Synthesis of hybrid perillyl-4H-pyrans. Cytotoxicity evaluation against hepatocellular carcinoma HepG2/C3A cell line

Article abstract of DOI:10.1002/jhet.3977

A series of 15 new hybrid perillyl-4H-pyrans compounds was straightforwardly synthesized by a strategy combining the multicomponent reaction and the copper-catalyzed alkyne-azide cycloaddition (CuAAC). The 2-amino-4H-pyrans-3-carbonitrile containing the a

Full text of DOI:10.1002/jhet.3977

Received: 22 January 2020
DOI: 10.1002/jhet.3977
Revised: 4 March 2020
Accepted: 12 March 2020
A R T I C L E
Synthesis of hybrid perillyl-4H-pyrans. Cytotoxicity
evaluation against hepatocellular carcinoma HepG2/C3A
cell line
Ingrid M. Paczkowski1 | Esthéfani P. Guedes1 | Eduardo B. Mass1
Eliana W. de Meneses2 | Lilian A. Marques3 | Mário S. Mantovani3
Dennis Russowsky1
|
|
1Laboratório de Sínteses Orgânicas, Instituto de Química, Departamento de Química Orgânica, Universidade Federal do Rio Grande do Sul,
Porto Alegre, Brazil
2Laboratório de Sólidos & Superfícies, Instituto de Química, Departamento de Química Inorgânica, Universidade Federal do Rio Grande do Sul,
Porto Alegre, Brazil
3Laboratório de Genética Toxicológica, Centro de Ciências Biológicas, Departamento de Biologia Geral, Universidade Estadual de Londrina,
Rodovia Celso Garcia, Londrina, Brazil
Correspondence
Dennis Russowsky, Laboratório de
Abstract
Sínteses Orgânicas, Departamento de
Química Orgânica, Instituto de Química,
Universidade Federal do Rio Grande do
Sul, Av. Bento Gonçalves 9500, CEP
91501-970, Porto Alegre, RS, Brazil.
Email: dennis@iq.ufrgs.br
A series of 15 new hybrid perillyl-4H-pyrans compounds was straightforwardly
synthesized by a strategy combining the multicomponent reaction and the
copper-catalyzed alkyne-azide cycloaddition (CuAAC). The 2-amino-4H-
pyrans-3-carbonitrile containing the alkyne moiety was prepared via mul-
ticomponent reaction between 1,3-dicarbonyl, a propargyloxy aromatic alde-
hyde and malononitrile or ethyl α-cyanoacetate. The alkyne derivative was
sequentially reacted with the perillyl azide component through the copper-
catalyzed [3+2] Huisgen cycloaddition reaction. The antiproliferative activity
of hybrid compounds were evaluated against the human hepatoma HepG2/
C3A cell line.
Funding information
~
Coordenaçao para o Aperfeiçoamento de
Pessoal de Nível Superior (CAPES);
Conselho Nacional de Pesquisas
Científicas e Tecnológicas (CNPq), Grant/
~
Award Number: 309844/2017-7; Fundaçao
de Amparo à Pesquisa do Estado do Rio
Grande do Sul
1 | INTRODUCTION
inefficient due to the inability of drug to act in different
sites of the organism.[2] Alternatively, the use of cocktails
The modern pharmaceutical industry has faced unprece-
dented challenges regarding the development of new
drugs. Although investments have increased steadily over
the past 20 years, new drug approvals have declined by
about 50% over the same period. Considering that many
human diseases involve multiple factors, the decline in
the development of new drugs can be attributed, in part,
to the “one-drug-one-target paradigm,” which is the
development of specific drugs for specific molecular tar-
gets.[1] Moreover, many traditional treatments of multi-
factorial diseases using a single drug have been proved
of drugs represents a breakthrough. However, several
drawbacks associated with severe side effects or low
patient compliance prevent its indiscriminate use.[3] In
order to overcome this problem, a new concept for drugs
has been postulated: “a single chemical entity able to act
on
various
targets
simultaneously.”[4,5]
These
multifunctional compounds (MFCs) have brought prom-
ising results as synergistic effects and minimization of
side effects on therapeutics.[6]
One of the ways to achieve compounds with these
special properties is the “molecular hybridization” in
J Heterocyclic Chem. 2020;1–18.
