Functionally substituted 3-heterylpyrazoles: XI. 3-[3-Aryl(heteryl)pyrazol-4-yl]propenoic and propanoic acids

Article abstract of DOI:10.1023/A:1020905727368

3-Aryl(heteryl)-4-formylpyrazoles by condensation with malonic acid furnish 3-[3-aryl(heteryl)-pyrazol-4-yl]propenoic acids that in the presence of Raney nickel are reduced by hydrazine hydrate to 3-[3-aryl(heteryl)pyrazol-4-yl]propanoic acids. The succes

Full text of DOI:10.1023/A:1020905727368

Russian Journal of Organic Chemistry, Vol. 38, No. 8, 2002, pp. 1171 1177. From Zhurnal Organicheskoi Khimii, Vol. 38, No. 8, 2002,
pp. 1223 1229.
Original English Text Copyright
2002 by Bratenko, Chornous, Vovk.
Functionally Substituted 3-Heterylpyrazoles: XI.*
3-[3-Aryl(heteryl)pyrazol-4-yl]propenoic and Propanoic acids
M. K. Bratenko1, V. A. Chornous1, and M.V.Vovk2
1Bukovina State Medical Academy, Chernovtsy, 58000 Ukraine
2Institute of Organic Chemistry, Ukrainian National Academy of Sciences, Kiev, Ukraine
Received September 12, 2001
Abstract 3-Aryl(heteryl)-4-formylpyrazoles by condensation with malonic acid furnish 3-[3-aryl(heteryl)-
pyrazol-4-yl]propenoic acids that in the presence of Raney nickel are reduced by hydrazine hydrate to
3-[3-aryl(heteryl)pyrazol-4-yl]propanoic acids. The successive conversion of both type acids into the
corresponding acyl chlorides, esters, and amides was performed.
3-Aryl(heteryl)-4-formylpyrazoles that we used
[2] in the synthesis of the corresponding (pyrazol-4-
yl)carboxylic acids proved to be convenient substrates
for preparation of 3-(pyrazol-4-yl)propenoic acids.
We turned our attention to this type compounds for
recently the 3-heterylpropenoic acids were growing
in importance because substances with pronounced
pharmacological activity were found among them
[3 5].
Raney nickel are reduced with hydrazine hydrate to
afford in high yield 3-[3-aryl(heteryl)pyrazol-4-yl]-
propanoic acids (IIIa f). At the same time the double
bond of acid IIg with a thienyl substituent in the
pyrazole ring under the same conditions is not hydro-
genated apparently due to poisoning of the catalyst by
the sulfur-containing moiety of the substrate.
Acids IIIa f (Table 2) are colorless crystalline
compounds with the structure consistent with their
1
1
We found that 3-aryl(heteryl)-4-formylpyrazoles
Ia i with malonic acid under conditions of Knoevena-
gel reaction furnish 3-(pyrazol-4-yl)propenoic acids
IIa i in high yield (Table 1). In the IR spectra of
solid samples appear the absorption bands belonging
to bonds C=C (1635 1645), C=O (1710 1720), and
IR and H NMR spectra. Thus in their H NMR
spectra alongside the signals from substituents R at
the pyrazole ring appear broadened singlets from the
protons of carboxy groups (12.07 12.24 ppm), and
also triplets from the -methylene protons (2.78
2.90 ppm) and from -methylene protons (2.56
2.62 ppm) of the hydrocarbon chain.
1
also OH (2550 3000 cm ) thus revealing their
dimeric structure [6]. The acids of II type are trans-
isomers that is confirmed by appearance in their
1H NMR spectra of a doublet at 6.36 6.53 ppm with
a coupling constant of 17 18 Hz from the -proton
at the double bond. Therewith the doublet from the
-CH= is overlapped by the signals from the
aromatic substituents attached to the pyrazole ring
(7.11 7.93 ppm).
