Method for the synthesis of 2-(2-furyl)acrylonitriles

Article abstract of DOI:10.1023/A:1013885107738

A new method was developed for the production of 2-(2-furl)acrylonitriles on the basis of the Schmidt reaction.

Full text of DOI:10.1023/A:1013885107738

Chemistry of Heterocyclic Compounds, Vol. 37, No. 10, 2001
METHOD FOR THE SYNTHESIS
OF 2-(2-FURYL)ACRYLONITRILES
P. A. Pavlov
A new method was developed for the production of 2-(2-furyl)acrylonitriles on the basis of the Schmidt
reaction.
Keywords: hydrazoic acid, magnesium perchlorate, 1,4-dioxanium perchlorate, furancarbaldehyde,
2-(2-furyl)acrylonitrile, perchloric acid.
The method that we developed for the single-stage synthesis of 5-substituted 2-cyanofurans from
furfurals by the Schmidt reaction, which requires a catalytic system containing 72% perchloric acid and
anhydrous magnesium perchlorate [1, 2], proved unsuitable for the synthesis of furylacrylonitriles from
furylacroleins 1a-h on account of resinification of the reaction mixture.
During study of the prospects of using perchloric acid in organic synthesis [3] it was shown that it was
capable of forming with 1,4-dioxane the stable complex 1,4-dioxanium perchlorate, which forms colorless
hygroscopic crystals with the composition 1,4-dioxane·HClO4, melting at 80°C and having high solubility in
most solvents. It was mentioned in the review [4] that the 1,4-dioxanium cation has lower electrophilicity than
the hydrated proton of perchloric acid. In view of this the catalytic system containing 1,4-dioxanium perchlorate
and anhydrous magnesium perchlorate was used as catalyst in the reaction of furylacroleins with hydrazoic acid.
This made it possible to obtain the required products 2a-h with yields of 75-95% [5, 6].
It was found, however, that the single-stage method that we developed for the production of
2-(2-furyl)acrylonitriles, which requires the use of benzene solutions of hydrazoic acid, anhydrous magnesium
perchlorate, and 1,4-dioxanium perchlorate [5, 6], can be simplified significantly by not using the difficultly
obtainable anhydrous magnesium perchlorate [7] and the 1,4-dioxanium perchlorate that requires previous
preparation. The yields of the required products 2a-h are increased by 7-10%, and the controllability of the
reaction is improved (securing uniform release of gaseous nitrogen). Benzene is replaced by chloroform
indifferent to hydrazoic acid, and the easily obtainable industrial product anhydrone (hydrated magnesium
perchlorate Mg(ClO4)2·(2-2.5)H2O), which has not only strong dehydrating capability but also the typical
characteristics of "soft" Lewis acids [3, 4, 7], is used as catalyst.
H4
H4
H3
H3
R1
R1
HN3
N2
H2O
+
+
R
R
.
Mg(ClO4)2
O
(2–2.5)H2O
O
O
CN
Ha
Ha
H
2a–h
1a–h
a R, R1 = H, H; b H, CH3; c CH3, H; d CH3, CH3; e C6H5, H; f C6H5, CH3; g 2,4,6-Cl3C6H2, H; h NO2, H
__________________________________________________________________________________________
Kuban State University, Krasnodar, Russia; e-mail: NMR_ESR@chem.kubsu.ru. Translated from
Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1315-1318, October, 2001. Original article submitted
November 26, 1999.
0009-3122/01/3710-1199$25.00©2001 Plenum Publishing Corporation
1199

TABLE 1. Spectral Characteristics of the Furylacrylonitriles 2a-h
1Н NMR spectrum
Com-
UV spectrum,
IR spectrum, cm-1
δ, ppm
HR
SSCC, Hz
J34
other
pound
λmax, nm (log ε)
SSCC, Hz
νCN
νC=C
H-3
H-4
Ha
HR'
JaR'
300 (4.32)
303 (4.43)
2220
1620, 968
6.53 (d)
6.38 (q)
7.40 (d)
7.45 (d)
7.01 (d)
5.60 (d)
3.6
3.6
17.0
J
J
H4R = 1.8
H4Ha = 1.0
2a
2b
2220
1620, 971
6.70 (d)
6.43 (dd)
6.47 (d)
2.01 (s)
2.0
J
H4R = 1.9
J
H4Ha = 1.0
312 (4.40)
305 (4.48)
2210
2200
2220
1625, 969
1620, 968
1620, 970
6.40 (d)
6.35 (d)
7.16 (d)
6.00 (dd)
6.00 (dd)
7.55 (d)
2.28 (d)
2.27 (s)
6.58-7.61 (m)
6.90 (d)
6.61 (dd)
6.98 (d)
5.45 (d)
2.01 (s)
5.68 (d)
3.6
3.6
4.0
17.0
1.8
16.5
J
J
J
H4Ha = 1.0
H4Ha = 1.0
H4Ha = 0.9
2c
2d
2e
237 (4.50)
353 (4.74)
230 (4.46)
351 (4.80)
2200
2220
2227
1610, 967
1620, 969
1620, 970
6.81 (d)
6.68 (d)
6.72 (d)
7.36 (d)
6.62 (d)
7.25 (d)
6.96-7.71 (m)
7.30 (s)
—
7.33 (d)
7.06 (s)
7.07 (d)
2.28 (s)
5.72 (d)
6.02 (d)
4.0
2.0
4.0
1.4
J
J
J
H4Ha = 1.0
H4Ha = 1.0
H4Ha = 0.9
2f
209 (4.31)
17.0
16.0
2g
2h
318 (4.41)
344 (4.34)

