Thus, the developed synthesis fundamentally improves the accessibility of 3-alkyl-2-phenyl-1-vinyl-
pyrroles not only in the laboratory, but also makes their industrial production feasible.
EXPERIMENTAL
The IR spectra were recorded on a Bruker ISF-25 spectrometer (thin layer). The 1H and 1C NMR spectra
were recorded in CDCl3 on a Bruker DPX-400 spectrometer (400 and 100 MHz respectively) with HMDS as
internal standard (δ 0.05 ppm). The purity of the obtained 1-vinylpyrroles 1a-e was monitored by GLC on an
Agilent Technologies 6890N instrument. The starting ketoximes 2a-e were obtained by the method described in
[25].
Synthesis of 3-Alkyl-2-phenyl-1-vinylpyrroles 1a-e (General Method). A mixture of DMSO (25 ml),
the alkyl phenyl ketoxime 2a-e (33 mmol), and KOH (16% relative to the mass of the oxime, calculated for
commercial 86% KOH) was heated with stirring (130°C), and acetylene was bubbled through the mixture at a
rate of ~45-50 ml/min. The reaction was monitored by GLC by taking samples after 1 hour. After 7 h, the
3-alkyl-2-phenyl-1-vinylpyrroles 1a-e and DMSO were isolated from the reaction mixture by fractional
distillation under vacuum.
3-Pentyl-2-phenyl-1-vinylpyrrole (1a). Yield 6.48 g (82%); bp 144-145°C (1-2 mm Hg) agrees with
published data [5, 23]. IR spectrum, ν, cm-1: 1318 (C–N), 1641 (СH=СH2), 3082 (=CH2). 1H NMR spectrum, δ,
ppm (J, Hz): 0.82 (3Н, t, J = 6.6, СН3); 1.23-1.25 (4Н, m, (СН2)2CH3); 1.46-1.53 (2Н, m, PyrrСН2СН2); 2.35
(2Н, t, J = 7.9, PyrrСН2); 4.48 (1Н, d, J = 7.9, НB); 5.00 (1Н, d, J = 15.8, НA); 6.19 (1Н, d, J = 3.2, Н-4); 6.65
(1Н, dd, J = 7.9, J = 15.8, НX); 7.03 (1H, d, J = 3.2, Н-5); 7.23-7.27 (2Н, m, Н-2,6 Ph); 7.30-7.34 (1Н, m, Н-4
Ph); 7.37-7.41 (2H, m, Н-3,5 Ph). 13C NMR spectrum, δ, ppm: 14.1 (СН3); 22.6, 26.0, 31.0, 31.7 ((СН2)4); 96.8
(=СH2); 110.6 (С-4); 116.2 (С-5); 124.0 (С-3); 127.4 (р-С); 128.2 (о-C); 130.3 (С-2); 131.1 (m-С); 132.0 (i-С,
N–СH=).
3-Hexyl-2-phenyl-1-vinylpyrrole (1b). Yield 5.35 g (64%); bp 157-158°C (2-3 mm Hg) agrees with
1
published data [23]. IR spectrum, ν, cm-1: 1319 (C–N), 1641 (СH=СH2), 3083 (=CH2). H NMR spectrum, δ,
ppm (J, Hz): 0.82 (3Н, t, J = 7.0, СН3); 1.17-1.26 (6Н, m, (СН2)3CH3); 1.45-1.54 (2Н, m, PyrrСН2СН2); 2.36
(2Н, t, J = 7.8, PyrrСН2); 4.48 (1Н, d, J = 8.8, НB); 5.01 (1Н, d, J = 15.7, НA); 6.19 (1Н, d, J = 2.9, Н-4); 6.65
(1Н, dd, J = 8.8, J = 15.7, НX); 7.02 (1H, d, J = 2.9, Н-5); 7.23-7.27 (2Н, m, Н-2,6 Ph); 7.30-7.34 (1Н, m, Н-4
Ph); 7.37-7.41 (2H, m, Н-3,5 Ph). 13C NMR spectrum, δ, ppm: 14.1 (СН3); 22.7, 26.1, 29.2, 31.3, 31.8 ((СН2)5);
96.7 (=СH2); 110.6 (С-4); 116.2 (С-5); 124.0 (С-3); 127.3 (р-С); 128.2 (о-С); 130.3 (С-2); 131.1 (m-С); 131.9
(i-С, N–СH=).
3-Heptyl-2-phenyl-1-vinylpyrrole (1c). Yield 5.56 g (63%), bp 160-161°С (1-2 mm Hg) agrees with
1
published data [23]. IR spectrum, ν, cm-1: 1318 (C–N), 1641 (СH=СH2), 3083 (=CH2). H NMR spectrum, δ,
ppm (J, Hz): 0.83 (3Н, t, J = 7.1, СН3); 1.17-1.25 (8Н, m, (СН2)4CH3); 1.45-1.53 (2Н, m, PyrrСН2СН2); 2.36
(2Н, t, J = 7.8, PyrrСН2); 4.50 (1Н, d, J = 8.9, НB); 5.02 (1Н, d, J = 15.8, НA); 6.18 (1Н, d, J = 2.7, Н-4); 6.66
(1Н, dd, J = 8.9, J = 15.8, НX); 7.03 (1H, d, J = 2.7, Н-5); 7.21-7.27 (2Н, m, H-2,6 Ph); 7.29-7.33 (1Н, m, H-4
Ph); 7.36-7.41 (2H, m, H-3,5 Ph). 13C NMR spectrum, δ, ppm: 14.2 (СН3); 22.7, 26.0, 29.3, 29.5, 31.3, 31.9
((СH2)6); 96.7 (=СH2); 110.5 (С-4); 116.2 (С-5); 123.9 (С-3); 127.3 (р-С); 128.2 (о-С); 130.3 (С-2); 131.0
(m-С); 131.9 (i-С, N–СH=).
3-Octyl-2-phenyl-1-vinylpyrrole (1d). Yield 5.11 g (55%), bp 166-167 °С (1-2 mm Hg) agrees with
1
published data [23]. IR spectrum, ν, cm-1: 1318 (C–N), 1641 (СH=СH2), 3083 (=CH2). H NMR spectrum, δ,
ppm (J, Hz): 0.84 (3Н, t, J = 7.0, СН3); 1.20-1.24 (10Н, m, (СН2)5CH3); 1.45-1.52 (2Н, m, PyrrСН2СН2); 2.36
(2Н, t, J = 7.8, PyrrСН2); 4.50 (1Н, d, J = 8.7, НB); 5.02 (1Н, d, J = 15.9, НA); 6.18 (1H, d, J = 2.6, Н-4); 6.66
(1Н, dd, J = 8.7, J = 15.9, НX); 7.03 (1Н, d, J = 2.6, Н-5); 7.23-7.27 (2Н, m, Н-2,6 Ph); 7.30-7.33 (1Н, m, Н-4
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