Taking into consideration that 3-heterylpropanoic
acids [7] and their derivatives [8, 9] also are subject
to the tests for biological activity we have studied the
ways of converting some of unsaturated acids into
their hydrogenated analogs III. It was established that
pyrazolepropenoic acids containing in position 3 of
the heterocycle aromatic substituents (IIa, c, e, f) and
also heterocyclic 3-pyridyl and 3-coumaryl substitu-
ents (IIh, i) in the presence of catalytic amounts of
I, II$(24), R = Ph (a), 4-FC6H4 (b), 4-ClC6H4 (c),
4-BrC6H4 (d), 4-CH3C6H4 (e), 4-CH3OC6H4 (f),
2-thienyl (g), 3-pyridyl (h), 3-coumaryl (i); III, R =
Ph (a), 4-ClC6H4(b), -
(c), 4-CH3OC6H4 (d),
4 CH3C6H4
*
For communication X see [1].
3-pyridyl (e), 3-coumaryl (f).
1070-4280/02/3808-1171$27.00 2002 MAIK Nauka/Interperiodica

Table 1. Yields, melting points, IR and 1H NMR spectra and elemental analyses of 3-(pyrazol-4-yl)propenoic acids IIa i
1
Compd. Yield
1H NMR spectra, , ppm
IR spectra, KBr, cm
(C=C)
78 203 205 6.45 e (1H, CH=), 7.38 7.92 m 1640
Found
H
Calcd.
H
no.
%
mp,
C
Formula
(C=O) (OH)
C
N
C
N
IIa
1715
1720
1715
1720
1720
2600
74.68 5.07 9.61 C18H14N2O2
70.51 4.20 9.18 C18H13FN202
74.47 4.86 9.65
70.12 4.25 9.09
(11H, H arom,
CH=), 9.24 s(1H,
C5H), 12.15 br.s (1H, COOH)
80 218 219 6.43 e (1H, CH=), 7.27 7.89 m
(10H, H arom, CH=), 9.24 s (1H,
C5H), 12.16 br.s (1H, COOH)
83 217 218 6.45 e (1H, CH=), 7.39 7.95 m
(10H, H arom, CH=), 9.23 s(1H,
3000
2550
IIb
IIc
IId
IIe
1645
1640
1635
1635
2980
2580
66.22 3.76 8.78 C18H13C1N2O2 66.57 4.03 8.63
58.43 3.57 7.42 C18H13BrN2O2 58.56 3.55 7.59
C5H), 12.18 br.s (1H, COOH)
3000
2600
77 223 225 6.40 e (1H, CH=), 7.29 7.74 m
(10H, H arom, CH=), 8.95 s(1H,
C5H), 12.11 br.s (1H, COOH)
2950
2500
2950
71 215 216 2.34 s (3H, CH3), 6.39 e (1H,
CH=), 7.25 7.89 m (10H, H arom,
CH=), 9.22 s (1H, C5H), 12.40
br.s (1H, COOH)
74.64 5.11 9.41 C19H16N2O2
69.88 5.27 8.70 C19Hi6N2O3
74.98 5.30 9.20
71.24 5.03 8.74
IIf
69 232 233 3.18 s (3H, CH3O), 6.46 e (1H, 1640
CH=), 7.11 e (2H, H arom), 7.39 t
(1H, H arom), 7.51 7.59 m (5H,
H arom, 2950CH=), 7.93 e (H arom),
9.20 s (1H, C5H), 12.37 br.s (1H,
COOH)
1710
2600
IIg
IIh
IIi
67 222 224 6.53 e (1H, CH=), 7.25 7.90 m (9H, 1635
H arom, CH=), 9.24 s (1H, C5H),
12.24 br.s (1H, COOH)
75 223 225 6.49 e (1H, CH=), 7.41 8.88 m (9H, 1640
H arom, CH=), 9.28 s (1H, C5H),
12.35 br.s (1H, COOH)
66 259 260 6.36 e (1H, CH=), 7.43 7.91 m (10H, 1645
H arom, CH=), 8.40 s (1H, CH=),
9.23 (1H, C5H), 12.28 br.s (1H,
COOH)
1715
1715
2550
2980
65.03 3.93 9.34 C16H12N2O2S
70.37 4.57 14.26 C17H13N3O2
70.12 4.11 7.63 C21H14N204
64.85 4.08 9.45
2590
2990
70.09
70.39
4.50 14.42
3.94 7.82
1710,
1740a
2600
2950
a
Absorption band of C=O group from coumarin ring.

FUNCTIONALLY SUBSTITUTED 3-HETERYLPYRAZOLES: XI.
