Three-component synthesis of functionalized 1-Azabuta-1,3-dienes from alkyl isocyanides, activated acetylenes, and pyridin-2(1H)-one or isoquinolin-1(2H)-one

Article abstract of DOI:10.1080/00397911003611802

The 1:1 reactive intermediates generated by the addition of alkyl isocyanides to dialkyl acetylenedicarboxylates were trapped by pyridin-2(1H)-one and isoquinolin-1(2H)-one to yield highly functionalized 1-azabuta-1,3-dienes and, in some cases, minor amou

Full text of DOI:10.1080/00397911003611802

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Three-Component Synthesis of
Functionalized 1-Azabuta-1,3-dienes
from Alkyl Isocyanides, Activated
Acetylenes, and Pyridin-2(1H)-one or
Isoquinolin-1(2H)-one
Bita Mohtat a , Hoorieh Djahaniani b , Roshanak Khorrami a , Samira
Mashayekhi a & Issa Yavari c
a Chemistry Department, Islamic Azad University, Karaj Branch, Iran
b Chemistry Department, Tehran Shargh Branch, Islamic Azad
University, Tehran, Iran
c Chemistry Department, Islamic Azad University, Science and
Research Branch, Tehran, Iran
Published online: 25 Feb 2011.
To cite this article: Bita Mohtat , Hoorieh Djahaniani , Roshanak Khorrami , Samira Mashayekhi
& Issa Yavari (2011): Three-Component Synthesis of Functionalized 1-Azabuta-1,3-dienes from
Alkyl Isocyanides, Activated Acetylenes, and Pyridin-2(1H)-one or Isoquinolin-1(2H)-one, Synthetic
Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry,
41:6, 784-791
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Synthetic Communications1, 41: 784–791, 2011
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397911003611802
THREE-COMPONENT SYNTHESIS OF
FUNCTIONALIZED 1-AZABUTA-1,3-DIENES FROM
ALKYL ISOCYANIDES, ACTIVATED ACETYLENES, AND
PYRIDIN-2(1H)-ONE OR ISOQUINOLIN-1(2H)-ONE
Bita Mohtat,1 Hoorieh Djahaniani,2 Roshanak Khorrami,1
Samira Mashayekhi,1 and Issa Yavari3
1Chemistry Department, Islamic Azad University, Karaj Branch, Iran
2Chemistry Department, Tehran Shargh Branch, Islamic Azad University,
Tehran, Iran
3Chemistry Department, Islamic Azad University, Science and Research
Branch, Tehran, Iran
GRAPHICAL ABSTRACT
Abstract The 1:1 reactive intermediates generated by the addition of alkyl isocyanides to
dialkyl acetylenedicarboxylates were trapped by pyridin-2(1H)-one and isoquinolin-1(2-
H)-one to yield highly functionalized 1-azabuta-1,3-dienes and, in some cases, minor
amounts of ketenimines.
Keywords Acetylenic esters; alkyl isocyanides; 1-azadienes; ketenimines; multicompo-
nent reaction; NH acids
INTRODUCTION
Isocyanides are compounds with an extraordinary functional group; its
unusual valence structure and reactivity have been discussed for more than 150
years. The fascinating chemistry that stems from the addition of isocyanides to acti-
vated acetylenic compounds has evoked considerable interest.[1] Usually, the
addition of isocyanides devoid of an acidic hydrogen atom leads to a 1:1 zwitterionic
intermediate that can undergo further transformations, culminating in a stabilized
product.[2–4] Of importance in this area are the isocyanide-based multicomponent
reactions (MCRs) such as the versatile Ugi and Passerini reactions.[5–8] The reactions
Received November 21, 2009.
Address correspondence to Issa Yavari, Chemistry Department, Tarbiat Modares University, P.O.