wileyonlinelibrary.com/journal/jhet
© 2020 Wiley Periodicals LLC
1

2
PACZKOWSKI ET AL.
which two active compounds are connected through a
linker.[7,8] The MFCs are classified as “hybrid drugs”
when two or more molecules, with different activities,
are linked through a stable or metabolizable linker,
where the original molecules remain essentially
unaltered. On the other hand, “chimeric drugs” are
designed when only parts of the original molecules are
choice of perillyl alcohol was due their interesting biolog-
ical activity. Recent studies revealed a promising antican-
cer activity,[25] preventing skin melanoma[26] or anti-
metastatic agent in brain gliomas.[27] Additionally, their
obtention from a natural source turns itself as a compo-
nent from a renewable font.
The chosen method to connect both molecules was
planned by the creation of a stable triazolyl linker via
“Click” reaction.[28] The copper-catalyzed azide-alkyne
cycloaddition (CuAAC, copper catalyzed Huisgen reac-
tion) is a main method to construct the triazolyl
linker.[29,30] This methodology was elegantly demon-
strated by Pal and coworkers synthesizing a plethora of
different complex molecules with interesting biological
activities.[31–33]
The sequential combining of multicomponent and
other reactions, such as CuAAC reactions, has also proven
to be an efficient and versatile strategy to prepare complex
hybrid molecules[34,35] as was demonstrated in a recent
review article.[36] In a previous report, we have applied this
approach successfully in the synthesis of perillyl-
dihydropyrimidinones hybrids as a potent antiproliferative
compounds against cancer cell lines.[37] Thus, a series of
perillyl-4H-pyran hybrids were synthesized combining
multicomponent synthesis of 4-arylpropargyloxy-4H-pyrans
followed by a copper-catalyzed Huisgen reaction with an
azido derivative (Figure 2).
chemically connected forming
(Figure 1).[9,10]
a
new molecule
The multicomponent reactions (MCRs) have emerged as
a powerful tool addressed to discovery of new drugs. The
MCRs are a special kind of one-pot reactions allowing the
formation of several chemical bonds from consecutive and
ordered events of a single process, where three or more
reagents are mixed concomitantly in the same reaction flask.
It occurs with high atom economy, since collateral products
are not formed, and the final product contains all or almost
all the atoms of the starting reagents.[11] Through this strat-
egy, molecules with a high degree of complexity could be
prepared in a direct way without the tedious processes of
isolation and the purification of intermediates.[12] As a supe-
rior synthetic strategy, it brings advantages such as opera-
tional simplicity, functional and structural diversity and
atom efficiency, among others.[13,14] Particularly, the MCRs
have been successfully applied in the synthesis of heterocy-
clic compounds allowing an elegant and rapid synthesis of
polyfunctionalized structurally complex heterocycles.[15]
Among the heterocycles, the synthesis of 4H-pyrans
have attracted great interest because they constitute the
central unit in many natural products. Furthermore, a
variety of pharmacological properties such as: antispas-
modic activity,[16] anticoagulants,[17] antirheumatic,[18]
enhancers in treatment of neurodegenerative diseases,[19]
excitatory amino acid transporters (EAAT)[20] or AIDS-
Associated Dementia[21] have been reported in the
literature. Additionally, 4H-pyrans derivatives were
identified as apoptotic inducers or anticancer active
compounds.[22–24]
2 | RESULTS AND DISCUSSION
2.1 | Synthesis
The multicomponent approach to prepare the 4-aryl-4H-
pyrans was extensively discussed in the literature a pleth-
ora of catalysts and reaction conditions. Homogeneous
Bronsted base catalysts,[38] Lewis acid,[39] ionic liquids[40]
or ammonia[41] are some of them. Heterogeneous cataly-
sis was successfully applied such as heteropoly acids,[42]
MgO,[43] metal/silica nanocomposites[44] and silica/mag-
netic nanoparticle.[45]
Based on this information, we envisioned the prepa-
ration of hybrid pyran compounds starting from
2-amino-3-cyano-4H-pyrans and perillyl alcohol. The
Several reports have discussed the use of ammonium
acetate as catalyst in the multicomponent synthesis of
4-aryl-4H-pyrans and their derivatives.[46,47] Despite pro-
miscuous use of ammonium acetate in organic synthesis,
recently, the ammonium carbonate has been used as
reagent or catalyst in the synthesis of heterocyclic com-
pounds such as Paal-Knorr pyrrole synthesis and
Bucherer-Bergs hydantoin synthesis. In early work, we
observed a superior reactivity of ammonium carbonate in
the multicomponent synthesis of γ-nitroamides or
Hantzsch dihydropyridines, instead ammonium acetate
or ammonium formate.[48] This has encouraged us to
FIGURE 1 Pictorial representation of the hybrid drugs and
chimeric drugs

PACZKOWSKI ET AL.