1173
1
Table 2. Yields, melting points, IR and H NMR spectra, and elemental analyses of 3-(pyrazol-4-yl)propanoic acids
IIIa f
IR spectrum,
KBr, cm
Found, %
H
Calculated, %
1
Yield, mp,
1H NMR spectrum,
ppm
,
Formula
%
C
(C=O) (OH)
C
N
C
H
N
IIIa 64 141 142 2.59 t (2H, CH2), 2.87 t 1720
(2H, CH2), 7.29 7.89 m
(10H, H arom), 8.49 s
2570 74.31 5.36 9.64 C18H16N2O2
2980
73.96 5.52 9.58
(1H, C5H), 12.07 br.s
(1H, COOH)
IIIb 58 121 122 2.62 t (2H, CH2), 2.91 t 1725
(2H, CH2), 7.36 7.93 m
(9H, H arom), 8.43 s
2600 66.49 4.48 8.77 C18H15ClN2O2 66.16 4.63 8.57
2950
(1H, C5H), 12.19 br.s
(1H, COOH)
IIIc 72 103 104 2.29 s (3H, CH3), 2.60 t 1720
(2H, CH2), 2.84 t (2H,
2580 74.21 6.02 9.01 C19H18N2O2
2960
74.49 5.92 9.14
70.79 5.63 8.69
CH2), 7.21 7.75 m (9H,
H arom), 8.44 s (1H,
C5H), 12.24 br.s (1H,
COOH)
IIId 59 140 141 2.62 t (2H, CH2), 2.90 t 1720
(2H, CH2), 3.81 s (3H,
2600 80.05 5.59 8.74 C19H18N2O3
3000
CH3O), 7.04 7.87 m (9H,
H arom), 8.39 s (1H,
C5H), 12.31 br.s (1H,
COOH)
IIIe 61 194 195 2.52 t (2H, CH2), 2.94 t 1720
(2H, CH2), 7.33 8.86 m
(9H, H arom), 9.27 s
2600 69.39 5.13 14.47 C17H15N3O2
2980
69.61 5.15 14.33
69.99 4.48 7.77
(1H, C5H), 12.31 br.s
(1H, COOH)
IIIf
49 159 160 2.56 t (2H, CH2), 2.78 t 1720, 2570 69.69 4.51 7.80 C21H16N2O4
(2H, CH2), 7.32 7.87 m 1745a 2950
(9H, H arom), 8.39 s
(1H, CH=), 8.44 s (1H,
C5H), 12.13 br.s (1H,
COOH)
a
Absorption band of C=O group from coumarin ring.
Acids IIa c, f, g and IIIa d treated with thionyl
chloride provide the corresponding acyl chlorides
IVa e and Va d in high yield (Table 3). The latter
react with alcohols, phenols, and amines to furnish
esters VIa d and amides VIe j of 3-(pyrazol-4-yl)-
propenoic acids (Table 4), and also esters VIIa c and
amides VIId f of 3-(pyrazol-4-yl)propanoic acids
(Table 5).
EXPERIMENTAL
IR spectra were recorded on spectrophotometer
UR-20 from KBr pellets. 1H NMR spectra were
registered on spectrometer Varian Gemini (300 MHz)
in (CD3)2SO, internal reference TMS.
3-[3-Aryl(heteryl)pyrazol-4-yl]propenoic acids
IIa i. To a solution of 0.04 mol of aldehyde Ia i in
60 ml of anhydrous pyridine was added 8.74 g
(0.084 mol) of malonic acid, 1 ml of piperidine, and
the mixture was heated on a sand bath first to 100 C
for 0.5 h, and then 4 h at reflux till the end of carbon
By treating acyl chlorides IVa, b, d with sodium
thiocyanate in acetone substituted 3-(pyrazol-4-yl)-
propenoyl isothiocyanates VIIIa c were obtained in
high yield.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 8 2002

1174
BRATENKO et al.
Table3. Yields, melting points, and elemental analyses of 3-(pyrazol-4-yl)propenoyl and propanoyl chlorides IVa e, Va d
Compd. no.