Box 14115-175, Tehran, Iran. E-mail: yavarisa@modares.ac.ir
784

SYNTHESIS OF 1-AZABUTA-1,3-DIENES
785
of 1-azadienes with various chiral dienophiles, which lead to substituted pyridines,
have been reported.[9] Recently, we described a convenient method for preparation
of 1-azadienes, by three-component reaction of 3-chloropentan-2,4-dione, dialkyl
acetylenedicarboxylates, and 2,6-dimethylphenyl isocyanide.[10]
RESULTS AND DISCUSSION
In continuation of our interest in the application of isocyanides in MCRs,[11–14]
we report herein an efficient synthesis of 1-azadienes 4 from alkyl isocyanides 1, dia-
lkyl acetylenedicarboxylates 2, and strong NH acids, such as pyridin-2(1H)-one or
isoquinolin-1(2H)-one. In some cases, minor amounts (13–25%) of ketenimines 5
are obtained (Scheme 1).
The reaction proceeded spontaneously in CH2Cl2 and was completed within a
few hours. The 1H and 13C NMR spectra of the crude products clearly indicated the
formation of 4 and 5. The structures of compounds 4a–j were deduced from their
1
elemental analyses and their infrared (IR), H NMR, and 13C NMR spectra. The
mass spectra of these compounds displayed molecular ion peaks at appropriate
m=z values, and the 1H NMR spectrum of 4a exhibited four sharp lines for tert-butyl
(d ¼ 1.29 ppm), methoxy (d ¼ 3.66 and 3.90 ppm), and vinyl (d ¼ 6.77 ppm) protons.
The pyridinol moiety appeared at d ¼ 6.19–8.00 ppm. The 13C NMR spectrum of
4a showed 14 distinct resonances in agreement with the dimethyl 2-{(tert-
butylimino)[2-oxopyridin-1(2H)-yl]methyl}but-2-enedioate assignment. Structural
partial assignments of these resonances are given in the Experimental section. The
1H NMR spectra of 4b–f are similar to that of 4a, except for the signals of the cyclo-
hexyl, ester, and heterocyclic moieties. Each pair of compounds 4a–d and 5a–d was
Scheme 1.

786
B. MOHTAT ET AL.
Scheme 2.
analyzed as a mixture. The structural assignments of 5a–d made on the basis of their
NMR spectra were supported by their IR spectra. Of special interest is the strong
ketenimine absorption band at about n ¼ 2060 cmꢀ1
.
On the basis of the well-established chemistry of isocyanides,[14] it is reason-
able to assume that 4 and 5 result from initial addition of the alkyl isocyanide to
the acetylenic ester and subsequent protonation of the 1:1 adduct 6 by the
NH-acidic compound 3. Then, the positively charged ion can be attacked by the
nitrogen atom of the anion of the NH-acidic compound at two positions. Direct
addition leads to 1-azadienes 4 and conjugate addition produces ketenimines 5
(Scheme 2).
In conclusion, we have found a simple and efficient method for the preparation
of highly functionalized 1-azadienes. The present method carries the advantages that
not only is the reaction performed under neutral conditions, but also the starting
materials and reagents can be mixed without any activation or modification.
EXPERIMENTAL
Melting points were measured on an Electrothermal 9100 apparatus. Elemental
analyses for C, H, and N were performed using a Heraeus CHNO-Rapid analyzer.
1
IR spectra were measured on a Shimadzu IR-460 spectrometer. H and 13C NMR
spectra were measured with a Bruker DRX-500 Avance instrument with CDCl3
(300.1 and 75.5 MHz, respectively). Mass spectra were recorded on a Finnigan-Matt
8430 mass spectrometer operating at an ionization potential of 70 eV. Alkyl isocya-
nides, dialkyl acetylenedicaboxylates, and compounds 3a and 3b (Fluka) were used
without further purification.
General Procedure for the Preparation of Compounds 4: Dimethyl
2-{(t-Butylimino)[2-oxopyridin-1(2H)-yl]methyl}but-2-enedioate (4a)
To a stirred solution of pyridin-2-ol (0.38 ml, 2 mmol) and dimethyl acetylene-
dicarboxylate (0.28 ml, 2 mmol) in 10 mL of CH2Cl2, tert-butyl isocyanide (0.26 g,
2 mmol) was added dropwise at ꢀ10 ꢁC over 10 min. The reaction mixture was then
allowed to warm to room temperature and stand for 24 h. The solvent was removed
under reduced pressure, and the residual solid was recrystallized from diethyl ether.
