compared to G should hinder
the recyclization H → J. Moreover, we failed to effect
analogous recyclization of compound VIII (VIII →
IX) experimentally.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 4 2008

THREE WAYS OF REACTIONS OF 5-(3,5-DIMETHYL-1H-PYRAZOL-1-YL)-...
659
O
room temperature on a Bruker Smart Apex II
diffractometer (λMoKα irradiation, graphite mono-
chromator, θmax = 26.41°, spherical segment –9 ≤ h ≤
9, –12 ≤ k ≤ 11, –12 ≤ l ≤ 15). Total of 10132
reflections were measured, 3618 of which were
independent (averaging factor R = 0.0305). Triclinic
crystals, space group P-1 (no. 2); C20H20N6O, M 360.42;
a = 7.9965(3), b = 9.6792(4), c = 12.4874(5) Å; α =
81.561(3), β = 89.576(3), γ = 70.340(3)°; V = 899.41(6) Å3;
Z = 2, dcalc = 1.331 g cm–3; μ = 0.087 mm–1; F(000) =
380. 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 [8, 9]. The
refinement was performed using 2291 reflections with
I > 2σ(I) (324 refined parameters, 7.07 reflections per
parameter) and the weight scheme ω = 1/[σ2(Fo2) +
(0.0518R)2 + 0.0565R], where R = (Fo2 + 2Fc2)/3; the
ratio of the maximal (average) shift to the error in the
last iteration cycle was 0.011 (0.001). A correction for
absorption was introduced using SADABS program
(the ratio of the minimal and maximal corrections was
O
Δ
O
NH
N
NH
NH
Ht
Ph
NH2
Ph
N
H
O
Ht
IX
VIII
intermediate enehydrazino nitriles V in the formation
of recyclization products VI. The structure of the latter
is consistent with the IR spectral data, which showed
1
the absence of cyano group in their molecules. The H
NMR spectra of VI contained proton signals assignable
to a primary amino group, acylamino residue, and
dimethylpyrazolyl fragment. In addition, the structure
of compounds VI was proved by their reactions with
acetylacetone, which lead to the formation of expected
pyrazolo[1,5-a]pyrimidine derivatives VII. The
structure of pyrazolo[1,5-a]pyrimidine VIIb (R1 = Ph)
was unambiguously determined by X-ray analysis (see
figure).
The central bicyclic system N1N2C6C7C8C9C10C11 in
molecule VIIb is almost planar: the mean-square
deviations of atoms from the corresponding plane is
0.0178 Å. The dimethyl-substituted pyrazole ring
N1N2C1C2C3 is turned through a dihedral angle of 11.3°
with respect to the bicyclic fragment. The N6C14C15O1
plane with the N1N2C6C7C8C9C10C11 plane forms a
dihedral angle of 50.7°. The N6–C4 bond [1.363(2) Å]
is shorter than the standard single C–N bond (1.45 Å),
and the sum of the bond angles at the N6 atom is 356(1)°,
indicating conjugation between the lone electron pair
on N6 and π system of the carbonyl group.
C12
C10
C9
C11
O1
N5
N4
C13
C8
C7
C14
C20
C15
C16
N6
N3
C19
C18
C6
N1
C17
N2
C1
C3
C2
Thus rigorous determination of the structure of VII
confirms the structure of products VI and the scheme
of their formation by recyclization in the course of
complex reaction of substituted oxazoles II with
hydrazine hydrate.
C5
C4
EXPERIMENTAL
Structure of the molecule of N-[2-(3,5-dimethyl-1H-pyrazol-
1-yl)-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl]benzamide
(VIIb). Principal bond lengths (Å) and bond angles (deg):
C1–N2 1.328(2), C1–C2 1.400(3), C2–C3 1.363(3), C3–N1
1.376(2), N1–N2 1.377(2), N3–N4 1.3597(19), C6–N3 1.338(2),
C6–C7 1.399(2), C7–C8 1.391(2), C8–N5 1.353(2), C8–N4
1.386(2), C9–N5 1.321(2), C9–C10 1.419(3), C10–C11 1.357(3),
C11–N4 1.368(2); N3C6C7 114.09(16), N3C6N1 118.64(15),
C7C6N1 127.23(16), C8C7N6 127.92(16), N5C8N4 121.75(16),
N5C8C7 132.72(17), O1C14N6 122.93(17), N2N1C6 117.81(14),
N3N4C11 124.22(15).
The IR spectra were recorded in KBr on a Specord
M-80 spectrometer. The 1H NMR spectra were
measured on a Varian VRX-300 instrument from
solutions in DMSO-d6 using tetramethylsilane as
internal reference.
The X-ray diffraction study on a 0.32×0.18×0.16-
mm single crystal of compound VIIb was performed at
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 4 2008

660
SHABLYKIN et al.
Tmin/Tmax = 0.852338). 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) =
0.0826, RW(F2) = 0.1148 (from all reflections, GOF
1.035) and R1(F) = 0.0451, RW(F2) = 0.0982 [from
reflections with I > 2σ(I), GOF 1.035]. The residual
electron density from the Fourier difference series after
the last iteration cycle was 0.14 and –0.23 e Å–3.
solvent was removed under reduced pressure, the
residue was treated with diethyl ether, and the
precipitate was filtered off and recrystallized from
ethanol.
N-[2-(R-Amino)-2-(3,5-dimethyl-1H-pyrazol-1-yl)-
1-cyanoethenyl]benzamides IVb and IVc (general
procedure). Compound IIb, 0.01 mol, was dissolved in
20 ml of ethanol, 0.05 mol of the corresponding amine
was added, and the mixture was heated for 3–5 h under
reflux. The solvent was removed under reduced
pressure, the residue was treated with diethyl ether,
and the precipitate was filtered off and purified by
recrystallization.