3
FIGURE 2 General strategy for synthesis
the hybrid compounds
ammonium carbonate catalysis. In all cases, good yields
(85%-94%) were observed (Entries 5-13). The hetero-
aromatic aldehydes such as 2-thiophenecarboxaldehyde
(2l), 2-furancarboxaldehyde (2m) were equally effective
to afford the respective substituted 4-aryl-4H-pyrans
(Entries 14 and 15, respectively). On the other hand, the
use of aliphatic aldehydes 2n–q, showed low yields
(Entries 16-19) in the formation of compounds 5n-q,
respectively. These results were understood by the fact
the aliphatic aldehydes are more reactive than the aro-
matic ones, and the occurrence of side reactions could
be favored. The catalyst 4a was also able to promote the
reaction of dimedone (1a), benzaldehyde (2a) and ethyl
α-cyanoester 3b to afford the respective 4-aryl-4H-pyran
5r in 80% yield (Entry 20).
R1
2a-q
Ammonium
Carbonate
O
R1
O
O
H
O
R3
4a
+
CN
EtOH, r.t., 2h
R
R
NH2
R
R
O
R2
5a-s
3a,b
1a,b
SCHEME 1 Synthesis of 4-aryl-4H-pyran derivatives 5a–r
investigate the use of ammonium carbonate, as catalyst,
to promote the synthesis of 4-aryl-4H-pyran derivatives.
Thus, we carried out the reaction between the 1,3
diketones 1a,b, aldehydes 2a-q and malononitrile 3a or
the ethyl α-cyanoester 3b under catalysis of ammonium
carbonate [(NH4)2CO3, 4a, 20 mol%]. For comparative
purpose, the reactions also were performed in presence of
ammonium formate (NH4HCO2, 4b) and ammonium
acetate (NH4CH3CO2, 4c) in ethanol for 2 hours at room
temperature (Scheme 1). The reaction afforded the
4-aryl-4H-pyrans derivatives 5a-r in good yields. The
results are shown in the Table 1.
2.1.1 | A tentative mechanism
Although complex equilibria and/or competitive reac-
tions may be a part of the mechanisms can occur in a
multicomponent process, simple approximations can be
suggested within certain parameters, allowing a quick
view about the transformations of reagents into prod-
ucts.[51] Several plausible base-catalyzed mechanistic pro-
posals for the multicomponent reaction to access the
2-amino-3-cyano-4H-pyrans derivatives have appeared in
the literature.[50,52] A tentative mechanism starts as an
equilibrium of the ammonium carbonate furnishing the
basic ammonia, responsible to promote the Knoevenagel-
like condensation of the aldehyde 2a and malononitrile
3a, to afford the benzylidene adduct 6. Additionally, the
ammonia induces the formation of enolate 7. A final
event involves the reaction of intermediate 6 and enolate
7 leading to the cyclic intermediate 8, followed by a
hydrogen tropism to afford the 2-amino-3-cyano-4H-
pyran 5a (Scheme 2).
All compounds were easily isolated from washing the
solid product with water and EtOH or, in some cases,
by recrystallization. The compounds were fully
characterised through the usual H NMR, 13C NMR and
1
IR spectroscopic methods, including HRMS for the novel
compounds. The data were in accordance with the pro-
posed structures.
The relative efficiency of different ammonium salts
as catalyst (20 mol%), can be seen comparatively at
entries 1, 2 and 3 in the Table 1. The use of ammonium
carbonate (4a) showed a superior activity, based on the
yield of compound 5a (95%, Entry 3). This higher activ-
ity can be attributed to the fact 1 M equivalent of 4a
releases 2 equivalents of ammonia, which acts as the
base and by decomposition of carbonic acid into CO2.
