Highly Efficient Copper-Catalyzed Dehydrogenative Cross-Coupling of Azoles with α-Amino Carbonyl Compounds

Article abstract of DOI:10.1055/a-1331-7285

A novel and highly efficient dehydrogenative cross-coupling- reaction between α-amino carbonyl compounds and azoles by copper catalysis using di- tert -butyl peroxide (DTBP) as an oxidant is described-. A diverse range of azoles undergo the dehydrogenative imidoylation smoothly with various α-amino carbonyl compounds for the exclusive formation of the corresponding N -imidoyl azoles in high yields under air. The synthetic method has the advantages of good functional-group tolerance, wide substrate scope, excellent yields, and simple operation-, thus providing a convenient and practical protocol for the synthesis of functionalized azoles.

Full text of DOI:10.1055/a-1331-7285

SYNTHESIS
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Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart
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021, 53, A–I
paper
A
de
Synthesis
J.-J. Ji et al.
Paper
Highly Efficient Copper-Catalyzed Dehydrogenative Cross-Coupling
of Azoles with -Amino Carbonyl Compounds
Jiu-Jian Jib
Zhi-Qiang Zhu*a,b
Zong-Bo Xieb
Juan Tangc
R3
Z
Y
O
X
X
CuCl (5 mol%)
DTBP (2 equiv)
H
Y
Z
N
N
N
H
R2
+
R2
R1
PhCl, 110 °C
N
H
En Yuand
R3
O
Zhang-Gao Le*b
R1
a
good functional-group tolerance
broad substrate scope
high yields
Jiangxi Province Key Laboratory of Polymer Micro/Nano
Manufacturing and Devices, East China University of Technology,
Nanchang, 330013, P. R. of China
simple operation
28 examples
up to 99% yield
zhuzq@ecut.edu.cn
School of Chemistry, Biology and Material Science, East China
b
University of Technology, Nanchang, 330013, P. R. of China
zhgle@ecut.edu.cn
Ministry of Education Key Laboratory of Functional Small Organic
c
Molecule, Department of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, 330022, P. R. of China
College of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, P. R. of China
d
Correponding Authors
Received: 05.12.2020
Accepted after revision: 07.12.2020
Published online: 07.12.2020
N–H of azoles has been widely investigated by many re-
search groups. Despite these achievements, exploring nov-
5
DOI: 10.1055/a-1331-7285; Art ID: ss-2020-f0477-op
el and highly efficient methods for the synthesis of poten-
tially useful organic compounds remains highly desirable.
Abstract
A novel and highly efficient dehydrogenative cross-
-Amino carbonyl groups are ubiquitous structural mo-
coupling reaction between -amino carbonyl compounds and azoles by
copper catalysis using di-tert-butyl peroxide (DTBP) as an oxidant is
described. A diverse range of azoles undergo the dehydrogenative imi-
doylation smoothly with various -amino carbonyl compounds for the
exclusive formation of the corresponding N-imidoyl azoles in high yields
under air. The synthetic method has the advantages of good functional-
group tolerance, wide substrate scope, excellent yields, and simple
operation, thus providing a convenient and practical protocol for the
synthesis of functionalized azoles.
tifs in many natural products, biologically active molecules,
6
,7
and functional materials. Direct functionalization of the
3
-C(sp )–H in -amino carbonyl compounds with different
coupling partners to give -substituted -amino carbonyl
compounds has attracted considerable attention in the past
8
–10
several years.
However, the employment of -amino car-
bonyl compounds to produce a C–N double bond and a new
chemical bond through dehydrogenative cross-coupling has
rarely been studied. In 2012, Li’s group found an oxidative
Key words copper, dehydrogenation, imidoylation, azoles, -amino
ketones

-arylation of -amino carbonyl compounds with indoles to
generate -imino and -oxocarbonyl products by the catal-
The construction of C–N bonds is of significant impor-
ysis of CuCl/TBHP system under argon and air, respective-
1
1a
tance because of the widespread presence of nitrogen-con-
taining compounds in a variety of natural products as well
as in synthetic organic molecules that possessing diverse
ly. In 2016, Huang et al. reported a copper-catalyzed oxi-
dative cross-coupling of -amino ketones and amines to
give -imino and -oxocarbonyl compounds under air and
1
11b
biological activities. Azoles are biologically important ni-
oxygen atmosphere, respectively. Later, Yi and co-work-
11c
trogen heterocyclic compounds that exist widely in nature
and are often useful as drugs, enzyme inhibitors, supramo-
ers revealed oxidative cross-coupling reactions between
-amino carbonyl compounds and primary amines to af-
ford 2-amino-2-iminocarbonyl compounds. However, di-
rect N-H imidoylation of azoles by using -amino carbonyl
compounds as imine precursors for the exclusive formation
of N-imidoyl azoles under air conditions through a C-H/N-H
oxidation strategy remains unknown. In consideration of
the biologically importance of N-substituted azoles, and as
a continuation of our efforts on direct C–H cross-coupling
2
lecular ligands, catalysts and ionic liquids etc. Traditional
methods to access N-substituted azoles mainly involve nuc-
leophilic substitution of azoles with alkyl or alkenyl (pseu-
do) halides under basic conditions. In the past few years,
dehydrogenative cross-coupling reactions have been con-
sidered a valuable and attractive synthetic strategy to form
C–C and C–heteroatom bonds because these reactions do
not require prefunctionalization of substrates, and also take
9
reactions, we herein present a novel and highly efficient
3
advantage of atom- and step-economy. Among them, di-
dehydrogenative cross-coupling reaction of azoles with -
amino carbonyl compounds to synthesize N-imidoyl azoles
by copper catalysis using di-tert-butyl peroxide (DTBP) as
an oxidant.
rect functionalization of various C–H bonds with N–H of
azoles to construct C–N bonds has attracted much atten-
4
,5
tion. In recent years, transition-metal-catalyzed oxidative
3
amination of C(sp )–H bonds adjacent to a heteroatom with
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2020. Thieme. All rights reserved. Synthesis 2021, 53, A–I
Georg Thieme Verlag KG, Rüdigerstraße 14, 70469 Stuttgart, Germany

B
Synthesis
J.-J. Ji et al.
Paper
Our initial study commenced with 1-phenyl-2-(p-tolyl-
amino)ethan-1-one (1a) and benzimidazole (2a) as model
substrates to investigate the dehydrogenative cross-cou-
pling reaction. When the reaction was performed in the
sively in 75% isolated yield. A variety of transition-metal
catalysts were then examined, and CuCl exhibited the best
catalytic efficiency for the yield of product 3aa (compare
entries 1–7 with entry 8; see also the Supporting Informa-
tion). In the absence of catalyst, only a trace amount of
product 3aa was observed (entry 9). A series of oxidants
were examined; other oxidants including tert-butyl hy-
droperoxide (TBHP), tert-butyl perbenzoate (TBPB), di-
presence of 5 mol% Cu(OAc) and 2 equivalents di-tert-butyl
2
peroxide (DTBP) in PhCl at 120 °C under air (Table 1, entry
1
), the expected coupling product 3aa was obtained exclu-
cumyl peroxide (DCP), benzoyl peroxide (BPO) and O gave
inferior yields of product 3aa (compare product 3aa in en-
2
Table 1 Optimization of the Reaction Conditionsa
try 18 with entry 8).