Oily products were purified by preparative thin-layer chromatography (TLC) on
silica gel (Merck silica gel DC-Fertigplatten 60=Kieselgur F254) 20 ꢂ 20-cm plates
using n-hexane–AcOEt (2:1) as eluent.

SYNTHESIS OF 1-AZABUTA-1,3-DIENES
787
Data
Dimethyl 2-{(t-butylimino)[2-oxopyridin-1(2H)-yl]methyl}but-2-enedio-
ate (4a) and dimethyl 2-{(t-butylimino-methylene)-3-[2-oxopyridin-1(2H)-
yl]}succinate (5a). Yellow oil. IR (KBr) (tmax=cmꢀ1): 2062 (C C N), 1740
=
=
=
=
=
=
=
(C O), 1725 (C O), 1677 (C O), 1663 (C O), 1593 (C N). MS (EI, 70 eV): m=z
(%): 320 (Mþ, 15), 263 (14), 226 (39), 143 (64), 94 (70), 57 (100), 41 (87). Anal. calcd.
for C16H20N2O5 (320.35): C, 59.99; H, 6.29; N, 8.74. Found: C, 59.90; H, 6.33; N,
1
8.71. NMR data for 4a (75%): H NMR: d ¼ 1.29 (9 H, s, Me3C), 3.66 (3 H, s,
3
MeO), 3.90 (3 H, s, MeO), 6.20 (1 H, t, J 7.3 Hz, CH), 6.37 (1 H, d, J 9.2 Hz,
3
3
CH), 6.77 (1 H, s, CH), 7.29 (1 H, t, J 9.0 Hz, CH), 8.00 (1 H, d, J 7.1 Hz, CH).
3
13
=
C NMR: d ¼ 30.2 (Me3C), 52.3 (MeO), 52.1 (MeO), 57.5 (CꢀN), 105.8 (CH ),
=
=
=
=
=
121.5 (CH ), 124.7 (CH ), 136.0 (CH ), 140.6 (CH ), 142.6 (C ), 142.8 (CꢀN),
162.3 (C O), 163.9 (C O), 164.7 (C O). NMR data for 5a (13%): 1H NMR:
=
=
=
d ¼ 1.19 (9 H, s, Me3C), 3.68 (3 H, s, MeO), 3.86 (3 H, s, MeO), 5.73 (1 H, s,
3
3
3
CH), 6.26 (1 H, t, J 6.8 Hz, CH), 6.58 (1 H, d, J 8.9 Hz, CH), 7.42 (1 H, t, J
8.8 Hz, CH), 7.60 (1 H, d, 3J 6.8 Hz, CH). 13C NMR: d ¼ 29.6 (Me3C), 52.3
=
=
=
(MeO), 52.6 (MeO), 57.5 (CꢀN), 59.9 (CH), 61.3 (C C N), 105.4 (CH ), 122.0
=
=
=
=
=
=
(CH ), 135.3 (CH ), 140.8 (CH ), 161.5 (C O), 162.39 (C O), 164.70 (C O),
=
168.7 (C C N).
=
Di-t-butyl 2-{(t-butylimino)[2-oxopyridin-1(2H)-yl]methyl}but-2-enedio-
ate (4b) and di-t-butyl 2-{(t-butylimino-methylene)-3-[2-oxopyridin-1(2H)-
yl]}succinate (5b). Yellow oil. IR (KBr) (tmax=cmꢀ1): 2071 (C C N), 1748
=
=
=
=
=
=
=
(C O), 1714 (C O), 1661 (C O). 1656 (C O), 1596 (C N). MS (EI, 70 eV): m=z
(%): 404 (Mþ, 13), 310 (14), 236 (33), 192 (57), 142 (34), 95 (56), 57 (100), 41 (87).