The ammonium salts 4b or 4c release only 1 M equiva-
lent of ammonia per equivalent of salt and the yield of
reaction decreases (entries 2 and 3, respectively). The
reaction with 1,3-ciclohexanedione (1b) also was effec-
tive for the preparation of 5b (90%; Entry 4). A conjunct
of aromatic 2b-k was reacted with dimedone (1a) and
malononitrile (3a) under the same conditions of
2.1.2 | Synthesis of hybrid molecules
To prepare the hybrid compounds, molecules with an
alkyne portion and other with an azide portion are

4
PACZKOWSKI ET AL.
TABLE 1
Synthesis of 4H-pyrans under ammonium salts catalysis
Carbonyl 1
R
Aldehyde 2
R1
Nitrile 3
Cat.
5a Yield
Refs.
Entry
1
R2
3a
3a
3a
3a
3a
3a
3a
3a
3a
3a
3a
3a
3a
3a
3a
3a
3a
3a
3a
3b
4
(%)
5a
5a
5a
5b
5c
5d
5e
5f
[22]
1a
1a
1a
1b
1a
1a
1a
1a
1a
1a
1a
1a
1a
1a
1a
1a
1a
1a
1a
1a
Me
2a
2a
2a
2a
2b
2c
2d
2f
Ph
CN
CN
CN
CN
CN
CN
CN
CN
CN
CN
CN
CN
CN
CN
CN
CN
CN
CN
CN
CO2Et
4a
4b
4c
4a
4a
4a
4a
4a
4a
4a
4a
4a
4a
4a
4a
4a
4a
4a
4a
4a
95
[23]
2
Me
Me
H
Ph
85
[23]
3
Ph
70
[49]
4
Ph
90
[50]
5
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
4-F C6H4
90
[24]
6
4-Cl C6H4
3,4-(Cl)2 C6H3
4-MeO C6H4
3,4-(MeO)2 C6H3
3,4,5-(MeO) C6H2
3-NO2 C6H4
4-CN C6H4
4-N,N(Me)2C6H4
2-Thiophene
2-Furan
93
[25]
7
91
[23]
8
89
[23]
9
2g
2h
2i
5 g
5h
5i
91
[23]
10
11
12
13
14
15
16
17
18
19
92
[23]
86
[23]
2j
5j
89
[23]
2k
2l
5k
5l
89
[23]
91
[49]
2m
2n
2o
2p
2q
2a
5m
5n
5o
5p
5q
5r
93
[26,27]
CH(CH)3
52
[28]
CH2CH(CH3)2
CH2(CH2)3CH3
CH2(CH2)5CH3
Ph
63
[22]
83
[29]
78
[22]
20
80
1H NMR and 13C NMR as presented in the Data S1.
a
SCHEME 2 A tentative mechanistic pathway to formation of compound 5a
O
O
O
O
O
O
O
OMe
O
H
H
H
H
H
O
O
OMe
9a (95%)
9b (85%)
9c (95%)
9d (97%)
9e (96%)
FIGURE 3 Structures of propargyloxy benzaldehydes 9a–e

PACZKOWSKI ET AL.
5
needed. We choose to have the alkyne portion linked to
the pyran moiety. For this, salicylic aldehyde,
3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, vanillin
and isovanillin were reacted with propargyl bromide to
afford the respective propargyloxy benzaldehydes 9a–e,
respectively, in good yields (Figure 3).
With the propargyl aldehydes 9a–e in hands, a
series of 4-arylpropargyloxy-4H-pyran derivatives 10a–e
was synthesized via multicomponent reaction with
1,3-dikenotes 1a,b, malononitrile 3a or α-cyanoester
3b (Scheme 3). The results are shown in Table 2,
below.
The 4-arylpropargyloxy-4H-pyrans 10a–o were
obtained in good yields. All compounds were fully
characterised by usual 1H NMR, 13C NMR and
I.R. spectroscopic including the HRMS spectrometry for
novel compounds. Next, the azide derivative 14 was pre-
pared starting from the perillyl alcohol (11). The perillyl
alcohol was firstly transformed into perillyl chloride (13)
in presence of carbon tetrachloride (CCl4, 12) through
the Appel reaction in 86% yield after purification.[53] The
compound 13 was converted into perillyl azide (14) in
presence of NaN3 in 84% yield and was used in the crude
form in the next step (Scheme 4).