O
H
N
CuCl
5 mol%)
DTBP
N
N
(
O
H
N
H
N
N
N
R2
1
a
a
(2 equiv)
catalyst, oxidant
solvent, temp
R1
R2+
+
N
N
N
PhCl
H
N
O
O
1
10 °C
air
1
a–q
2a
R1
3
aa
3aa–qa
N
2
N
N
N
Entry
Catalyst
Cu(OAc)
Oxidant
Solvent
Yield (%)b
N
N
N
1
2
3
4
5
6
7
8
9
2
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
TBHP
TBPB
DCP
PhCl
PhCl
PhCl
PhCl
PhCl
PhCl
PhCl
PhCl
PhCl
PhCl
PhCl
PhCl
PhCl
PhCl
PhMe
MeCN
DMSO
PhCl
PhCl
PhCl
PhCl
PhCl
75
63
72
80
73
79
78
82
trace
56
69
68
69
60
45
65
23
N
N
N
O
O
O
Cu(OTf)
Cu
CuCl
2
2
O
3
aa 93%
3ba 94%
3ca 94%
2
N
N
CuBr
2
N
N
CuI
N
N
CuBr
CuCl
–c
N
R
N
N
O
O
O
3
ea R = F 85%
3fa R = Cl 94%
ga R = Br 95%
3ha R = I 93%
3
3
da 83%
3ia 85%
1
1
1
1
1
1
1
1
1
1
2
2
0
CuCl
CuCl
CuCl
CuCl
CuCl
CuCl
CuCl
CuCl
CuCl
CuCl
CuCl
CuCl
CuCl
CN
1
N
N
N
OMe
2
R
N
N
N
3
BPO
N
N
N
4
O
2
O
O
O
5
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
3
ka R = Me 94%
3la R = OMe 99%
ma R = F 90%
6
3
CF3
3ja 80%
3na 97%
7
d
e
8
73 (75)
N
N
N
9f
0g
1h
2i
85
89
67
93
N
N
N
O
N
N
N
O
O
O
2
a
Reaction conditions: 1a (0.26 mmol), 2a (0.2 mmol), catalyst (5 mol%),
3
qa 17%
3
oa 95%
3pa 98%
oxidant (2 equiv), solvent (2 mL) in air at 110 °C, 2–3 h.
b
Isolated yield based on 2a.
In the absence of a catalyst.
DTBP (1 equiv).
DTBP (3 equiv).
At 90 °C.
c
Scheme 1 CDC Reaction between -amino carbonyl compounds 1 and
2a by copper catalysis. Reagents and conditions: 1 (0.4 mmol), 2a
(0.2 mmol), CuCl (5 mol%), DTBP (2 equiv), PhCl (2 mL) in air at 110 °C
for 2–3 h. Isolated yield based on 2a.
d
e
f
g
h
i
At 120 °C.
1
a (1 equiv).
1
a (2 equiv).
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2020. Thieme. All rights reserved. Synthesis 2021, 53, A–I

C
Synthesis
J.-J. Ji et al.
Paper
Further screening revealed that lowering the tempera-
ture to 110 °C was beneficial to the reaction, affording the
coupling product 3aa in 89% yield (cf. Table 1, entries 8, 19
with entry 20). Increasing the amount of 1a from 1.3 to 2.0
equivalents led to the formation of the desired product 3aa
with a yield of 93% (cf. entries 20 and 21 with entry 22). Af-
ter exploring different parameters, the optimized reaction
conditions were established as 5 mol% CuCl and 2.0 equiva-
lents DTBP in PhCl at 110 °C.
With the optimized N-H imidoylation reaction condi-
tions in hand, a range of -amino carbonyl compounds 1
were examined in the cross-dehydrogenative coupling
(CDC) reaction with 1H-benzimidazole (2a). As shown in
Scheme 1, a wide range of -amino ketones 1a–p under-
went the coupling reaction well with 1H-benzimidazole
(2a) to afford the desired corresponding products 3aa–pa in
80–99% yields. The experimental results revealed that
-amino ketones 1a–j, bearing either electron-rich or
R3
Z
Y
X
N
O
H
H
N
CuCl (5 mol%)
DTBP (2 equiv)
N
N
R3
+
X
Z
O
Y
PhCl, 110 °C, air
1a
2a–l
3aa–al
N
N
N
N
N
N
N
N
N
N
N
N
O
O
O
O
3aa 93%
R
3ab 77%
3ac/3ac' = 1:1, 86%
MeO
Cl
N
N
N
N
MeO
Cl
N
N
N
N
N
N
N
N
O
O
O
O
3ad/3ad' = 1:1, 90%
3
ae/3ae' = 1:1, 97%
Br
N
N
N
N
Br
N
N
N
N
N
N
N
N
O
O
O
O
3af/3af' = 1:1, 95%
3ag 71%
3ah 63%
I
O
N
N
N
N
N
N
N
N
N
N
N
N
O
O
O
O
3ai 43%
3aj 94%
3ak 42%
3al 53%
Scheme 2 CDC Reaction between -amino ketone 1a and azoles 2 by copper catalysis. Reagents and conditions: 1a (0.4 mmol), 2 (0.2 mmol), CuCl
5 mol%), DTBP (2 equiv), PhCl (2 mL) in air at 110 °C for 2–3 h. Isolated yield based on 2.
(
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2020. Thieme. All rights reserved. Synthesis 2021, 53, A–I

D
Synthesis
J.-J. Ji et al.
Paper
electron-deficient N-aryl groups, underwent the reaction
smoothly with benzimidazole 2a to furnish the correspond-
ing products in high yields.
