8
O.V. Petrova et al.
2 H, Ho, Ph), 7.35 (m, 1 H, Hp, Ph), 7.42 (m, 2 H, Hm, Ph), 7.84 (br s, 2 H, NH, NHPh). 13C
NMR (100.61 MHz, CDCl3): δ = 13.90 (CH3), 13.97 (CH3), 22.61, 24.01, 24.68, 27.65, 30.04
(CH2), 71.22 (C-2), 112.74 (C-7), 116.06 (CN), 125.04 (Co), 125.35 (C-7a), 127.63 (Cp), 128.08
(C-6), 129.44 (Cm), 136.47 (C-5), 137.40 (Ci), 154.64 (C-1), 158.24 (C-3). IR (KBr, ν, cm−1):
=
=
3436, 3253 (NH), 2955, 2929, 2870 (CH2, CH3), 2200 (CN), 1644 (C NH). Anal. Calcd for
C21H24N4: C, 75.87; H, 7.28; N, 16.85. Found: C, 75.58%; H, 7.39%; N, 17.03%.
4.5.3. 1-Anilino-3-imino-5,6,7,8-tetrahydro-3H-pyrrolo[1,2-a]indole-2-carbonitrile (4c)
1
Dark yellow solid; yield: 0.23 g (80%); mp. 206–208°C (n-hexane). H NMR (400.13 MHz,
CDCl3): δ = 1.67 (m, 2 H, CH2–7), 1.77 (m, 2 H, CH2-6), 2.34 (m, 2 H, CH2-8), 2.82 (m, 2 H,
CH2-5), 5.57 (s, 1 H, H-9), 7.32 (m, 2 H, Ho, Ph), 7.35 (m, 1 H, Hp, Ph), 7.42 (m, 2 H, Hm, Ph),
7.43 (br s, 1 H, NHPh), 7.81 (br s, 1 H, NH). 13C NMR (100.61 MHz, CDCl3): δ = 22.35,
=
22.99, 23.08, 23.46 (CH2), 70.89 (C-2), 111.99 (C-9), 115.92 (CN), 125.08 (Co), 125.32 (C-8a),
125.42 (C-9a), 127.67 (Cp), 129.49 (Cm), 133.80 (C-4a), 137.75 (Ci), 155.23 (C-1), 158.03 (C-3).
IR (KBr, ν, cm−1): 3440, 3233 (NH), 2933, 2922, 2847 (CH2), 2201 (CN), 1643 (C NH). Anal.
=
Calcd for C18H16N4: C, 74.98; H, 5.59; N, 19.43. Found: C, 74.70%; H, 5.60%; N, 19.70%.
4.6. Synthesis of 2-(1-anilino-2,2-dicyanoethenyl)-5-phenylpyrrole (6d)
The mixture of 2-(2,2-dicyano-1-ethylsulfanylethenyl)-5-phenylpyrrole (1d) (0.28 g, 1.0 mmol),
aniline (0.47 g, 5.0 mmol) and Et3N (0.10 g, 1.0 mmol) in EtOH (15 mL) was refluxed for 15
h. After cooling to room temperature, the reaction mixture was diluted with brine (1:3) and
the obtained precipitate was filtered off, dried and washed with cold ether. The residue was
recrystallized with benzene to give 0.26 g (84%) of compound 6d as yellow solid; mp. 244°C.
1H NMR (400.13 MHz, DMSO-d6): δ = 6.82 (dd, J = 2.4, 3.9 Hz, 1 H, H-4), 7.00 (dd, J = 2.2,
3.9 Hz, 1 H, H-3), 7.16 (m, 1 H, Hp, NHPh), 7.27 (m, 2 H, Ho, NHPh), 7.32 (m, 1 H, Hp, Ph), 7.37
(m, 2 H, Hm, NHPh), 7.41 (m, 2 H, Hm, Ph), 7.77 (m, 2 H, Ho, Ph), 10.31 (s, 1 H, NHPh), 12.15 (br
s, 1 H, NH). 13C NMR (100.61 MHz, acetone-d6): δ = 52.27 ( C(CN)2), 109.38 (C-4), 115.65
=
(CN), 117.86 (CN), 120.35 (C-3), 123.48 (Co, NHPh), 123.64 (C-2), 125.63 (Co, Ph), 125.94
(Cp, NHPh), 128.49 (Cp, Ph), 129.47 (Cm, Ph), 129.53 (Cm, NHPh), 131.74 (Ci, Ph), 139.54 (C-
5), 139.95 (Ci, NHPh), 157.14 ( C-NHPh). 15N NMR (40.55 MHz, acetone-d6): δ = −263.9
=
(NHPh), − 229.5 (NH). IR (KBr, ν, cm−1): 3291, 3228 (NH), 2207, 2200 (CN). Anal. Calcd for
C20H14N4: C, 77.40; H, 4.55; N, 18.05. Found: C, 77.14%; H, 4.51%; N, 18.35%.
4.7. General procedure for the synthesis of
2-(1-anilino-2,2-dicyanoethylethenyl)-5-arylpyrroles (6e,f)
The mixture of 2-(2,2,-dicyano-1-ethylsulfanylethenyl)-5-arylpyrroles 1e,f (0.73 mmol), aniline
(0.34 g, 3.65 mmol) and Et3N (0.074 g, 0.73 mmol) in EtOH (50 mL) was refluxed for 15
h. After cooling to room temperature, the reaction mixture was diluted with brine (1:4) and
extracted with CH2Cl2 (5 × 20 mL). The extracts was washed with water (3 × 20 mL) and dried
over K2CO3. The residue after removing the solvent was fractionated by column chromatography
(Al2O3, CH2Cl2) or recrystallized from benzene to give compounds 6e,f correspondingly.
4.7.1. 2-(1-Anilino-2,2-dicyanoethylethenyl)-5-(4-methylphenyl)pyrrole (6e)
Yellow solid; yield 0.062 g (26%); mp. 258–260°C (CCl4). 1H NMR (400.13 MHz, DMSO-d6):
δ = 2.32 (s, 3 H, CH3Ph), 6.77 (d, J = 3.9 Hz, 1 H, H-4), 7.00 (d, J = 3.9 Hz, 1 H, H-3), 7.20
(m, 1 H, Hp, NHPh), 7.24 (m, 2 H, Ho, NHPh), 7.25 (m, 2 H, Hm, Ph), 7.37 (m, 2 H, Hm, NHPh),