The next step was the construction of the triazole
linkage between both molecules with alkyne and azide
moieties through the Copper-catalyzed Alkyne-Azide
Cycloaddition (CuAAC, Huisgen reaction). Originally,
the reaction was developed using Cu(I) species as the
active catalyst.[54] After, some expeditious modification
permitted the use of Cu(II) species in presence sodium
ascorbate, as reducing agent, to generate in situ the active
Cu(I) specie.[55] Heterogeneous catalysis, greener process
or ultrasound-promoted reaction also brought technical
improvements performing this methodology.[56–58] Thus,
the 4-arylpropargyloxy-4H-pyrans 10a–o were used as
substrate for the preparation of hybrid compounds by
reaction with perillyl azide (14) under catalysis of
OH
N3
Cl
1. PPh3,
CH2Cl2, -5oC
NaN3
DMF,
r.t., 12 h
84%
2. CCl4,
r.t., 8h
86%
11
13
14
SCHEME 3 Synthesis of 4-arylpropargyloxy-4H-pyran
derivatives 10a–o
SCHEME 4 Preparation of perillyl azide (14) from perillyl
alcohol
TABLE 2
4-arylpropargyloxy-4H-pyran
Synthesis
1
Aldehydes 9
R1
3
Entry
R
R2
R3
OPg
H
R4
3a
3a
3a
3a
3a
3b
3b
3b
3b
3b
3a
3a
3a
3a
3a
10 Yield (%)
derivatives
1
1a
1a
1a
1a
1a
1a
1a
1a
1a
1a
1b
1b
1b
1b
1b
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
H
9c
9b
9a
9d
9e
9c
9b
9a
9d
9e
9c
9b
9a
9d
9e
H
H
CN
10a
90
85
89
88
86
79
82
86
88
81
87
85
85
93
97
2
H
OPg
H
CN
10b
10c
10d
10e
10f
3
OPg
OPg
OMe
H
H
CN
4
OMe
OPg
H
H
CN
5
H
CN
6
OPg
H
CO2Et
CO2Et
CO2Et
CO2Et
CO2Et
CN
7
H
OPg
H
10g
10h
10i
8
OPg
OPg
OMe
H
H
9
OMe
OPg
H
H
10
11
12
13
14
15
H
10j
OPg
H
10k
10l
H
H
OPg
H
CN
H
OPg
OPg
OMe
H
CN
10m
10n
10o
H
OMe
OPg
H
CN
H
H
CN
Abbreviations: Pg, propargyl.

6
PACZKOWSKI ET AL.
CuSO
4
Hybrids
SCHEME 5 Synthesis of perillyl-4H-pyran hybrid compounds 15a–o
TABLE 3
Synthesis of perillyl-4H-pyran hybrids
Entry
Compound
15a
Hybrid structure
Yield (%)
1
81
2
15b
79
3
15c
76
4
15d
82
5
15e
78

PACZKOWSKI ET AL.
7
TABLE 3 (Continued)
Entry
Compound
15f
Hybrid structure
Yield (%)
6
89
7
15g
81
8
15h
77
9
15i
84
10
15j
82
11
15k
80
(Continues)

8
PACZKOWSKI ET AL.
TABLE 3 (Continued)
Entry
Compound
15l
Hybrid structure
Yield (%)
12
72
13
15m
69
14
15n
83
15
15o
76
1
CuSO4/Na-ascorbate system (Scheme 5). The results are
shown in Table 3, below.
through the usual H NMR, 13C NMR, I.R. spectros-
copy including the HRMS analysis of novel com-
pounds. All recorded data was in accordance with the
proposed structures.