Anal. calcd. for C22H32N2O5 (404.51): C, 65.32; H, 7.97; N, 6.93. Found: C,
65.35; H, 7.93; N, 6.96. NMR data for 4b (68%): 1H NMR: d ¼ 1.34 (9 H, s,
3
Me3C), 1.36 (9 H, s, Me3C), 1.58 (9 H, s, Me3C), 6.16 (1 H, t, J 7.4 Hz, CH),
3
6.41 (1 H, d, J 9.2 Hz, CH), 6.67 (1 H, s, CH), 7.28 (1 H, t, J 9.0 Hz, CH), 8.05
3
(1 H, d, J 7.1 Hz, CH). 13C NMR: d ¼ 28.2 (Me3C), 28.4 (Me3C), 30.6 (Me3C),
3
=
=
=
57.7 (CꢀN), 82.0 (CꢀO), 83.0 (CꢀO), 105.5 (CH ), 122.2 (CH ), 127.2 (CH ),
=
136.8 (CH ), 140.5 (CH ), 143.1 (C ), 143.8 (C N), 162.6 (C O), 162.8 (C O),
=
=
=
=
=
1
=
164.1 (C O). NMR data for 5b (25%): H NMR: d ¼ 1.27 (9 H, s, Me3C), 1.45 (9
3
H, s, Me3C), 1.56 (9 H, s, Me3C), 5.81 (1 H, s, CH), 6.15 (1 H, t, J 6.7 Hz, CH),
3
3
3
6.53 (1 H, d, J 9.0 Hz, CH), 7.32 (1 H, t, J 8.8 Hz, CH), 7.63 (1 H, d, J 6.8 Hz,
CH). 13C NMR: d ¼ 28.2 (Me3C), 28.7 (Me3C), 30.5 (Me3C), 57.7 (CꢀN), 60.0
=
=
=
=
(CH), 62.5 (C C N), 80.9 (CꢀO), 82.9 (CꢀO), 105.7 (CH ), 120.5 (CH ), 138.0
=
(CH ), 140.0 (CH ), 164.8 (C O), 165.6 (C O), 166.6 (C O), 168.1 (C C N).
=
=
=
=
= =
Dimethyl 2-{(t-butylimino)[1-oxoisoquinolin-1(2H)-yl]methyl}but-2-
enedioate (4c) and dimethyl 2-{(t-butylimino-methylene)-3-[2-oxoisoquino-
lin-1(2H)-yl]}succinate (5c). Yellow oil. IR (KBr) (tmax=cmꢀ1): 2068 (C C N),
=
=
=
=
=
=
=
1745 (C O), 1724 (C O), 1655 (C O), 1654 (C O), 1624 (C N). MS (EI, 70 eV):
m=z (%): 370 (Mþ, 4), 313 (31), 226 (29), 143 (85), 57 (100), 41 (34). Anal. calcd.
for C20H22N2O5 (370.41): C, 64.85; H, 5.99; N, 7.56. Found: C, 64.89; H, 5.94; N,
1
7.60. NMR data for 4c (77%): H NMR: d ¼ 1.33 (9 H, s, Me3C), 3.65 (3 H, s,
3
MeO), 3.96 (3 H, s, MeO), 6.54 (1 H, d, J 7.8, Hz CH), 6.84 (1 H, s, CH), 7.42