Yield, %
mp,
C
Found Cl, %
Formula
Calculated Cl, %
IVa
IVb
IVc
IVd
IVe
Va
Vb
Vc
Vd
84
81
92
84
68
81
78
74
64
121 122
176 177
155 157
150 152
221 223
92 93
80 81
106 107
107 108
11.13
11.09
20.87
10.04
11.67
11.13
20.89
11.13
9.98
C18H13ClN2O
C18H12FClN2O
C18H12Cl2N2O
C19H15ClN2O2
C16H11ClN2OS
C18H15ClN2O
C18H14Cl2N2O
C19H17ClN2O
C19H17ClN2O2
11.48
10.85
20.66
10.46
11.26
11.41
20.54
10.91
10.40
IV, R1 = Ph (a), 4-FC6H4 (b), 4-ClC6H4 (c), 4-CH3OC6H4 (d), 2-thyonyl (e); VI, R1 = 4-CH3OC6H4, R2 = Et (a);
R2 = PhCH2: R1 = 4-ClC6H4 (b), 4-CH3OC6H4 (c); R1 = Ph, R2 = 2-CH3O-4-(CH=O)C6H3 (d); R1 =
4-ClC6H4, R3 = R4 = H (e); R1 = 4-FC6H4, R3 = H, R4 = PhCH2 (f); R1 = Ph, R3 = H, R4 = 4-CH3OC6H4 (g); R1 =
4-FC6H4, R3= H, R4 = 2,5-Cl2C6H3 (h); R1= Ph, R3 = R4 = Et (i); R1 = 4-CH3OC6H4, R3 = R4 = (CH2)2O(CH2)2 (j).
VII, R2 = Et, R1 = Ph (a), R1 = 4-ClC6H4 (b), R1 = 4-CH3OC6H4 (c); R1 = 4-ClC6H4, R3 = H, R4 = 4-FC6H4 (d);
R3 = H, R4 = 1-naphthyl, R1 = Ph (e), 4-CH3C6H4 (f).
VIII, Ar = Ph (a), 4-FC6H4 (b), 4-CH3OC6H4 (c).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 8 2002

FUNCTIONALLY SUBSTITUTED 3-HETERYLPYRAZOLES: XI.
1175
1
Table 4. Yields, melting points, IR and H NMR spectra, and elemental analyses of esters VIa d and amides VIe j of
3-(pyrazol-4-yl)propenoic acids
IR spectrum,
KBr, cm
Found, %
H
Calculated, %
1
Yield, mp,
1H NMR spectrum,
ppm
,
Formula
%
C
(C=O) (OH)
C
N
C
H
N
VIa 71 132 133 1.18 t (3H, CH3), 4.07 s 1630
(2H, CH2), 3.84 s (3H,
1720 72.71 5.69 7.83 C21H20N2O3
72.40 5.79 8.04
CH3O), 6.58 d (1H,
CH=), 7.09 7.84
m
(10H, H arom, CH=),
9.34 s (1H, C5H)
VIb 68 208 209 5.19 s (2H, CH2), 6.55 d 1635
(1H, CH=), 7.35 7.91 m
1715 72.08 4.80 6.84 C25H19ClN2O2 72.37 4.62 6.72
(15H, H arom, CH=),
9.34 s (1H, C5H)
VIc
68 140 141 3.84 s (3H, CH3O), 5.21 s 1625
(2H, CH2O), 6.55 d (1H,
CH=), 7.12 7.89 m (15H,
H arom, CH=), 9.21 s
(1H, C5H)
1715 75.62 5.69 7.03 C26H22N2O3
76.08 5.40 6.82
73.57 4.75 6.60
VId 78 164 165 3.87 s (3H, CH3O), 6.77 d 1630
(1H, CH=), 7.41 7.97 m
1720 73.23 4.85 6.63 C26H20N2O4
1690
(14H, H arom, CH=),
9.38 s (1H, C5H), 9.99 s
(1H, CH=O)
VIe
VIf
69 179 180 6.45 d (1H, CH=), 7.11 1640
7.92 m (12H, H arom,
CH=, NH2), 9.15 s (1H,
C5H)
83 213 214 4.38 s (2H, CH2), 6.51 d 1640
(1H, CH=), 7.23 7.95 m
(15H, H arom, CH=),
8.62 t (1H, NH), 8.99 s
(1H, C5H)
1700 67.10 4.09 12.73 C18H14ClN3O 66.77 4.36 12.98