The formation of hybrid compounds by the forma-
tion of triazole-link via CuAAC reactions was achieved
in good yields and the relative positions of substituents
on the aromatic ring did not influenced significantly
the yields. The perillyl-4H-pyran hybrids derived from
dimedone component, present different substituents at
C3 position. In the reaction with malononitrile, the
hybrids 15a–e present a cyano-group at this position
Table 3, entries 1-5, respectively). On the other hand,
the reaction with ethyl 2-cyanoacetate afforded an
ethoxy-carbonyl group at C3 position (Entries 6-10,
respectively). The hybrids 15k–o are derived from 1,3-
cyclohexanedione and malononitrile (Entries 11-15,
respectively). All compounds were characterized
2.2 | Biology
2.2.1 | Cytotoxicity against hepatoma
cell line HepG2/C3A
In order to investigate the toxicity of new hybrid com-
pounds, preliminarily, we performed the MTT assay of
compounds 15a–j against the human hepatoma cell line
HepG2/C3A. The human hepatoma cell line HepG2/C3A
is a sub-clone of the hepatoma derived HepG2 cell line

PACZKOWSKI ET AL.
9
TABLE 4
values against the HepG2/C3A cell line
Cell viability percent
Cell viability (%)a
Entry
Hybrid
15a
15b
15c
20 μM
40 μM
60 μM
80 μM
100 μM
1
2
76.0 2.7
90.1 9.6
102.2 2.7
95.9 4.7
92.8 5.1
100.5 4.8b
79.9 5.8
105.6 1.6b
103.3 4.2b
94.4 1.4
61.7 5.2
73.9 5.3
93.8 1.0
97.2 4.2
100.6 8.9
86.3 3.8
77.1.9 7.0
100.9 3.2b
104.0 4.6b
88.2 1.2
55.7 3.1
69.4 4.7
86.9 1.5
92.3 2.4
98.6 8.4
79.4 4.4
82.3 5.6
98.0 4.1
93.0 3.0
80.8 3.7
60.9 5.0
66.6 4.9
91.1 4.5
90.9 4.7
93.1 5.6
68.7 4.7
88.5 4.1
93.1 5.9
88.9 2.2
85.0 3.3
60.8 6.6
71.2 6.1
86.0 1.0
91.3 5.9
88.4 5.5
68.5 3.3
98.4 4.0c
90.3 4.8
95.3 4.9c
79.2 1.7
3
4
15d
15e
15f
5
6
7
15g
15h
15i
8
9
10
15j
aCV (%) of camptothecin 29.7 1.2 (2 μM) as the control.
bNot active.
cDiscrepant data due to the formation of crystals.
FIGURE 4 Images from optical microscopy of morphological changes of HepG2/C3A cells after 24 hours treatment: A, incubated with
15a (40 μM), B, Incubated with 15f (80 μM), C, incubated with Camptothecin (2 μM). D, Control (HepG2/C3A)
and exhibits phenotypic responses and high sensitivity to
toxic compounds. For this reason, they have been widely
used as in vitro models for the study of hepatocellular
functions, as well as in toxicity studies.
In this work, the cytotoxicity was evaluated by the
MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium
bromide) assay described by Mosmann[59] with little
modifications.
purple color by the mitochondrial enzyme succinate
dehydrogenase. Greater reduction reaction shows great
number of viable cells, thus indicating lower cytotoxicity.
The MTT assay was performed in four replicates. The
cytotoxicity was expressed as cell viability (C.V.) as a
function of different concentrations of 20, 40, 60, 80, and
100 μM. The Table 4 shows the percent cell viability for
the hybrid compounds 15a–j.
The assay was based on the reduction of the yellowish
tetrazolium salt into insoluble formazan crystals of
High values of cell viability were observed for all stud-
ied compounds against the HepG2/C3A cell line. The

10
PACZKOWSKI ET AL.
more active hybrid compounds were 15a (55.7% at
60 μM), 15b (66.6% at 80 μM) and 15f (68.7% at 80 μM
and 68.5% at 100 μM (Table 4, entries 1, 2 and 6, respec-
tively). Some compounds were not active at low concen-
tration (entries 6, 8 and 9, respectively). In two cases, the
formation of small crystals of compounds was observed,
and the C.V. (%) values can be uncorrected due to low
solubility of compounds in the culture medium (entries
7 and 9, respectively).
malononitrile (1 mmol, 0.07 g), aldehyde (1 mmol),
ammonium carbonate (0.2 mmol, 0.02 g) and ethanol
(5 mL). The reaction was stirred for 2-3 hours at room
temperature and was monitored by TLC. After comple-
tion of the reaction, the solvent was evaporated and the
solid obtained was washed with cold ethanol, filtered
and dried in a vacuum pump. The crude products show
a good level of purity, confirmed by the melting point
compared with corresponding literature.
