J IRAN CHEM SOC
were measured with a digital melting point apparatus
(Electrothermal) and were uncorrected. IR spectra were
determined in the region 4,000–400 cm−1 on a NEXUS 670
Diethyl 1,2‑dicyano‑3‑phenylcyclopropane‑
1,2‑dicarboxylate (3c)
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FT IR spectrometer by KBr pellets. The H and 13C NMR
Colorless crystalline solid; mp 94–95 °C. 1H NMR
(400 MHz, CDCl3) δ: 7.39 (m, 5H, Ar–H), 4.25–4.33 (m,
4H, –OCH2–CH3), 3.87 (s, 1H, cyclopropane-H), 1.30
(t, J = 7.2 Hz, 6H, –OCH2–CH3),13C NMR (100 MHz,
CDCl3) δ: 13.9, 34.2, 39.0, 64.7, 111.7, 127.8, 129.0,
129.3, 129.8, 161.2; IR (KBr, cm−1): 3,062, 3,014, 2,983,
2,937, 2,250, 1,758, 1,652, 1,503, 1,452, 1,394, 1,265,
1,202, 1,081, 1,006, 859, 751, 702, 655, 511.
spectra were recorded on Bruker 400 FT-NMR at 400 and
100 MHz, respectively (Isfahan University, Isfahan, Iran). 1H
and 13C NMR spectra were obtained on solution in DMSO-d6
and/or CDCl3 as solvent using TMS as internal standard.
The data are reported as: s = singlet, d = doublet, t = triplet,
q = quartet, m = multiplet or unresolved, bs = broad
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singlet, coupling constant(s) in Hz, integration. The H and
13C NMR spectra were opened and analyzed via MestReC
software from original spectra files. Cyanogen bromide was
aromatic (di)aldehydes, Et3N and solvents were purchased
from Merck and Aldrich without further purification.
Diethyl 1,2‑dicyano‑3‑(2‑nitrophenyl)
cyclopropane‑1,2‑dicarboxylate (3d)
Colorless crystalline solid; mp 100 °C. 1H NMR
(400 MHz, CDCl3) δ: 8.17 (d, J = 8.4 Hz, 1H, Ar–H), 7.69
(t, J = 7.6 Hz, 1H, Ar–H), 7.57 (t, J = 9.2 Hz, 2H, Ar–H),
4.44 (qd, J = 7.2, 5.6 Hz, 2H, diastereotopic –OCH2–CH3),
4.32 (s, 1H, cyclopropane-H), 4.14 (qd, J = 7.2, 5.6 Hz,
2H, diastereotopic –OCH2–CH3), 1.41 (t, J = 7.2 Hz, 3H,
–OCH2–CH3), 1.18 (t, J = 7.2 Hz, 3H, –OCH2–CH3), 13C
NMR (100 MHz, CDCl3) δ: 13.7, 14.0, 39.3, 64.9, 65.6,
110.8, 112.4, 124.0, 125.7, 130.5, 131.3, 134.2, 161.4;
IR (KBr, cm−1): 2,992, 2,931, 2,258, 1,749, 1,639, 1,579,
1,526, 1,462, 1,346, 1,300, 1,248, 1,209, 1,181, 1,098,
1,041, 985, 855, 793, 725, 661, 610.
General procedure for the synthesis of diethyl
1,2-dicyano-3-alkyl-(aryl)cyclopropane-1,2-dicarboxylate
In a 10 mL Teflon-faced screw cap tube equipped with a
magnetic stirrer and an ice bath, dissolved formaldehyde
(1.0 mmol), ethyl cyanoacetate (2.0 mmol) in 5 ml EtOH
added the appropriate base (1.33 mmol, see Table 1), and
then (1.2 mmol) cyanogen bromide was added to the solution
at 0 °C to r.t. The Teflon-faced screw cap tube prevents the
evaporation of cyanogen bromide. A cream color solid was
precipitated immediately after 5 s, after about 2 min it was
filtered off, washed with cool EtOH (3 × 3 ml), recrystallized
in minimum hot EtOH, filtered off and dried as a colorless
crystalline solid (0.236 g, 100 % yield).