1670 75.81 5.20 10.69 C25H20FN3O
1660 76.14 5.21 10.52 C25H21N3O2
75.55 5.07 10.57
75.93 5.35 10.63
VIg 76 199 200 3.73 s (3H, CH3O), 6.63 d 1630
(1H, CH=), 6.91 7.94 m
(15H, H arom, CH=),
9.00 s (1H, C5H), 10.06 s
(1H, NH)
VIh 65 220 221 6.48 d (1H, CH=), 7.14 1635
7.89 m (13H, H arom,
1670 63.99 3.36 9.44 C24H16Cl2FN3O 63.75 3.57 9.29
CH=), 8.94 s (1H, C5H),
10.09 s (1H, NH)
VIi
81 146 147 1.08 t (3H, CH3), 1.18 t 1630
(3H, CH3), 3.34 q (2H,
1675 76.30 6.87 12.32 C22H23N3O
76.49 6.71 12.16
70.93 5.95 10.79
CH2), 3.44 q (2H, CH2),
6.93 d (1H, CH=), 7.34
7.92 m (11H, H arom,
CH=), 9.19 s (1H, C5H)
VIj
74 184 185 3.44 3.70 m (8H, CH2), 1635
3.83 s (3H, CH3O), 7.11
1660 71.24 6.08 10.71 C23H23N3O3
7.91 m (14H, H arom,
CH=), 9.15 s (1H, C5H)
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1176
BRATENKO et al.
1
Table 5. Yields, melting points, IR and H NMR spectra, and elemental analyses of esters VIIa c and amides VIId f
of 3-(pyrazol-4-yl)propanoic acids
IR spectrum,
Found, %
H
Calculated, %
1
mp,
C
1H NMR spectrum, , ppm KBr, cm
Formula
(C=O)
1730
C
N
C
H
N
VIIa 66 82 84
1.14 t (3H, CH3), 2.66 t
(2H, CH2), 2.93 t (2H, CH2),
4.05 q (2H, CH2), 7.29
7.87 m (10H, H arom),
8.39 s (1H, C5H)
75.35 6.17 8.76 C20H20N2O2
74.98 6.29 8.74
VIIb 79 177 178 1.15 t (3H, CH3), 2.68 t
(2H, CH2), 2.93 t (2H, CH2),
4.04 q (2H, CH2), 7.29
1725
1735
67.95 5.27 8.06 C20H19ClN2O2 67.70 5.40 7.89
7.87 m (9H, H arom),
8.42 s (1H, C5H)
VIIc 77 49 50
1.15 t (3H, CH3), 2.67 t
(2H, CH2), 2.89 t (2H, CH2),
3.81 s (3H, CH3O), 4.06 q
(2H, CH2O), 7.03 7.86 m
(9H, H arom), 8.40 s (1H,
C5H)
71.72 6.27 8.12 C21H22N2O3
71.98 6.33 7.99
VIId 74 143 144 2.69 t (2H, CH2), 2.92 t
(2H, CH2), 7.25 7.84 m
1665
1660
1660
68.88 4.50 10.17 C24H19ClFN3O 68.65 4.56 10.01
(13H, H arom), 8.47 s (1H,
C5H), 9.84 s (1H, NH)
VIIe 70 151 152 2.89 t (2H, CH2), 3.09 t
(2H, CH2), 7.31 7.90 m
80.14 5.39 10.19 C28H23N3O
81.04 5.73 9.87 C29H25N3O
80.55 5.55 10.06
80.72 5.84 9.74
(17H, H arom), 8.52 s (1H,
C5H), 9.56 s (1H, NH)
VIIf
71 172 173 2.83 t (2H, CH2), 2.99 t
(2H, CH2), 3.80 s (3H,
CH3O), 7.11 7.84 m (16H,
H arom), 8.50 s (1H, C5H),
9.59 s (1H, NH)
dioxide evolution. The reaction mixture was cooled
and poured into a mixture of 300 g of ice and 40 m of
concn. hydrochloric acid. The precipitate was filtered
off, dried, and crystallized from glacial acetic acid.