5-Hydrazino-2-methyl(phenyl)-1,3-oxazole-4-carbo-
nitriles Ia and Ib were synthesized according to the
procedure reported in [1]; 5-hydrazino-2-(2-thienyl)-
1,3-oxazole-4-carbonitrile (Ic) was synthesized in a
similar way. 5-(3,5-Dimethyl-1H-pyrazol-1-yl)-2-me-
thyl(2-thienyl)-1,3-oxazole-4-carbonitriles IIa–IIc were
prepared as described in [2].
3-Amino-4-acylamino-5-(3,5-dimethyl-1H-pyrazol-
1-yl)pyrazoles VIa–VIc (general procedure). Hydra-
zine hydrate, 0.05 mol, was added to a solution of 0.01 mol
of compound IIa–IIc in 20 ml of ethanol, the mixture
was heated for 5 h under reflux, the solvent was
removed under reduced pressure, the residue was
treated with diethyl ether, and the product was purified
by recrystallization.
5-Dimethylamino-2-phenyl-1,3-oxazole-4-carbo-
nitrile (IIIa). A solution of 0.01 mol of compound IIb
in 15 ml of ethanol was heated to the boiling point, and
gaseous dimethylamine was passed through the
solution over a period of 1 h. The mixture was then
heated for 2 h under reflux, the solvent was removed
under reduced pressure, the residue was treated with
diethyl ether, and the precipitate was filtered off and
recrystallized from ethanol. The product showed no
depression of the melting point on mixing with an
authentic sample of IIIa prepared as described in [3].
3-Acylamino-2-(3,5-dimethyl-1H-pyrazol-1-yl)-
5,7-dimethylpyrazolo[1,5-a]pyrimidines VIIa–VIIc
(general procedure). Acetylacetone, 0.1 mol, was
added to a suspension of 0.01 mol of compound IVa–
IVc in 20 ml of toluene, and the mixture was heated
for 5 h under reflux. Volatile substances were removed
under reduced pressure, the residue was treated with
diethyl ether, and the precipitate was filtered off and
recrystallized from ethanol.
5-Piperidino- and 5-Morpholino-2-phenyl-1,3-
oxazole-4-carbonitriles IIIb and IIIc (general proce-
dure). A solution of 0.01 mol of compound IIb in 15–
20 ml of ethanol was heated to the boiling point, 0.05
mol of piperidine or morpholine was added dropwise,
the mixture was heated for 3–5 h under reflux, the
solvent was removed under reduced pressure, the
residue was treated with diethyl ether, and the
precipitate was filtered off and purified by
recrystallization. The products showed no depression
of the melting point on mixing with authentic samples
of IIIb and IIIc prepared as described in [4].
ACKNOWLEDGMENTS
This study was performed under financial support
by the Ukrainian Science and Technology Center
[project no. 3017(R)].
REFERENCES
1. Pil’o, S.G., Brovarets, V.S., Vinogradova, T.K., Cherne-
ga, A.N., and Drach, B.S., Russ. J. Gen. Chem., 2001,
vol. 71, no. 2, p. 280.
2. Shablykin, O.V., Brovarets, V.S., and Drach, B.S., Russ.
J. Gen. Chem., 2007, vol. 77, no. 5, p. 936.
5-(1-Methylhydrazino)-2-phenyl-1,3-oxazole-4-car-
bonitrile (IIId) was synthesized in a similar way from
5-(3,5-dimethyl-1H-pyrazol-1-yl)-2-phenyl-1,3-oxa-zole-
4-carbonitrile (IIb) and methylhydrazine.
N-[2-(3,5-Dimethyl-1H-pyrazol-1-yl)-2-methyl-
amino-1-cyanoethenyl]benzamide (IVa). A solution
of 0.01 mol of compound IIb in 15 ml of ethanol was
heated to the boiling point, and gaseous methylamine
was passed through the solution over a period of 1 h.
The mixture was heated for 2 h under reflux, the
3. Drach, B.S. and Mis’kevich, G.N., Zh. Org. Khim., 1977,
vol. 13, no. 7, p. 1398.
4. Drach, B.S., Sviridov, E.P., Kisilenko, A.A., and Kir-
sanov, A.V., Zh. Org. Khim., 1973, vol. 9, no. 9, p. 1818.
5. Golovchenko, A.V., Brovarets, V.S., and Drach, B.S.,
Russ. J. Gen. Chem., 2004, vol. 74, no. 9, p. 1414.
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THREE WAYS OF REACTIONS OF 5-(3,5-DIMETHYL-1H-PYRAZOL-1-YL)-...
6. Drach, B.S., Brovarets, V.S., and Smolii, O.B., Sintezy
661
Fr., 1976, no. 12, p. 2053.
azotsoderzhashchikh geterotsiklicheskikh soedinenii na
osnove amidoalkiliruyushchikh agentov (Syntheses of
Nitrogen-containing Heterocyclic Compounds on the
Basis of Amidoalkylating Agents), Kiev: Naukova
Dumka, 1992, p. 92.
8. Sheldrick, G.M., SHELXS-97. Program for the Solution of
Crystal Structure, Göttingen, Germany: Univ. of
Göttingen, 1997.
9. Sheldrick, G.M., SHELXL-97. Program for the
Refinement of Crystal Structures, Göttingen, Germany:
Univ. of Göttingen, 1997.
7. Clerin, D., Meyer, B., and Fleury, J.-P., Bull. Soc. Chim.
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