conducted under the standard conditions. The experimen-
tal results demonstrated that -amino ketone 1a could be
converted into imine intermediate 4 efficiently, based on
GC-MS trace analysis (Scheme 3, eq. 1a). Next, when the re-
action of imine 4 with 1H-benzimidazole 2a was carried
out under the current conditions, product 3aa was isolated
in 65% yield in the absence of DTBP (Scheme 3, eq. 1b). Fur-
thermore, when a stoichiometric amount of radical inhibi-
tor, TEMPO (2,2,6,6-tetramethylpiperidinyloxy) or BHT
(2,6-di-tert-butyl-4-methylphenol), was added into the
model reaction of -amino ketone 1a with 1H-benzimidaz-
ole 2a, product 3aa was obtained in 92% and 43% yield, re-
spectively. The coupling product 3aa was observed with a
yield of 90% when 2 equivalents TEMPO was used instead of
DTBP in the model reaction. These results imply that imine
4 is indeed the crucial intermediate, TEMPO might act as an
Among the methyl-substituted -amino ketones 1a–c,
irrespective of the position of the substituent, excellent
yields of the desired products 3aa–ca were achieved. Nota-
bly, synthetically useful halogen substituents (F, Cl, Br and I)
were well tolerated under the current conditions. The sub-
stitution effect on the aryl group, which connected with the
carbonyl in -amino ketones 1k–n was also tested. A series
of different substituents, such as methyl, methoxy and fluo-
ro, on the aryl group of the 1-arylethanone moiety, under-
went the reaction readily with 1H-benzimidazole (2a), re-
sulting in the corresponding products 3ka–na in high yields
under the optimal conditions. Furthermore, biphenyl and
naphthyl substituted -amino ketones 1o–p were also
found to be suitable for this transformation, leading to the
coupling products 3oa and 3pa in 95% and 98% yield, re-
spectively. The reaction of 1-phenyl-2-(p-tolylamino)-
ethan-1-one (4.4 mmol, 1 g) with 2a was also performed on
a gram scale, resulting in the desired product 3aa in 50%
yield (0.75 g). However, when N-arylglycine ethyl ester 1q
was used instead of 1a under the standard conditions, the
desired product 3qa was obtained in low yield.
12
oxidant, and that the copper salt plays an important role
in this coupling reaction.
O
O
H
N
CuCl (5 mol%)
DTBP (2 equiv)
N
(1a)
PhCl, 110 °C
1a
4
GC/MS analysis
O
To evaluate the scope and limitations of the present pro-
tocol, unsubstituted and various substituted azoles 2 were
investigated with 1-phenyl-2-(p-tolylamino)ethan-1-one
N
N
N
CuCl (5 mol%)
PhCl, 110 °C
4
+
(1b)
(
1a) under the optimized conditions; the results are shown
N
N
O
in Scheme 2. A variety of azoles 2a–l could be readily con-
verted into the corresponding coupling products 3aa–al
with 1-phenyl-2-(p-tolylamino)ethan-1-one (1a) in satis-
factory yields. The experimental results indicated that both
electron-donating and electron-withdrawing groups on
benzene rings of 1H-benzimidazoles 2b–f reacted well with
N
H
2a
3aa 65%
O
H
N
N
N
1
a, giving the desired products 3ab–af in high yields.
CuCl (5 mol%)
DTBP (2 equiv)
1
a
Owing to the tautomerism, a mixture of unseparable re-
N
+
(1c)
gioisomers, with almost 1:1 ratio, was observed in excellent
overall yields from coupling 1a with C5/C6-substituted 1H-
benzimidazoles 2c–f including methyl, methoxy, chloro and
bromo. A range of imidazoles 2g–i, such as 2-methyl, 4-
methyl, and 4-iodoimidazole underwent the reaction
smoothly and were converted into the corresponding prod-
ucts 3ag–ai in good to excellent yields. In addition, other
azoles, such as 1H-pyrazole 2j and 1H-1,2,4-triazole 2k also
underwent coupling with 1a to generate the respective
coupled products 3aj and 3ak in 94% and 42% yield, respec-
tively. Interestingly, the optimized conditions also worked
with morpholine, giving rise to the desired coupling prod-
uct 3al in moderate yield.
To gain insight into the reaction mechanism, several
control experiments were performed; the results are sum-
marized in Scheme 3. According to the presented results of
the transformations, we thought that imine 4 might be a
key intermediate in the reaction. Thus, oxidation of -ami-
no ketone 1a in the absence of 1H-benzimidazole 2a was
N
PhCl, 110 °C
TEMPO or BHT (2 equiv)
O
N
H
3aa
2a
TEMPO (2 equiv): 92%
BHT (2 equiv): 43%
TEMPO (2 equiv), without DTBP: 90%
Scheme 3 Control experiments
On the basis of the preliminary results and on precedent
reports,1 a plausible reaction mechanism for the dehydro-
genative imidoylation is depicted in Scheme 4. Firstly, a
tert-butoxyl radical, formed by the copper-catalyzed disso-
ciation of DTBP, may abstract an -hydrogen atom of -ami-
no ketone 1a to generate the radical intermediate 4. Subse-
quently, the imine intermediate 5 is generated by a single-
electron transfer (SET) from copper(II) to copper(I) and
deprotonation process with tert-butoxyl anion, and then
the copper salt coordinates with imine intermediate 5 to
1
1
1a–c
provide the activated copper complex 6.
Finally, benz-
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2020. Thieme. All rights reserved. Synthesis 2021, 53, A–I

E
Synthesis
J.-J. Ji et al.
Paper
t
t
BuOO Bu
CuI
CuII + tBuO–
O
O
O
H
CuII + tBuO–
N
H
N
tBuO
N
– tBuOH
CuI
tBuOH
+
5
1
a
4
H
N
[Cu]
O
N
N
N
N
N
2a
[
Cu]
O
6
3aa
Scheme 4 Plausible mechanism
imidazole 2a undergoes coupling with copper complex 6,
giving the desired coupling product 3aa, and copper(I) can
be oxidized to copper(II) to complete the cycle by either
DTBP or molecular oxygen in air.
2-(1H-Benzo[d]imidazol-1-yl)-1-phenyl-2-(p-tolylimino)ethan-1-
one (3aa)
Yield: 93% (63.1 mg); yellow solid; mp 132.7–133.2 °C.
1
H NMR (400 MHz, CDCl ):  = 8.48–8.33 (m, 1 H), 8.06 (s, 1 H), 7.84
3
In conclusion, we have developed a novel and efficient
copper-catalyzed direct dehydrogenative N-imidoylation of
azoles with -amino carbonyl compounds using di-tert-bu-
tyl peroxide (DTBP) as an oxidant. A broad range of azoles
undergo the dehydrogenative cross-coupling well with var-
ious -amino carbonyl compounds to afford the corre-
sponding functionalized N-imidoyl azoles exclusively in
good to excellent yields under air. The advantages of this
methodology are the good functional-group tolerance,
wide substrate scope, excellent yields and simple operation.
The approach holds potential for use in the synthesis of nat-
ural products and biologically active molecules.
(t, J = 6.8 Hz, 3 H), 7.56 (t, J = 7.4 Hz, 1 H), 7.46–7.32 (m, 4 H), 6.97 (d,
J = 8.1 Hz, 2 H), 6.86 (d, J = 8.2 Hz, 2 H), 2.19 (s, 3 H).
13C NMR (100 MHz, CDCl
1
1
):  = 190.7, 148.4, 144.3, 142.8, 141.4,
35.5, 134.9, 133.5, 131.6, 129.6, 129.6, 129.3, 125.3, 124.8, 121.2,
20.6, 115.9, 20.8.
3
HRMS (ESI): m/z [M + H]+ calcd for C22H18N O: 340.1444; found:
3
3
40.1447.
2
-(1H-Benzo[d]imidazol-1-yl)-1-phenyl-2-(m-tolylimino)ethan-1-
one (3ba)
Yield: 94% (63.8 mg); yellow oil.