Diethyl 1,2‑dicyano‑3‑(3‑nitrophenyl)
cyclopropane‑1,2‑dicarboxylate (3e)
Colorless crystalline solid; mp 133–134 °C. 1H NMR
(400 MHz, CDCl3) δ: 8.64 (s, 1H, Ar–H), 8.34 (t,
J = 7.2 Hz, 1H, Ar–H), 8.25 (s, 1H, Ar–H), 7.68 (t,
J = 8 Hz, 1H, Ar–H), 4.35 (q, J = 7.2 Hz, 4H, –OCH2–
CH3), 1.35 (t, J = 7.2 Hz, 6H, –OCH2–CH3), 13C NMR
(100 MHz, CDCl3) δ: 14.1, 63.3, 106.6, 114.6, 125.9,
127.1, 130.6, 132.9, 135.2, 148.6, 151.9, 161.5; IR (KBr,
cm−1): 3,097, 3,031, 2,989, 2,949, 2,906, 2,869, 2,225,
1,721, 1,606, 1,572, 1,528, 1,474, 1,355, 1,315, 1,267,
1,203, 1,094, 1,015, 971, 807, 763, 668, 587, 524.
Triethylammonium 1‑bromo‑1‑cyano‑2‑ethoxy‑
2‑oxoethan‑1‑ide (4a′)
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Colorless crystalline powder; mp 280–282 °C. H NMR
(400 MHz, CDCl3) δ: 8.36 (s, 1H, NH), 4.22–4.25 (m,
8H, –NCH2–CH3 and –O CH2–CH3), 1.25–1.30 (m, 12H,
–NCH2–CH3 and –OCH2–CH3), 13C NMR (100 MHz,
CDCl3) δ: 14.1, 14.4, 59.3, 61.4, 117.5, 128.8, 141.2; IR
(KBr, cm−1): 3,739, 3,425, 2,983, 2,212, 1,680, 1,506,
1,256, 1,138, 1,025, 685, 571, 444.
Diethyl 3‑(4‑nitrophenyl)‑1,2‑dicyanocyclopropane‑1,2‑
Diethyl 1,2‑dicyanocyclopropane‑1,2‑dicarboxylate (3a)
dicarboxylate (3f)
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Colorless crystalline solid; mp 78.5–79.5 °C. H NMR
Colorless crystalline solid; mp 135–136 °C. 1H NMR
(400 MHz, CDCl3) δ: 8.22 (d, J = 8.8 Hz, 2H, Ar–H), 7.52
(d, J = 8.8 Hz, 2H, Ar–H), 4.39–4.52 (m, 2H, diastereotopic
–OCH2–CH3), 4.16–4.24 (m, 2H, diastereotopic –OCH2–
CH3), 4.10 (s, 1H, cyclopropane-H), 1.41 (t, J = 7.2 Hz,
3H, –OCH2–CH3), 1.19 (t, J = 7.2 Hz, 3H, –OCH2–CH3),
13C NMR (100 MHz, CDCl3) δ: 13.8, 14.0, 31.6, 32.4, 39.3,
65.0, 65.8, 110.5, 112.3, 124.2, 129.9, 134.5, 148.3, 159.3,
(400 MHz, CDCl3) δ: 5.29 (s, 2H, cyclopropane-H),
4.36 (qd, J = 7.2, J = 2 Hz, 4H, diastereotopic –OCH2–
CH3), 1.34 (t, J = 7.2 Hz, 6H, –OCH2–CH3), 13C NMR
(100 MHz, CDCl3) δ: 14.0, 25.3, 29.7, 65.1, 112.2, 161.4;
IR (KBr, cm−1): 3,138, 3,047, 2,984, 2,940, 2,256, 1,737,
1,416, 1,375, 1,325, 1,271, 1,190, 1,160, 1,100, 995, 918,
859, 818, 859, 825, 747, 604, 557, 471, 438.
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