The images from optical microscopy showed the mor-
phological changes of cellular culture after the incuba-
tion of perillyl-4H-pyran hybrids (Figure 4). The
Figure 4A,B show the changes of cell morphology
observed after 24 hours of incubation with compound
15a (40 μM) and 15f (80 μM), respectively. Figure 4C
show the morphology changes after treatment with
Camptothecin (2 mM). The culture of HepG2/C3A cell
line, used as a control, is showed in Figure 4D. The
perillyl-4H-pyran hybrids treatments clearly reduced the
cell confluency and cause apoptosis morphology, as
pyknotic nuclei and membrane breakdown, mainly in
compound 15f as showed in detail in Figure 4B.
4.1.2 | General procedure for synthesis
of the 4H-pyrans 5n–q
To a round-bottom flask equipped with a magnetic stir-
ring bar were added malononitrile (1 mmol, 0.07 g), ali-
phatic aldehyde (1 mmol), ammonium carbonate
(0.2 mmol, 0.02 g) and ethanol (5 mL). The reaction was
stirred for 0.5 hours at room temperature and was moni-
tored by TLC. After forming the intermediate, dimedone
(1 mmol, 0.14 g) was added. The reaction was stirred for
3-4 hours and was monitored by TLC. After completion
of the reaction, the solvent was evaporated and the solid
obtained was washed with cold ethanol, filtered and
dried in a vacuum pump.
3 | CONCLUSION
The synthetic strategy based on the combining mul-
ticomponent reaction and CuAAC has been proved a
powerful tool to prepare structurally complex molecules
in a quick and straightforward way. The use of ammo-
nium carbonate, as an environmental benign catalyst,
proved to be efficient for the preparation of 4H-pyran
derivatives via multicomponent process. Thus, a series of
structurally novel perillyl-4H-pyran hybrid compounds
were synthesized in few steps and good yields. The cyto-
toxicity of hybrid compounds was evaluated against
HepG2/C3a cell line. The morphological changes of
tumoral cells showed the presence of pyknotic nuclei as
evidence of apoptosis process. Unfortunately, a poor cyto-
toxicity was observed against HepG2/C3A cell line. New
investigations with different tumoral cell lines are under
investigations.
4.1.3 | General procedure for synthesis
of the 4H-pyran 5r
To a round-bottom flask equipped with a magnetic stir-
ring bar were added ethyl 2-cyanoacetate (1 mmol,
0.11 g), benzaldehyde (1 mmol, 0.11 g), ammonium car-
bonate (0.2 mmol, 0.02) and ethanol (5 mL). The reaction
was stirred for 1 hour under refluxing ethanol and was
monitored by TLC. After forming the intermediate,
dimedone were added (1 mmol, 0.14 g). The reaction was
stirred for 3-4 hours and was monitored by TLC. After
completion of the reaction, the solvent was evaporated
and the solid obtained was recrystallized from hot etha-
nol. The solid was filtered, washed with cold ethanol,
and dried in a vacuum pump.
4 | EXPERIMENTAL
4.1 | Chemistry
4.1.4 | General procedure for synthesis
4-arylpropargyloxy 4H-pyrans 10a–e,k–o
In a round-bottomed flask were added dimedone
(1 mmol, 0.14 g), malononitrile (1, mmol, 0.07 g), alde-
hyde 1 mmol (9a-d), ammonium carbonate (0.2 mmol,
0.02 g) and 5 mL of ethanol as the solvent. The reaction
was stirred for 3-4 hours, at room temperature, and was
monitored by TLC. After the finish of reaction was, the
4.1.1 | General procedure for the
synthesis of 4H-pyrans 5a–m
To a round-bottom flask equipped with a magnetic stir-
ring bar were added dimedone (1 mmol, 0.14 g),

PACZKOWSKI ET AL.
11
solvent was evaporated in the rotary evaporator, and then
the solid obtained was washed with ethanol, filtered and
dried in a rotary evaporator.