1
H NMR (400 MHz, CDCl ):  = 8.46–8.36 (m, 1 H), 8.07 (s, 1 H), 7.84
3
(
dd, J = 12.4, 5.6 Hz, 3 H), 7.56 (t, J = 7.4 Hz, 1 H), 7.47–7.35 (m, 4 H),
7
.04 (t, J = 7.8 Hz, 1 H), 6.77 (dd, J = 18.0, 7.2 Hz, 3 H), 2.21 (s, 3 H).
1
3
C NMR (100 MHz, CDCl ):  = 190.3, 148.5, 145.3, 144.3, 141.4,
3
Unless otherwise indicated, all reagents were purchased from com-
1
1
38.9, 135.5, 133.6, 131.6, 129.6, 129.2, 128.8, 126.0, 125.3, 124.9,
22.0, 120.6, 118.2, 115.9, 21.2.
1
mercial distributors and used without further purification. H NMR
and 13C NMR spectra were recorded at 400 or 500 MHz and 100 or
HRMS (ESI): m/z [M + H]+ calcd for C22H18N O: 340.1444; found:
3
3
1
25 MHz, respectively, using tetramethylsilane as an internal refer-
40.1444.
ence. High-resolution mass spectra (HRMS) were measured with a
quadrupole time-of-flight (Q-TOF) mass spectrometer instrument
with an electrospray ionization (ESI) source. Melting points are un-
corrected. Flash column chromatography was performed over silica
gel 200–300 mesh. -Amino carbonyl compounds 1 were prepared
2-(1H-Benzo[d]imidazol-1-yl)-1-phenyl-2-(o-tolylimino)ethan-1-
one (3ca)
Yield: 93% (63.8 mg); yellow oil.
9
according to the reported protocols.
1
H NMR (400 MHz, CDCl ):  = 8.59–8.45 (m, 1 H), 8.09 (s, 1 H), 7.92–
3
7
7
.83 (m, 1 H), 7.79 (d, J = 7.6 Hz, 2 H), 7.56 (t, J = 7.2 Hz, 1 H), 7.48–
.35 (m, 4 H), 7.06 (d, J = 7.2 Hz, 1 H), 6.92 (dt, J = 20.8, 7.2 Hz, 2 H),
Synthesis of Product 3; General Procedure
To a mixture of -amino carbonyl compound 1 (0.40 mmol) and azole
6.74 (d, J = 7.6 Hz, 1 H), 2.33 (s, 3 H).
2
(0.20 mmol) in chlorobenzene (2 mL) was added CuCl (0.01 mmol,
13
C NNMR (100 MHz, CDCl ):  = 190.3, 148.2, 144.3, 143.9, 141.5,
3
1.0 mg) and DTBP (0.4 mmol, 58.5 mg). The reaction mixture was
1
1
35.5, 133.8, 131.7, 130.5, 129.9, 129.2, 129.2, 126.2, 125.4, 124.9,
20.7, 120.0, 115.9, 18.4.
then stirred at 110 °C oil bath. After the reaction was complete, the
resulting mixture was concentrated under vacuum and the residue
was purified by preparative TLC on silica, eluting with petroleum
ether (60–90 °C)/ethyl acetate (4:1, v/v) to afford the desired coupling
product 3.
HRMS (ESI): m/z [M + H]+ calcd for C22H18N O: 340.1444; found:
3
3
40.1446.
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2020. Thieme. All rights reserved. Synthesis 2021, 53, A–I

F
Synthesis
J.-J. Ji et al.
Paper
2
-(1H-Benzo[d]imidazol-1-yl)-1-phenyl-2-(phenylimino)ethan-1-
HRMS (ESI): m/z calcd for C21H15IN O: 452.0254; found: 452.0257.
3
1
3
one (3da)
Yield: 83% (54.0 mg); yellow solid; mp 114.4–115.9 °C.
4-((1-(1H-Benzo[d]imidazol-1-yl)-2-oxo-2-phenylethylidene)-
1
amino)benzonitrile (3ia)
H NMR (400 MHz, CDCl ):  = 8.49–8.38 (m, 1 H), 8.08 (s, 1 H), 7.89–
3
7.76 (m, 3 H), 7.55 (t, J = 7.4 Hz, 1 H), 7.46–7.34 (m, 4 H), 7.17 (t, J = 7.7
Yield: 85% (59.7 mg); yellow solid; mp 141.3–142.1 °C.
Hz, 2 H), 6.97 (dd, J = 13.3, 7.5 Hz, 3 H).
1
H NMR (400 MHz, CDCl ):  = 8.41–8.32 (m, 1 H), 8.05 (s, 1 H), 7.84
3
1
3
C NMR (100 MHz, CDCl ):  = 190.3, 148.8, 145.4, 144.3, 141.4,
(ddd, J = 15.5, 6.1, 1.8 Hz, 3 H), 7.63 (t, J = 7.5 Hz, 1 H), 7.48–7.42 (m, 6
3
1
1
35.6, 133.5, 131.6, 129.6, 129.3, 129.0, 125.4, 125.2, 124.9, 121.2,
20.7, 116.0.
H), 7.04–6.98 (m, 2 H).
13
C NMR (100 MHz, CDCl ):  = 188.8, 149.8, 149.6, 144.3, 141.3,
3
HRMS (ESI): m/z [M + H]+ calcd for C21H16N O: 326.1288; found:
136.2, 133.1, 133.1, 131.3, 129.6, 125.8, 125.5, 121.8, 120.9, 118.6,
115.9, 114.4, 108.5.
3
326.1291.
HRMS (ESI): m/z [M + H]+ calcd for C22H15N O: 351.1240; found:
4
2
-(1H-Benzo[d]imidazol-1-yl)-2-((4-fluorophenyl)imino)-1-
351.1241.
phenylethan-1-one (3ea)
Yield: 85% (58.3 mg); yellow solid; mp 133.4–135.7 °C.
2-(1H-Benzo[d]imidazol-1-yl)-1-phenyl-2-((4-(trifluoromethyl)-
1
phenyl)imino)ethan-1-one (3ja)
H NMR (400 MHz, CDCl ):  = 8.47–8.35 (m, 1 H), 8.07 (s, 1 H), 7.90–
3
7.77 (m, 3 H), 7.58 (t, J = 7.4 Hz, 1 H), 7.47–7.37 (m, 4 H), 7.02–6.77
Yield: 80% (62.9 mg); yellow solid; mp 132.0–132.7 °C.
(
1
m, 4 H).
1
H NMR (400 MHz, CDCl ):  = 8.40 (dd, J = 6.4, 3.2 Hz, 1 H), 8.06 (s, 1
3
3
C NMR (100 MHz, CDCl ):  = 190.3, 160.3 (d, J = 243.4 Hz), 149.3,
H), 7.90–7.78 (m, 3 H), 7.60 (t, J = 7.4 Hz, 1 H), 7.44 (q, J = 6.8 Hz, 6 H),
3
1
1
44.4, 141.6, 141.5, 141.4, 135.8, 133.3, 131.5, 129.5 (d, J = 18.4 Hz),
25.4, 125.01, 122.7 (d, J = 8.3 Hz), 120.7, 115.9 (d, J = 2.3 Hz), 115.7.