3-[3-Aryl(heteryl)pyrazol-4-yl]propenoyl
and
3-[3-aryl(heteryl)pyrazol-4-yl]propanoyl chlorides
IVa e, Va d. To a suspension of 0.1 mol of acid
IIa c, f, g, IIIa d in 10 ml of anhydrous benzene
was added 1.75 g (0.015 mol) of thionyl chloride, and
the mixture was heated to reflux for 1 h. Then excess
thionyl chloride and benzene were distilled off, the
residue was washed with hexane, dried, and crystal-
lized from a mixture hexane benzene, 1: 1.
3-[3-Aryl(heteryl)pyrazol-4-yl]propanoic acids
IIIa f. To a suspension of acid IIa, c, e, f, h, i in
20 ml of ethanol was added 5 ml of 5 M solution of
sodium hydroxide, 2.4 g of 85% hydrazine hydrate,
and 0.06 g of Renay nickel. The reaction mixture was
heated to moderate boiling till the end of nitrogen
liberation (for around 3 4 h), then it was cooled,
diluted with 100 ml of water, and filtered. The trans-
parent filtrate was acidified with concn. hydrochloric
acid, the precipitate was dried and crystallized from
benzene.
Esters and amides of 3-[3-aryl(heteryl)pyrazol-4-
yl]propenoic and propanoic acids VIa j, VIIa f.
To a solution of 0.002 mol of acyl chloride IVa e,
Va d in 10 ml of anhydrous acetonitrile was added
0.0021 mol of an appropriate alcohol or amine,
0.2 ml of triethylamine, and the mixture was boiled
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 8 2002

FUNCTIONALLY SUBSTITUTED 3-HETERYLPYRAZOLES: XI.
1177
for 2 h. The solvent was evaporated, the residue was
washed with water, dried, and crystallized from a
mixture dioxane water, 4: 1.
CH3O), 6.53 d (1H, CH=), 7.19 d (2H arom),
7.63 m (5H arom, CH=), 7.89 d (2H arom), 9.27 s
(1H, C5H). Found, %:
N
11.50;
S
8.94.
C20H15N3O2S. Calculated, %: N 11.63; S 8.87.
3-[3-Arylpyrazol-4-yl]propenoyl isothiocyanates
VIIIa c. To a solution of 0.005 mol of acyl chloride
IVa, b, d in 30 ml of anhydrous acetone was added
0.012 mol of sodium thiocyanate, and the mixture
was stirred for 4 h at room temperature. The pre-
cipitate of sodium chloride was filtered off, the
filtrate was evaporated, the residue was purified by
crystallization.
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3-(3-Phenylpyrazol-4-yl)propenoyl
isothio-
cyanate (VIIIa). Yield 73%, mp 164 165 C. IR
1
spectrum, , cm : 1720 (C=O), 2050 (N=C=S).
1H NMR spectrum (CDCl3), , ppm: 6.43 d (1H,
CH=), 7.30 7.84 m (11H arom, CH=), 9.21 s (1H,
C5H). Found, %: N 12.92; S 9.54. C19H13N3OS.
Calculated, %: N 12.68; S 9.68.
3-[3-(4-Fluorophenyl)pyrazol-4-yl]propenoyl
isothiocyanate (VIIIb). Yield 71%, mp 176 177 C.
1
IR spectrum, , cm : 1715 (C=O), 2060 (N=C=S).
1H NMR spectrum (CDCl3), , ppm: 6.47 d (1H,
CH=), 7.38 7.93 m (10H arom, CH=), 9.23 s (1H,
C5H). Found, %: N 12.23; S 9.01. C19H12FN3OS.
Calculated, %: N 12.03; S 9.18.
3-[3-(4-Methoxyphenyl)pyrazol-4-yl]propenoyl
isothiocyanate (VIIIc). Yield 65%, mp 209 210 C.
9. Massa, S., Mai, A., Sbardella, G., Esposito, M.,
Ragno, R., Loidl, P., and Brosch, G., J. Med. Chem.,
2001, vol. 44, pp. 2069 2072.
1
IR spectrum, , cm : 1720 (C=O), 2050 (N=C=S).
1H NMR spectrum (CDCl3), , ppm: 3.43 s (3H,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 8 2002