TABLE 2. Characteristics of the Furylacrylonitriles 2a-h
Found, %
bp, °C
(mm Hg),
mp, °C
——————
Com-
Empirical
Yield,
%
20
20
d4
nD
Calculated, %
pound formula
С
Н
N
С7Н5NO
С8Н7NO
С8Н7NO
С9Н9NO
С13Н9NO
С14Н11NO
71.29
70.58
4.14
4.20
11.73
11.76
34
95 (5)
94 (5)
112 (5)
71
—
—
84
92
92
82
95
92
93
95
2a
2b
2c
2d
2e
2f
71.15
5.48
10.70
1.1898
1.1732
1.1611
—
1.6036
1.5665
1.5710
—
72.18
5.26
10.52
72.16
72.18
5.64
5.26
10.73
10.52
73.98
6.36
9.60
73.46
6.12
9.52
80.36
80.00
4.80
4.61
7.71
7.71
81.00
5.38
6.71
138
—
—
80.38
5.26
6.69
С13Н6Сl3NO 51.69
1.90
2.00
4.67
4.66
180
—
—
2g
2h
52.00
C7H4N2O3
51.19
2.40
16.54
112
—
—
51.21
2.43
16.56
The spectral and physicochemical characteristics of compounds 2a-h are given in Tables 1 and 2.
EXPERIMENTAL
1
The H NMR spectra were recorded on a Tesla BS-467 spectrometer (60 MHz) in CCl4 at 25°C with
TMS as internal standard. The IR spectra were recorded on a UR-20 spectrophotometer in thin films
(compounds 2b-c) and in vaseline oil (compounds 2a,d-h). The electronic spectra were recorded in ethanol on a
Specord UV-Vis instrument. The solutions of hydrazoic acid in chloroform were prepared by the method in [8].
The anhydrone of pure grade was produced at the Altaikhimprom plant.
(E)-2-(2-Furyl)-1-ethenyl Cyanide (2a), (E)- 2-(2-Furyl)-1-methyl-1-ethenyl Cyanide (2b),
(E)-2-(5-Methylfur-2-yl)-1-ethenyl Cyanide (2c), (E)-2-(1-Methylfur-2-yl)-1-ethenyl Cyanide (2d),
(E)-2-(5-Phenylfur-2-yl)-1-ethenyl Cyanide (2e), (E)-1-Methyl-2-(5-phenylfur-2-yl)-1-ethenyl Cyanide
(2f), (E)-2-[5-(2,4,6-Trichlorophenyl)fur-2-yl]-1-ethenyl Cyanide (2g), and (E)-2-(5-Nitrofur-2-yl)-1-
ethenyl Cyanide (2h) (General Procedure). In a three-necked flask fitted with a magnetic stirrer and a reflux
condenser we placed the initial furylacrolein (0.1 mol), a solution of hydrazoic acid in chloroform (0.11 mol),
and anhydrone (25.0 g, 0.1 mol). Gaseous nitrogen began to be released after 5-10 min. The reaction mixture
was kept at 30°C for 40 min and then at 45-50°C for 30 min, after which the solution was boiled for 1 h with
stirring. The reaction mass was cooled to room temperature, water was added, and the organic layer was
separated. It was washed twice with water, dried with anhydrous sodium sulfate, and evaporated at reduced
pressure. The residue was distilled under vacuum, and compounds 2e-h were recrystallized from ethanol.
REFERENCES
1.
P. A. Pavlov and V. G. Kul'nevich, USSR Inventor's Certificate No. 1130566; Byull. Izobr., 47, 81
(1984).
P. A. Pavlov and V. G. Kul'nevich, Khim. Geterotsikl. Soedin., 181 (1986).
G. I. Dorofeenko and Yu. A. Zhdanov, In: Perchloric Acid and its Compounds in Organic Synthesis
[in Russian], Izd. Rostov. Un-ta, Rostov (1965), p. 148.
2.
3.
1201

4.
5.
V. Ya. Rosolovskii, In: Chemistry of Anhydrous Perchloric Acid [in Russian], Nauka, Moscow (1966),
p. 140.
P. A. Pavlov, V. G. Kul'nevich, and G. D. Krapivin, USSR Inventor's Certificate No. 1199754; Byull.
Izobr., 47, 111 (1985).
6.
7.
8.
V. G. Kul'nevich, P. A. Pavlov, and G. D. Krapivin, Khim. Geterotsikl. Soedin., 1169 (1986).
I. L. Knunyants (Ed.), Soviet Encyclopedia [in Russian], Vol. 2, Moscow (1990), p. 628.
G. V. Wolf, In: Organic Reactions [Russian translation], Vol. 3, IL, Moscow (1951), p. 293.
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