7.03 (d, J = 8.0 Hz, 2 H).
13
C NMR (100 MHz, CDCl ):  = 189.2, 149.7, 148.6, 144.3, 141.3,
3
HRMS (ESI): m/z [M + H]+ calcd for C21H15FN O: 344.1194; found:
136.0, 133.3, 131.4, 129.6, 129.5, 127.1 (q, J = 32.7 Hz), 126.2 (q, J = 7.4
Hz), 125.6, 125.3, 124.0 (q, J = 272.8 Hz),121.3, 120.8, 115.9.
3
344.1196.
HRMS (ESI): m/z [M + H]+ calcd for C22H15F N O: 394.1162; found:
3
3
2
-(1H-Benzo[d]imidazol-1-yl)-2-((4-chlorophenyl)imino)-1-
394.1158.
phenylethan-1-one (3fa)
Yield: 94% (67.5 mg); yellow solid; mp 124.8–126.6 °C.
2-(1H-Benzo[d]imidazol-1-yl)-1-(p-tolyl)-2-(p-tolylimino)ethan-
1
1-one (3ka)
H NMR (400 MHz, CDCl ):  = 8.40 (dd, J = 7.6, 3.6 Hz, 1 H), 8.05 (s, 1
3
H), 7.91–7.75 (m, 3 H), 7.60 (t, J = 7.4 Hz, 1 H), 7.49–7.36 (m, 4 H), 7.14
Yield: 94% (66.4 mg); yellow solid; mp 131.9–132.9 °C.
(
1
d, J = 8.4 Hz, 2 H), 6.89 (d, J = 8.4 Hz, 2 H).
1
H NMR (400 MHz, CDCl ):  = 8.48–8.30 (m, 1 H), 8.06 (s, 1 H), 7.88–
3
3
C NMR (100 MHz, CDCl ):  = 189.9, 149.3, 144.4, 144.0, 141.3,
7.78 (m, 1 H), 7.73 (d, J = 8.0 Hz, 2 H), 7.47–7.35 (m, 2 H), 7.18 (d, J =
8.0 Hz, 2 H), 6.97 (d, J = 8.0 Hz, 2 H), 6.88 (d, J = 8.0 Hz, 2 H), 2.34 (s, 3
H), 2.20 (s, 3 H).
3
1
1
35.9, 133.3, 131.5, 130.7, 129.6, 129.5, 129.1, 125.5, 125.1, 122.6,
20.7, 115.9.
HRMS (ESI): m/z [M + H]+ calcd for C21H15ClN O: 360.0898; found:
13C NMR (100 MHz, CDCl
141.5, 134.8, 131.6, 131.1, 130.1, 129.8, 129.6, 125.3, 124.8, 121.2,
20.6, 115.9, 21.9, 20.8.
):  = 190.1, 148.6, 147.1, 144.3, 142.9,
3
3
360.0896.
1
2
-(1H-Benzo[d]imidazol-1-yl)-2-((4-bromophenyl)imino)-1-
HRMS (ESI): m/z [M + H]+ calcd for C23H20N O: 354.1601; found:
3
phenylethan-1-one (3ga)
354.1600.
Yield: 95% (76.6 mg); yellow solid; mp 135.1–136.9 °C.
1
2-(1H-Benzo[d]imidazol-1-yl)-1-(4-methoxyphenyl)-2-(p-tolyl-
imino)ethan-1-one (3la)
H NMR (400 MHz, CDCl ):  = 8.45–8.35 (m, 1 H), 8.05 (s, 1 H), 7.89–
.79 (m, 3 H), 7.59 (t, J = 7.4 Hz, 1 H), 7.42 (dd, J = 10.0, 3.6 Hz, 4 H),
.28 (t, J = 6.8 Hz, 2 H), 6.83 (d, J = 8.8 Hz, 2 H).
3
7
7
Yield: 99% (73.1 mg); yellow solid; mp 135.9–136.8 °C.
1
3
1H NMR (400 MHz, CDCl
C NMR (100 MHz, CDCl ):  = 189.8, 149.3, 144.5, 144.3, 141.3,
3
):  = 8.33 (d, J = 9.2 Hz, 1 H), 8.06–7.96 (m, 2
3
1
1
35.9, 133.3, 132.1, 131.5, 129.6, 129.5, 125.5, 125.1, 122.9, 120.7,
18.4, 115.9.
H), 7.91 (s, 1 H), 7.83 (d, J = 7.6 Hz, 4 H), 7.71 (d, J = 8.8 Hz, 1 H), 7.56
(t, J = 7.4 Hz, 2 H), 7.39 (td, J = 7.6, 2.4 Hz, 4 H), 7.32 (d, J = 2.4 Hz, 1 H),
7.09–7.00 (m, 2 H), 6.96 (t, J = 6.6 Hz, 4 H), 6.86 (dd, J = 8.0, 5.2 Hz, 4
H), 3.88 (d, J = 6.4 Hz, 6 H), 2.19 (d, J = 2.8 Hz, 6 H).
HRMS (ESI): m/z [M + H]+ calcd for C21H15BrN O: 404.0393; found:
3
404.0395.
1
3
C NMR (100 MHz, CDCl ):  = 188.6, 165.5, 148.7, 144.3, 143.0,
3
1
1
41.6, 134.8, 132.3, 131.7, 129.6, 126.5, 125.2, 124.7, 121.2, 120.5,
16.0, 114.7, 77.4, 77.1, 76.7, 55.7, 20.8.
2
-(1H-Benzo[d]imidazol-1-yl)-2-((4-iodophenyl)imino)-1-phenyl-
ethan-1-one (3ha)
HRMS (ESI): m/z [M + H]+ calcd for C23H20N O : 370.1550; found:
3
Yield: 93% (84.0 mg); yellow solid; mp 144.8–145.1 °C.
3
2
70.1554.
1
H NMR (400 MHz, CDCl ):  = 8.43–8.34 (m, 1 H), 8.04 (s, 1 H), 7.89–
3
7
.78 (m, 3 H), 7.60 (t, J = 7.4 Hz, 1 H), 7.52–7.37 (m, 6 H), 6.71 (d, J =
(
1H-Benzo[d]imidazol-1-yl)-1-(4-fluorophenyl)-2-(p-tolyl-
8.4 Hz, 2 H).
imino)ethan-1-one (3ma)
1
3
C NMR (100 MHz, CDCl ):  = 189.8, 149.2, 145.1, 144.3, 141.3,
3
Yield: 90% (64.3 mg); yellow oil.
1
1
38.0, 135.9, 133.3, 131.5, 129.6, 129.5, 125.5, 125.1, 123.2, 120.8,
15.9, 89.3.