788
B. MOHTAT ET AL.
(1 H, t, 3J 8.1 Hz, CH), 7.48 (1 H, d, 3J 7.8 Hz, CH), 7.62 (1 H, t, 3J 7.8 Hz, CH), 7.97
3
3
(1 H, d, J 7.9 Hz, CH), 8.32 (1 H, d, J 8.2 Hz, CH). 13C NMR: d ¼ 30.8 (Me3C),
=
=
=
52.6 (MeO), 53.3 (MeO), 57.6 (CꢀN), 106.8 (CH ), 125.1 (CH ), 126.2 (CH ),
=
126.8 (C ), 127.1 (CH ), 128.6 (CH ), 130.3 (CH ), 133.3 (CH ), 137.6 (C ),
=
=
=
=
=
=
143.5 (C ), 152.6 (C N), 162.5 (C O), 164.6 (C O), 165.1 (C O). NMR data
=
=
=
=
1
for 5c (15%): H NMR: d ¼ 1.48 (9 H, s, Me3C), 3.70 (3 H, s, MeO), 3.76 (3 H, s,
3
MeO), 5.85 (1 H, s, CH), 6.52 (1 H, d, J 7.5 Hz, CH), 7.32 (1 H, d, J 7.5 Hz,
3
3
3
3
CH), 7.44 (1 H, t, J 7.8 Hz, CH), 7.52 (1 H, d, J 7.8 Hz, CH), 7.63 (1 H, t, J
7.7 Hz, CH), 8.38 (1 H, d, 3J 7.9 Hz, CH). 13C NMR: d ¼ 30.5 (CMe3), 52.2
=
=
(OMe), 53.3 (OMe), 59.9 (CN), 61.1 (CH), 62.9 (C C N), 106.3 (CH ), 126.3
=
=
(CH ), 126.8 (CH ), 128.2 (CH ), 131.7 (CH ), 132.7 (CH ), 133.3 (C ), 137.6
=
=
=
=
=
=
(C ), 162.2 (C O), 165.9 (C O), 168.8 (C O), 170.6 (C C N).
=
=
=
= =
Di-t-butyl 2-{(t-butylimino)[1-oxoisoquinolin-1(2H)-yl]methyl}but-2-
enedioate (4d) and di-t-butyl 2-{(t-butylimino-methylene)-3-[2-oxoisoquino-
lin-1(2H)-yl]}succinate (5d). Yellow oil. IR (KBr) (tmax=cmꢀ1): 2061 (C C N),
=
=
=
=
=
=
=
1742 (C O), 1709 (C O), 1658 (C O), 1654 (C O), 1626 (C N). MS (EI, 70 eV):
m=z (%): 454 (Mþ, 2), 310 (24), 254 (23), 198 (35), 145 (82), 57 (100), 41 (30). Anal.
calcd. for C26H34N2O5 (454.57): C, 68.70; H, 7.54; N, 6.16. Found: C, 68.73; H, 7.50;
1
N, 6.12. NMR data for 4d (63%): H NMR: d ¼ 1.32 (9 H, s, Me3C), 1.35 (9 H, s,
3
Me3C), 1.59 (9 H, s, Me3C), 6.50 (1 H, d, J 7.8 Hz, CH), 6.71 (1 H, s, CH), 7.41
3
(1 H, t, J 7.9 Hz, CH), 7.47 (1 H, d, J 7.6 Hz, CH), 7.60 (1 H, t, J 7.8 Hz, CH),
3
3
8.04 (1 H, d, J 7.9 Hz, CH), 8.35 (1 H, d, J 8.1 Hz, CH). 13C NMR: d ¼ 28.2
3
3
(Me3C), 28.4 (Me3C), 30.9 (Me3C), 57.2 (C-N), 81.9 (CꢀO), 82.9 (CꢀO), 106.3
=
(CH ), 126.0 (CH ), 126.9 (CH ), 127.0 (CH ), 127.1 (C ), 128.8 (CH ), 130.3
=
=
=
=
=
=
(CH ), 133.0 (CH ), 137.6 (C ), 143.5 (C ), 143.9 (C N), 162.3 (C O), 163.2
=
=
=
=
=
1
=
=
(C O), 164.2 (C O). NMR data for 5d (24%): H NMR: d ¼ 1.23 (9 H, s, Me3C),
3
1.43 (9 H, s, Me3C), 1.56 (9 H, s, Me3C), 5.66 (1 H, s, CH), 6.48 (1 H, d, J
3
7.5 Hz, CH), 7.43 (1 H, d, J 7.5 Hz, CH), 7.45 (1 H, t, J 7.8 Hz, CH), 7.50 (1 H,
3
d, J 7.8 Hz, CH), 7.62 (1 H, t, J 7.8 Hz, CH), 8.41 (1 H, d, 3J 7.9 Hz, CH).
