Mario Kröger et al.
FULL PAPERS
Ethyl 2-Cyano-N-(2,6-dimethylphenyl)ethanimidoate
(2c)
Ethyl 2-Cyano-3-[(2,6-dimethylphenyl)amino]-N-(2,6-
diisopropylphenyl)prop-2-enimidoate (3d)
A mixture of 2-cyano-N-(2,6-dimethylphenyl)acetamide (1a)
(10.00 g, 53 mmol) and a 1.0M solution of triethyloxonium
tetrafluoroborate in dichloromethane (60 mL, 60 mmol) was
stirred for 5 d at ambient temperature. The solvent was re-
moved in vacuum and the residue was washed twice with
absolute diethyl ether. Then the residue was taken up in
60 mL of absolute diethyl ether and cooled to 08C. Triethyl-
amine (8.4 mL, 60 mmol) was slowly added, and the mixture
was stirred at room temperature for 2 h. The organic phase
was separated and the residue was washed three times with
absolute diethyl ether. The diethyl ether solutions were col-
lected, dried over Na2SO4, and the solvent was removed
under reduced pressure. Extraction with hexane (4×15 mL)
gave the pure product; yield: 2.2 g (10.2 mmol, 19%).
A mixture of ethyl 2-cyano-N-(2,6-diisopropylphenyl)ethan-
imidoate (2a) (1.36 g, 5 mmol), triethyl orthoformate (0.74 g,
5 mmol), and acetic anhydride (1.13 g, 11 mmol) was re-
fluxed for 5 h. The solvent was removed under reduced
pressure. The resulting thick oil was dissolved in methanol
(6 mL), 2,6-dimethylaniline (0.61 g, 5 mmol) was added and
the solution was refluxed for 30 min. The reaction mixture
was then stored overnight at 58C and the product crystal-
lized. Recrystallization from methanol furnished colorless
crystals of the product; yield: 0.60 g (1.49 mmol, 30%).
Ethyl 2-Cyano-3-[(2,6-diisopropylphenyl)amino]-N-
(2,6-dimethylphenyl)prop-2-enimidoate (3e)
A mixture of ethyl 2-cyano-N-(2,6-methylphenyl)ethanimi-
doate (2c) (3.93 g, 18 mmol), triethyl orthoformate (2.66 g,
18 mmol), and acetic anhydride (4.08 g, 40 mmol) was re-
fluxed for 5 h. The solvent was removed under reduced
pressure. The resulting thick oil was dissolved in methanol
(15 mL), 2,6-diisopropylaniline (3.05 g, 17 mmol) was added
and the solution was refluxed for 30 min. The reaction mix-
ture was then stored overnight at 58C and the product crys-
tallized. Recrystallization from methanol furnished colorless
crystals of the product; yield: 2.09 g (5.2 mmol, 30%).
Ethyl 2-Cyano-3-[(2,6-diisopropylphenyl)amino]-N-
(2,6-diisopropylphenyl)prop-2-enimidoate (3a)
A mixture of ethyl 2-cyano-N-(2,6-diisopropylphenyl)ethan-
imidoate (2a) (1.18 g, 4.2 mmol), triethyl orthoformate
(0.61 g, 4.2 mmol), and acetic anhydride (1.47 g, 8.4 mmol)
was refluxed for 5 h. The solvent was removed under re-
duced pressure. The resulting thick oil was dissolved in
methanol (5 mL), 2,6-diisopropylaniline (0.93 g, 4.7 mmol)
was added and the solution was refluxed for 30 min. The re-
action mixture was then stored overnight at 58C and the
product crystallized. Recrystallization from methanol fur-
nished colorless crystals of the product; yield: 0.77 g
(1.68 mmol, 42%).