©
2020. Thieme. All rights reserved. Synthesis 2021, 53, A–I

G
Synthesis
J.-J. Ji et al.
Paper
1
HRMS (ESI): m/z [M + H]+ calcd for C18H18N O : 308.1394; found:
H NMR (400 MHz, CDCl ):  = 8.49–8.29 (m, 1 H), 8.07 (s, 1 H), 7.93–
3
3
2
7.78 (m, 3 H), 7.50–7.35 (m, 2 H), 7.06 (t, J = 8.4 Hz, 2 H), 6.98 (d, J =
308.1391.
8.0 Hz, 2 H), 6.85 (d, J = 8.4 Hz, 2 H), 2.21 (s, 3 H).
1
3
C NMR (100 MHz, CDCl ):  = 189.1, 167.0 (d, J = 260.9 Hz), 148.0,
2-(5,6-Dimethyl-1H-benzo[d]imidazol-1-yl)-1-phenyl-2-
(p-tolylimino)ethan-1-one (3ab)
3
1
44.3, 142.7, 141.3, 135.1, 132.5 (d, J = 10.1 Hz), 131.6, 129.9 (d, J = 2.6
Hz), 129.7, 125.4, 124.9, 121.1, 120.7, 116.8 (d, J = 22.4 Hz), 115.8,
0.8.
HRMS (ESI): m/z [M + H]+ calcd for C22H17FN O: 358.1350; found:
Yield: 77% (56.5 mg); yellow solid; mp 122.2–123.9 °C.
2
1
H NMR (400 MHz, CDCl ):  = 8.22 (s, 1 H), 7.91 (s, 1 H), 7.82 (d, J =
3
3
8.0 Hz, 2 H), 7.63–7.50 (m, 2 H), 7.38 (t, J = 7.6 Hz, 2 H), 6.97 (d, J = 8.0
Hz, 2 H), 6.86 (d, J = 8.0 Hz, 2 H), 2.41 (d, J = 4.8 Hz, 6 H), 2.20 (s, 3 H).
358.1353.
1
3
C NMR (100 MHz, CDCl ):  = 190.7, 148.6, 143.0, 142.8, 140.7,
3
2
-(1H-Benzo[d]imidazol-1-yl)-1-(3-methoxyphenyl)-2-(p-tolyl-
1
1
35.4, 134.7, 134.6, 133.9, 133.6, 130.0, 129.6, 129.6, 129.2, 121.2,
20.6, 116.1, 20.8, 20.6, 20.3.
imino)ethan-1-one (3na)
Yield: 97% (71.6 mg); yellow solid; mp 120.9–122.3 °C.
HRMS (ESI): m/z [M + H]+ calcd for C24H22N O: 368.1757; found:
368.1757.
3
1
H NMR (400 MHz, CDCl ):  = 8.45–8.35 (m, 1 H), 8.05 (s, 1 H), 7.90–
3
7
8
.79 (m, 1 H), 7.48–7.35 (m, 4 H), 7.29 (d, J = 8.0 Hz, 1 H), 7.10 (dd, J =
.4, 1.6 Hz, 1 H), 6.99 (d, J = 8.0 Hz, 2 H), 6.87 (d, J = 8.0 Hz, 2 H), 3.79
2
-(6-Methyl-1H-benzo[d]imidazol-1-yl)-1-phenyl-2-(p-tolylimi-
(
1
s, 3 H), 2.22 (s, 3 H).
no)ethan-1-one(3ac) and 2-(5-Methyl-1H-benzo[d]imidazol-1-yl)-
1-phenyl-2-(p-tolylimino)ethan-1-one (3ac′)
3
C NMR (100 MHz, CDCl ):  = 190.5, 160.2, 148.3, 144.3, 142.8,
3
1
1
41.4, 134.9, 134.7, 131.6, 130.3, 129.6, 125.3, 124.8, 122.9, 122.5,
21.2, 120.6, 115.9, 112.7, 55.5, 20.8.
Yield: 86% (60.7 mg); yellow oil.
1
H NMR (400 MHz, CDCl ):  = 8.27 (d, J = 7.2 Hz, 2 H), 7.98 (d, J =22.0
3
HRMS (ESI): m/z [M + H]+ calcd for C23H20N O : 370.1550; found:
3
2
Hz, 2 H), 7.82 (d, J = 8.0 Hz, 4 H), 7.71 (d, J = 8.0 Hz, 1 H), 7.63 (s, 1 H),
7.55 (t, J = 7.2 Hz, 2 H), 7.38 (t, J = 7.2 Hz, 4 H), 7.24 (d, J = 9.6 Hz, 2 H),
370.1554.
6
.96 (dd, J = 8.0, 4.4 Hz, 4 H), 6.86 (dd, J = 7.6, 4.4 Hz, 2 H), 2.51 (d, J =
1
-([1,1′-Biphenyl]-4-yl)-2-(1H-benzo[d]imidazol-1-yl)-2-
6.8 Hz, 6 H), 2.19 (s, 6 H).
(
p-tolylimino)ethan-1-one (3oa)
13
C NMR (100 MHz, CDCl ):  = 190.7, 190.6, 148.7, 148.4, 144.6,
3
Yield: 95% (78.9 mg); yellow oil.
142.9, 142.4, 141.4, 140.9, 135.6, 135.5, 134.8, 133.5, 131.8, 129.6,
129.6, 129.3, 126.6, 126.3, 121.2, 120.5, 120.0, 116.0, 115.4, 22.0, 21.6,
1
H NMR (400 MHz, CDCl ):  = 8.50–8.34 (m, 1 H), 8.10 (s, 1 H), 7.97–
3
2
0.8.
7
7
.78 (m, 3 H), 7.59 (d, J = 8.4 Hz, 2 H), 7.53 (d, J = 7.2 Hz, 2 H), 7.45–
.32 (m, 5 H), 6.98 (d, J = 8.4 Hz, 2 H), 6.91 (d, J = 8.0 Hz, 2 H), 2.18 (s, 3
HRMS (ESI): m/z [M + H]+ calcd for C23H19N O: 354.1601; found:
3
H).
354.1602.
1
3
C NMR (100 MHz, CDCl ):  = 190.2, 148.5, 148.2, 144.4, 142.8,
3
1
1
41.5, 139.0, 135.0, 132.1, 131.7, 130.3, 129.7, 129.1, 128.9, 127.9,
27.3, 125.3, 124.9, 121.3, 120.6, 116.0, 20.9.
2-(6-Methoxy-1H-benzo[d]imidazol-1-yl)-1-phenyl-2-(p-tolylimi-
no)ethan-1-one(3ad) and 2-(5-Methoxy-1H-benzo[d]imidazol-1-
yl)-1-phenyl-2-(p-tolylimino)ethan-1-one (3ad′)
HRMS (ESI): m/z [M + H]+ calcd for C28H22N O: 416.1757; found:
3
Yield: 90% (66.4 mg); yellow oil.
416.1752.