3
3
13C-NMR: d ¼ 28.3 (Me3C), 28.7 (Me3C), 30.6 (Me3C), 60.1 (CꢀN), 62.5 (CH),
=
=
=
=
64.2 (C C N), 81.0 (CꢀO), 82.8 (CꢀO), 105.8 (CH ), 126.1 (CH ), 126.3
=
=
(CH ), 126.7 (CH ), 128.4 (CH ), 131.5 (CH ), 132.5 (C ), 137.6 (C ), 162.1
=
=
=
=
=
(C O), 167.5 (C O), 167.6 (C O), 169.0 (C C N).
=
=
= =
Dimethyl
2-{(cyclohexylimino)[2-oxopyridin-1(2H)-yl]methyl}but-2-
enedioate (4e). Yellow powder; yield: 0.54 g (78%), mp 164–168 ꢁC. IR (KBr)
(tmax=cmꢀ1): 1725 (C O), 1664 (C O), 1595 (C N). MS (EI, 70 eV): m=z (%):
346 (Mþ, 11), 252 (100), 170 (92), 138 (20), 83 (48), 55 (38), 41 (26). Anal. calcd.
for C18H22N2O5 (346.38): C, 62.42; H, 6.40; N, 8.09. Found: C, 62.39; H, 6.44;
N, 8.01. H NMR: d ¼ 1.26–1.88 (10 H, m, 5 CH2), 3.27 (1 H, m, HC-N), 3.65
=
=
=
3
3
(3 H, s, MeO), 3.89 (3 H, s, MeO), 6.24 (1 H, t, J 7.1, CH), 6.40 (1 H, d, J
3
3
9.2 Hz, CH), 6.79 (1 H, s, CH), 7.32 (1 H, t, J 9.2 Hz, CH), 8.01 (1 H, d, J
7.1 Hz, CH). 13C NMR: d ¼ 23.9 (CH2), 24.0 (CH2), 25.5 (CH2), 32.8 (2 CH2),
=
=
52.2 (MeO), 52.9 (MeO), 60.4 (CꢀN), 106.0 (CH ), 121.3 (CH ), 124.7
=
(CH ), 135.7 (CH ), 140.7 (CH ), 140.8 (C ), 147.5 (C N), 162.2 (C O),
=
=
=
=
=
=
=
163.3 C O), 164.4 (C O).

SYNTHESIS OF 1-AZABUTA-1,3-DIENES
789
Diethyl
2-{(cyclohexylimino)[2-oxopyridin-1(2H)-yl]methyl}but-2-
enedioate (4f). Yellow powder; yield: 0.56 g (75%), mp 167–171 ꢁC. IR (KBr) (t
max=cmꢀ1): 1741 (C O), 1660 (C O), 1596 (C N). MS (EI, 70 eV): m=z (%): 374
(Mþ, 9), 277 (100), 171 (86), 97 (22), 83 (50), 77 (35), 29 (30). Anal. calcd. for
C20H26N2O5 (374.43): C, 64.15; H, 7.00; N, 7.48. Found: C, 64.19; H, 7.04; N,
=
=
=
7.42.1H NMR: d ¼ 1.20 (3 H, t, J 7.1 Hz, Me-CH2), 1.28–1.88 (10 H, m, 5 CH2),
3
3
3
1.35 (3 H, t, J 7.1 Hz, Me-CH2), 3.32 (1 H, m, H-CN), 4.10 (2 H, q, J 7.1 Hz,
CH2O), 4.39 (2 H, m, CH2O), 6.24 (1 H, t, 3J 7.2 Hz, CH), 6.42 (1 H, d, 3J
3
3
9.1 Hz, CH), 6.80 (1 H, s, CH), 7.32 (1 H, t, J 9.2 Hz, CH), 8.05 (1 H, d, J
7.3 Hz, CH). 13C NMR: d ¼ 14.0 (Me-CH2), 14.1 (Me-CH2), 23.9 (CH2), 24.1
(CH2), 25.6 (CH2), 31.2 (2 CH2), 60.3 (CꢀN), 61.2 (CH2O), 62.2 (CH2O), 106.0
=
=
=
=
=
=
(CH ), 121.4 (CH ), 125.3 (CH ), 135.8 (CH ), 140.7 (CH ), 140.8 (C ), 148.2
=
=
=
=
(C N), 162.2 (C O), 162.9 (C O), 164.1 (C O).