Ethyl 2-Cyano-3-[(2,6-diethylphenyl)amino]-N-(2,6-
diethylphenyl)prop-2-enimidoate (3f)
A mixture of ethyl 2-cyano-N-(2,6-diethylphenyl)ethanimi-
doate (2b) (2.5 g, 10.2 mmol), triethyl orthoformate (1.51 g,
10.2 mmol), and acetic anhydride (2.25 g, 16.6 mmol) was re-
fluxed for 5 h. The solvent was removed under reduced
pressure. The resulting thick oil was dissolved in methanol
(5 mL), 2,6-diethylaniline (1.49 g, 10 mmol) was added and
the solution was refluxed for 30 min. The reaction mixture
was then stored overnight at 58C and the product crystal-
lized. Recrystallization from methanol furnished colorless
crystals of the product; yield: 1.13 g (2.82 mmol, 28%).
Ethyl 2-Cyano-3-[(2,6-diethylphenyl)amino]-N-(2,6-
diisopropylphenyl)prop-2-enimidoate (3b)
A mixture of ethyl 2-cyano-N-(2,6-diisopropylphenyl)ethan-
imidoate (2a) (1.5 g, 5.5 mmol), triethyl orthoformate
(0.82 g, 5.5 mmol), and acetic anhydride (1.17 g, 11.5 mmol)
was refluxed for 5 h. The solvent was removed under re-
duced pressure. The resulting thick oil was dissolved in
methanol (7 mL), 2,6-diethylaniline (0.82 g, 5.5 mmol) was
added and the solution was refluxed for 30 min. The reac-
tion mixture was then stored overnight at 58C and the prod-
uct crystallized. Recrystallization from methanol furnished
colorless crystals of the product; yield: 0.74 g (1.7 mmol,
31%).
Ethyl 2-Cyano-3-[(2,6-dichlorophenyl)amino]-N-(2,6-
dimethylphenyl)prop-2-enimidoate (3g)
A mixture of ethyl-2-cyano-N-(2,6-methylphenyl)ethanimi-
doate (2a) (1.56 g, 3.3 mmol), triethyl orthoformate (0.49 g,
3.3 mmol), and acetic anhydride (0.71 g, 7 mmol) was re-
fluxed for 5 h. The solvent was removed under reduced
pressure. The resulting thick oil was dissolved in methanol
(2 mL), 2,6-dichloroaniline (0.54 g, 3.3 mmol) was added
and the solution was refluxed for 30 min. The reaction mix-
ture was then stored overnight at 58C and the product crys-
tallized. Recrystallization from methanol furnished colorless
crystals of the product; yield: 0.60 g (1.3 mmol, 41%).
Ethyl 2-Cyano-3-[(2,6-diisopropylphenyl)amino]-N-
(2,6-diethylphenyl)prop-2-enimidoate (3c)
A mixture of ethyl 2-cyano-N-(2,6-diethylphenyl)ethanimi-
doate (2b) (2 g, 8.15 mmol), triethyl orthoformate (1.2 g,
8.15 mmol), and acetic anhydride (1.68 g, 16.6 mmol) was re-
fluxed for 5 h. The solvent was removed under reduced
pressure. The resulting thick oil was dissolved in methanol
(7 mL), 2,6-diisopropylaniline (0.93 g, 5.88 mmol) was added
and the solution was refluxed for 30 min. The reaction mix-
ture was then stored overnight at 58C and the product crys-
tallized. Recrystallization from methanol furnished colorless
crystals of the product; yield: 0.98 g (2.26 mmol, 28%).
Ethyl 3-[(2,6-Diisopropylphenyl)amino]-2-{[(2,6-
diisopropylphenyl)amino]carbonyl}acrylate (2h)
A mixture of diethyl ethoxymethylenemalonate (5.01 g,
23 mmol) and 2,6-diisopropylaniline (9.04 g, 46 mmol) was
heated at 1358C for 38 h; the produced ethanol was distilled
out of the reaction mixture. The mixture was cooled and
1916
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2006, 348, 1908 – 1918
Kroeger, Mario