1
H NMR (400 MHz, CDCl ):  = 8.33 (d, J = 9.2 Hz, 1 H), 8.06–7.96 (m, 2
3
2
-(1H-Benzo[d]imidazol-1-yl)-1-(naphthalen-2-yl)-2-(p-tolyl-
H), 7.91 (s, 1 H), 7.83 (d, J = 7.6 Hz, 4 H), 7.71 (d, J = 8.8 Hz, 1 H), 7.56
(t, J = 7.4 Hz, 2 H), 7.39 (td, J = 7.6, 2.4 Hz, 4 H), 7.32 (d, J = 2.4 Hz, 1 H),
imino)ethan-1-one (3pa)
7
.09–7.00 (m, 2 H), 6.96 (t, J = 6.6 Hz, 4 H), 6.86 (dd, J = 8.0, 5.2 Hz, 4
Yield: 98% (76.3 mg); yellow solid; mp 144.8–145.9 °C.
H), 3.88 (d, J = 6.4 Hz, 6 H), 2.19 (d, J = 2.8 Hz, 6 H).
1
H NMR (400 MHz, CDCl ):  = 8.48–8.41 (m, 1 H), 8.33 (s, 1 H), 8.13
3
1
3
C NMR (100 MHz, CDCl ):  = 190.7, 190.6, 158.2, 157.7, 148.7,
(s, 1 H), 8.00–7.73 (m, 5 H), 7.60 (t, J = 7.4 Hz, 1 H), 7.51 (t, J = 7.6 Hz, 1
3
1
1
1
48.2, 145.3, 142.9, 142.8, 141.8, 138.5, 135.5, 135.5, 134.9, 134.8,
33.5, 133.5, 132.4, 129.6, 129.6, 129.3, 129.3, 126.0, 121.2, 120.9,
16.5, 114.5, 113.8, 103.1, 100.0, 55.9, 55.8, 20.8.
H), 7.47–7.37 (m, 2 H), 6.92 (s, 4 H), 2.12 (s, 3 H).
1
3
C NMR (100 MHz, CDCl ):  = 190.6, 148.5, 144.4, 142.9, 141.5,
3
1
1
36.6, 134.9, 133.3, 132.3, 131.7, 130.8, 130.0, 129.7, 129.6, 128.0,
27.4, 125.3, 124.9, 123.3, 121.2, 120.6, 116.0, 20.8.
HRMS (ESI): m/z [M + H]+ calcd for C23H20N O : 370.1550; found:
3
3
2
70.1545.
HRMS (ESI): m/z [M + H]+ calcd for C26H20N O: 390.1601; found:
3
390.1598.
2
-(6-Chloro-1H-benzo[d]imidazol-1-yl)-1-phenyl-2-(p-tolylimi-
no)ethan-1-one (3ae) and 2-(5-Chloro-1H-benzo[d]imidazol-1-
yl)-1-phenyl-2-(p-tolylimino)ethan-1-one (3ae′)
Ethyl 2-(1H-Benzo[d]imidazol-1-yl)-2-(p-tolylimino)acetate (3qa)
Yield: 35% (21.5 mg); yellow oil.
Yield: 97% (72.4 mg); yellow oil.
1
H NMR (500 MHz, CDCl ):  = 8.37–8.29 (m, 1 H), 8.24 (s, 1 H), 7.92–
1
3
H NMR (400 MHz, CDCl ):  = 8.55 (d, J = 2.0 Hz, 1 H), 8.38 (d, J = 8.4
3
7
8
.77 (m, 1 H), 7.47–7.38 (m, 2 H), 7.17 (d, J = 8.0 Hz, 2 H), 6.91 (d, J =
.5 Hz, 2 H), 4.25 (q, J = 7.5 Hz, 2 H), 2.36 (s, 3 H), 1.07 (t, J = 7.0 Hz, 3
Hz, 1 H), 8.02 (d, J = 22.4 Hz, 2 H), 7.84–7.79 (m, 5 H), 7.74 (d, J = 8.4
Hz, 1 H), 7.56 (t, J = 7.4 Hz, 2 H), 7.42–7.34 (m, 6 H), 6.97 (dd, J = 8.0,
H).
2
.4 Hz, 4 H), 6.86 (dd, J = 8.4, 4.8 Hz, 4 H), 2.19 (s, 6 H).
1
3
C NMR (125 MHz, CDCl ):  = 160.0, 144.3, 144.0, 143.5, 141.4,
3
135.0, 131.6, 129.7, 125.3, 124.9, 120.6, 120.1, 115.6, 63.1, 21.0, 13.6.
©
2020. Thieme. All rights reserved. Synthesis 2021, 53, A–I

H
Synthesis
J.-J. Ji et al.
Paper
1
3
C NMR (100 MHz, CDCl ):  = 190.5, 190.4, 148.1, 148.0, 145.1,
1-Phenyl-2-(1H-pyrazol-1-yl)-2-(p-tolylimino)ethan-1-one (3aj)
3
1
1
1
42.8, 142.5, 142.5, 142.5, 141.9, 135.7, 135.2, 133.3, 133.2, 132.2,
31.2, 130.4, 130.2, 129.7, 129.6, 129.3, 125.7, 125.5, 121.3, 121.2,
21.2, 120.5, 116.8, 116.4, 20.8.
Yield: 94% (54.4 mg); yellow oil.
1
H NMR (400 MHz, CDCl ):  = 8.48 (d, J = 2.4 Hz, 1 H), 7.80 (d, J = 7.2
3
Hz, 2 H), 7.66 (s, 1 H), 7.50 (t, J = 7.6 Hz, 1 H), 7.37 (t, J = 7.8 Hz, 2 H),
6.95 (d, J = 8.0 Hz, 2 H), 6.86 (d, J = 8.0 Hz, 2 H), 6.49 (dd, J = 2.8, 1.6 Hz,
HRMS (ESI): m/z [M + H]+ calcd for C22H17ClN O: 374.1055; found:
3
374.1056.
1
H), 2.18 (s, 3 H).
1
3
C NMR (100 MHz, CDCl ):  = 190.0, 149.7, 143.6, 142.5, 134.8,
3
2
-(6-Bromo-1H-benzo[d]imidazol-1-yl)-1-phenyl-2-(p-tolylimino)-
1
34.6, 134.4, 129.5, 129.3, 128.9, 127.3, 121.2, 108.8, 20.8.
ethan-1-one (3af) and 2-(5-Bromo-1H-benzo[d]imidazol-1-yl)-1-
phenyl-2-(p-tolylimino)ethan-1-one (3af′)
HRMS (ESI): m/z [M + H]+ calcd for C18H16N O: 290.1288; found:
2
3
90.1286.
Yield: 95% (79.2 mg); yellow oil.