Di-t-butyl
2-{(cyclohexylimino)[2-oxopyridin-1(2H)-yl]methyl}but-
2-enedioate (4g). Yellow powder; yield: 0.65 g (76%), mp 170–174 ꢁC. IR (KBr)
(tmax=cmꢀ1): 1716 (C O), 1665 (C O), 1628 (C N). MS (EI, 70 eV): m=z (%):
430 (Mþ, 7), 397 (100), 227 (83), 107 (25), 83 (45), 42 (20). Anal. calcd. for
C24H34N2O5 (430.54): C, 66.95; H, 7.96; N, 6.51. Found: C, 66.90; H, 7.95; N,
=
=
=
1
6.58. H NMR: d ¼ 1.26–1.78 (10 H, m, 5CH2), 1.34 (9 H, s, Me3C), 1.55 (9 H, s,
3
Me3C), 3.30 (1 H, m, N-CH), 6.19 (1 H, t, J 7.3 Hz, CH), 6.42 (1 H, d, J 9.5 Hz,
3
3
3
CH), 6.70 (1 H, s, CH), 7.29 (1 H, t, J 9.2 Hz, CH), 8.50 (1 H, d, J 7.2 Hz, CH).
13C NMR: d ¼ 24.0 (CH2), 24.2 (CH2), 25.6 (CH2), 27.8 (Me3C), 27.9 (Me3C),
=
=
32.7 (2CH2), 60.2 (CꢀN), 81.7 (CꢀO), 82.6 (CꢀO), 105.5 (CH ), 121.6 (CH ),
=
=
=
=
=
=
127.2 (CH ), 136.1 (CH ), 140.4 (CH ), 140.6 (C ), 148.5 (C N), 161.9 (C O),
=
162.1 (C O), 163.5 (C O).
=
Dimethyl 2-{(cyclohexylimino)[1-oxoisoquinolin-1(2H)-yl]methyl}but-
2-enedioate (4h). Yellow powder; yield: 0.69 g (88%), mp 173–177 ꢁC. IR (KBr)
(tmax=cmꢀ1): 1726 (C O), 1657 (C O), 1626 (C N). MS (EI, 70 eV): m=z (%):
396 (Mþ, 10), 280 (37), 227 (100), 170 (55), 83 (45), 55 (38). Anal. calcd. for
C22H24N2O5 (396.44): C, 66.65; H, 6.10; N, 7.07. Found: C, 66.69; H, 6.13; N,
=
=
=
1
7.02. H NMR: d ¼ 1.27–1.85 (10 H, m, 5 CH2), 3.32 (1 H, m, HC-N), 3.65 (3 H,
3
s, MeO), 3.96 (3 H, s, MeO), 6.59 (1 H, d, J 7.8 Hz, CH), 6.87 (1 H, s, CH), 7.44
3
(1 H, t, J 7.9 Hz, CH), 7.51 (1 H, d, J 7.8 Hz, CH), 7.64 (1 H, t, J 7.8 Hz, CH),
3
3
3
3
7.96 (1 H, d, J 7.8 Hz, CH), 8.33 (1 H, d, J 7.8 Hz, CH). 13C NMR: d ¼ 24.4
(CH2), 24.6 (CH2), 26.1 (CH2), 33.5 (2 CH2), 52.6 (MeO), 53.5 (MeO), 60.6
=
=
=
=
=
(CꢀN), 107.2 (CH ), 125.2 (CH ), 126.4 (CH ), 126.5 (C ), 127.3 (CH ), 128.6
=
(CH ), 129.9 (CH ), 133.4 (CH ), 137.6 (C ), 141.5 (C ), 147.9 (C N), 162.5
=
=
=
=
=
=
=
(C O), 164.1 (C O), 164.9 (C O).