1
H NMR (400 MHz, CDCl ):  = 8.72 (d, J = 1.6 Hz, 1 H), 8.33 (d, J = 8.8
3
1-Phenyl-2-(p-tolylimino)-2-(1H-1,2,4-triazol-1-yl)ethan-1-one
3ak)
Hz, 1 H), 8.03 (s, 1 H), 7.99–7.96 (m, 2 H), 7.81 (d, J = 7.6 Hz, 4 H), 7.69
(
(d, J = 8.4 Hz, 1 H), 7.61–7.48 (m, 4 H), 7.39 (t, J = 7.6 Hz, 4 H), 6.97 (dd,
Yield: 42% (24.4 mg); yellow sticky oil.
J = 8.0, 3.2 Hz, 4 H), 6.86 (dd, J = 8.0, 5.2 Hz, 4 H), 2.19 (d, J = 1.3 Hz, 6
H).
1
H NMR (400 MHz, CDCl ):  = 9.14 (s, 1 H), 8.02 (s, 1 H), 7.82–7.79
3
(
m, 2 H), 7.56 (t, J = 7.4 Hz, 1 H), 7.42 (t, J = 7.8 Hz, 2 H), 7.00 (d, J = 8.0
1
3
C NMR (100 MHz, CDCl ):  = 190.5, 190.4, 148.1, 148.0, 145.5,
3
Hz, 2 H), 6.91 (d, J = 8.4 Hz, 2 H), 2.23 (s, 3 H).
1
1
1
43.2, 142.5, 142.5, 142.4, 141.8, 135.7, 135.2, 133.3, 133.2, 132.5,
30.6, 129.7, 129.6, 129.3, 128.4, 128.3, 123.5, 121.7, 121.2, 121.2,
19.3, 118.8, 117.9, 117.2, 20.8.
1
3
C NMR (100 MHz, CDCl ):  = 188.53, 153.24, 146.94, 142.23,
3
1
41.47, 136.10, 135.11, 133.55, 129.75, 129.40, 129.16, 121.32, 20.89.
HRMS (ESI): m/z [M + H]+ calcd for C17H15N O: 291.1240; found:
HRMS (ESI): m/z [M + H]+ calcd for C22H17BrN O: 418.0550; found:
4
4
3
2
91.1245.
18.055.
2
-Morpholino-1-phenyl-2-(p-tolylimino)ethan-1-one (3al)11c
2
1
-(2-Methyl-1H-imidazol-1-yl)-1-phenyl-2-(p-tolylimino)ethan-
-one (3ag)
Yield: 53% (32.7 mg); light-yellow solid; mp 120.1–121.5 °C.
1
Yield: 71% (43.0 mg); yellow oil.
H NMR (400 MHz, CDCl ):  = 8.48 (d, J = 2.4 Hz, 1 H), 7.80 (d, J = 7.2
3
1
Hz, 2 H), 7.66 (s, 1 H), 7.50 (t, J = 7.6 Hz, 1 H), 7.37 (t, J = 7.8 Hz, 2 H),
H NMR (400 MHz, CDCl ):  = 7.77 (d, J = 7.5 Hz, 2 H), 7.55 (d, J = 7.4
3
6
1
.95 (d, J = 8.0 Hz, 2 H), 6.86 (d, J = 8.0 Hz, 2 H), 6.49 (dd, J = 2.8, 1.6 Hz,
H), 2.18 (s, 3 H).
Hz, 1 H), 7.40 (t, J = 7.7 Hz, 2 H), 7.08 (d, J = 1.1 Hz, 1 H), 6.94 (d, J = 6.9
Hz, 3 H), 6.77 (d, J = 8.2 Hz, 2 H), 2.70 (s, 3 H), 2.18 (s, 3 H).
1
3
1
3
C NMR (100 MHz, CDCl ):  = 194.4, 156.2, 145.4, 134.6, 131.8,
C NMR (100 MHz, CDCl ):  = 190.5, 148.6, 146.6, 142.6, 135.3,
3
3
1
29.7, 129.3, 129.1, 128.9, 122.0, 77.4, 77.1, 76.7, 66.59, 45.4, 20.7.
1
35.0, 133.4, 129.5, 129.4, 129.2, 128.2, 120.8, 117.9, 20.8, 17.3.
HRMS (ESI): m/z [M + H]+ calcd for C19H21N O : 309.1598; found:
HRMS (ESI): m/z [M + H]+ calcd for C19H18N O: 304.1444; found:
3
2
2
3
3
09.1597.
04.1442.
2
1
-(4-Methyl-1H-imidazol-1-yl)-1-phenyl-2-(p-tolylimino)ethan-
-one (3ah)
Funding Information
Yield: 63% (38.2 mg); yellow oil.
We are grateful to the National Natural Science Foundation of China
(11765002 and 21966003), the Science Foundation for Excellent
Young Scholars of Jiangxi Province (20202ZDB01003), the Key Project
of Jiangxi Natural Science Foundation (20192ACB21001), the Postdoc-
toral Science Foundation of Jiangxi Province (2019KY40 and
2019KY41), the Opening Project of Jiangxi Province Key Laboratory of
Polymer Micro/Nano Manufacturing and Devices, and the Innovation
Fund Designated for Graduate Students of East China University of
1
H NMR (400 MHz, CDCl ):  = 7.86 (s, 1 H), 7.77 (dd, J = 8.0, 0.8 Hz, 2
3
H), 7.55 (t, J = 7.4 Hz, 1 H), 7.39 (t, J = 7.8 Hz, 2 H), 7.28 (s, 1 H), 6.93 (d,
J = 8.4 Hz, 2 H), 6.79 (d, J = 8.0 Hz, 2 H), 2.26 (s, 3 H), 2.17 (s, 3 H).
1
3
C NMR (100 MHz, CDCl ):  = 190.8, 147.0, 142.5, 140.3, 135.5,
3
135.4, 135.1, 133.3, 129.6, 129.5, 129.2, 121.1, 112.5, 20.8, 13.6.
HRMS (ESI): m/z [M + H]+ calcd for C19H18N O: 304.1444; found:
3
304.1442.
Technology (DHYC-201913) for financial support.Natio
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-(4-Iodo-1H-imidazol-1-yl)-1-phenyl-2-(p-tolylimino)ethan-1-
one (3ai)
Supporting Information
Yield: 43% (35.7 mg); yellow solid; mp 109.6–111.3 °C.
1
Supporting information for this article is available online at
H NMR (400 MHz, CDCl ):  = 7.84 (s, 1 H), 7.77–7.75 (m, 2 H), 7.70
3
https://doi.org/10.1055/a-1331-7285. Su
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Su
p
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orting Inform atio
n
(s, 1 H), 7.58 (t, J = 7.6 Hz, 2 H), 7.40 (t, J = 8.0 Hz, 2 H), 6.95 (d, J = 8.0
Hz, 2 H), 6.80 (d, J = 8.4 Hz, 2 H), 2.19 (s, 3 H).
1
3
C NMR (100 MHz, CDCl ):  = 190.2, 145.3, 141.8, 137.2, 135.8,
3
References
1
35.7, 132.9, 129.7, 129.6, 129.3, 122.0, 121.1, 85.2, 20.8.
HRMS (ESI): m/z [M + H]+ calcd for C18H15IN O: 416.0254; found:
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