=
Diethyl
2-{(cyclohexylimino)[1-oxoisoquinolin-1(2H)-yl]methyl}but-
2-enedioate (4i). Yellow powder; yield: 0.69 g (82%), mp 178–180 ꢁC. IR (KBr)
(tmax=cmꢀ1): 1728 (C O), 1665 (C O), 16245 (C N). MS (EI, 70 eV): m=z (%):
424 (Mþ, 7), 280 (31), 253 (56), 227 (100), 171 (48), 83 (41), 29 (35). Anal. calcd.
for C24H28N2O5 (424.49): C, 67.91; H, 6.65; N, 6.60. Found: C, 67.88; H, 6.68; N,
=
=
=
6.63.1H NMR: d ¼ 1.16 (3 H, t, J 7.1 Hz, Me-CH2), 1.20–1.85 (10 H, m, 5 CH2),
3
3
3
1.36 (3 H, t, J 7.1 Hz, Me-CH2), 3.32 (1 H, m, H-CN), 4.07 (2 H, q, J 7.1 Hz,

790
B. MOHTAT ET AL.
3
CH2O), 4.38 (2 H, m, CH2O), 6.56 (1 H, d, J 7.8 Hz, CH), 6.85 (1 H, s, CH), 7.42
(1 H, t, 3J 7.9 Hz, CH), 7.48 (1 H, d, 3J 7.7 Hz, CH), 7.62 (1 H, t, 3J 7.9 Hz, CH), 7.96
(1 H, d, 3J 7.8 Hz, CH), 8.33 (1 H, d, 3J 8.0 Hz, CH). 13C NMR: d ¼ 14.1 (Me-CH2),
14.2 (Me-CH2), 24.1 (CH2), 24.3 (CH2), 25.8 (CH2), 33.1 (CH2), 33.4 (CH2), 60.2
=
=
=
(CꢀN), 61.3 (CH2O), 62.3 (CH2O), 106.8 (CH ), 125.3 (CH ), 126.0 (CH ),
=
=
=
=
=
=
126.3 (C ), 126.9 (CH ), 128.3 (CH ), 129.6 (CH ), 133.1 (CH ), 137.3 (C ),
=
=
=
=
=
141.2 (C ), 147.8 (C N), 162.1 (C O), 163.3 (C O), 164.2 (C O).
Di-t-butyl 2-{(cyclohexylimino)[1-oxoisoquinolin-1(2H)-yl]methyl}but-
2-enedioate (4j). Yellow powder; yield: 0.82 g (84%), mp 181–184 ꢁC. IR (KBr)
(tmax=cmꢀ1): 1725 (C O), 1662 (C O), 1626 (C N). MS (EI, 70 eV): m=z (%):
480 (Mþ, 11), 336 (37), 253 (48), 227 (100), 144 (45), 83 (47), 57 (35). Anal. calcd.
for C28H36N2O5 (480.60): C, 69.98; H, 7.55; N, 5.83. Found; C, 69.94; H, 7.58; N,
=
=
=
1
5.79. H NMR: d ¼ 1.29–1.85 (10 H, m, 5 CH2), 1.29 (9 H, s, Me3C), 1.55 (9 H, s,
3
Me3C), 3.32–3.35 (1 H, m, N-CH), 6.51 (1 H, d, J 7.8 Hz, CH), 6.74 (1 H, s,
3
CH), 7.41 (1 H, t, J 8.0 Hz, CH), 7.46 (1 H, d, J 7.7 Hz, CH), 7.60 (1 H, t,
3
3
3
3J 7.8 Hz, CH), 8.02 (1 H, d, J 7.8 Hz, CH), 8.34 (1 H, d, J 8.0 Hz, CH). 13C
NMR: d ¼ 24.2 (CH2), 24.3 (CH2), 25.8 (CH2), 27.9 (Me3C), 28.1 (Me3C), 33.1
=
(CH2), 33.5 (CH2), 59.9 (CꢀN), 81.7 (CꢀO), 82.6 (CꢀO), 106.4 (CH ), 125.8
=
(CH ), 126.6 (CH ), 126.7 (C ), 126.8 (CH ), 128.4 (CH ), 129.6 (CH ),
=
=
=
=
=
=
=
=
=
=
=
132.8 (CH ), 137.2 (C ), 140.9 (C ), 148.4 (C N), 161.8 (C O), 162.3 (C O),
=
163.7 (C O).
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