3.53 (t, J = 4.0 Hz, 1H), 3.70 (s, 3H), 4.12 (s, 1H), 4.71 (d,
J = 2.0 Hz, 2H), 6.62-6.65 (m, 1H), 6.70 (d, J = 2.0 Hz,
1H), 6.92 (d, J = 2.0 Hz, 1H), 6.97 (s, 2H). 13C NMR
(DMSO-d6, 100 MHz): δ 27.2, 28.9, 32.2, 35.5, 39.7, 50.4,
55.9, 56.5, 58.9, 78.7, 80.0, 111.6, 113.1, 114.4, 119.3,
120.3, 138.9, 145.7, 149.3, 158.8, 162.9, 196.2. IR (νmax
cm−1): 3349, 3163, 2976, 2192, 1633, 1017. HRMS calc. for
[C22H22N2O4+Na]: 401.1472, found: 401.1473.
2-amino-7,7-dimethyl-5-oxo-4-{4-[(prop-2-yn-1-yl)oxy]
phenyl}-5,6,7,8-tetrahy dro-4H-1-benzopyran-
3-carbonitrile (10a)
1
Yield: 89%, white solid, m.p. 212ꢀC. H NMR (DMSO-d6,
400 MHz): δ 0.95 (s, 3H), 1.03 (s, 3H), 2.10 (d, J = 16.0 Hz,
1H), 2,24 (d, J = 16.0 Hz, 1H), 2.50 (2H), 3.54 (t,
J = 4.0 Hz, 1H), 4.13 (s, 1H), 4.74 (d, J = 4.0 Hz, 2H),
6.89 (d, J = 8.0 Hz, 2H), 6.96 (s, 2H), 7,05 (d, J = 8.0 Hz,
2H). 13C NMR (DMSO-d6, 100 MHz): δ 26.9, 28.3, 31.8,
34.8, 39.7, 50.0, 55.3, 58.5, 78.1, 79.4, 112.9, 114.5, 119.8,
128.2, 137.6, 155.9, 158.4, 162.2, 195.7. IR (νmax cm−1):
3358, 3181, 2957, 2192, 2118, 1642, 1204. HRMS calc. for
[C21H20N2O3+Na]: 371.1366, found: 371.1364.
2-amino-7,7-dimethyl-5-oxo-4-{4-methoxy-3-[(prop-2-yn-
1-yl)oxy]phenyl}-5,6, 7,8-tetrahydro-4H-1-benzopyran-
3-carbonitrile (10e)
Yield: 86%, pale yellow solid, m.p. 187ꢀC-189ꢀC. 1H MNR
(DMSO-d6, 400 MHz): δ 0.98 (s, 3H), 1.04 (s, 3H), 2.11 (d,
J = 16.0 Hz, 1H), 2,25 (d, J = 16.0 Hz, 1H), 2.50 (2H),
3.50 (t, J = 4.0 Hz, 1H), 3.73 (s, 3H), 4,12 (s, 1H), 4.68 (d,
J = 2.0 Hz, 2H), 6.73-6.79 (m, 2H), 6.90 (d, J = 2.0 Hz,
1H), 6.94 (s, 2H). 13C NMR (DMSO-d6, 100 MHz): δ 27.4,
28.8, 32.2, 35.4, 39.7, 50.5, 56.0, 56.9, 58.8, 78.8, 79.6,
112.4, 113.3, 114.2, 120.3, 121,1, 137.6, 146.8, 148.6, 158.9,
162.7, 196.4. IR (νmax cm−1): 3377, 3293, 3181, 2966, 2192,
1652, 1362, 1017. HRMS calc. for [C22H22N2O4+Na]:
401.1472, found: 401.1469.
2-amino-7,7-dimethyl-5-oxo-4-{3-[(prop-2-yn-1-yl)oxy]
phenyl}-5,6,7,8-tetrahy dro-4H-1-benzopyran-
3-carbonitrile (10b)
Yield: 85%, white solid, m.p. 172ꢀC-173ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 0.95 (s, 3H), 1.02 (s, 3H), 2.11 (d,
J = 16.0 Hz, 1H), 2.23 (d, J = 16.0 Hz, 1H), 2.50 (2H), 3.54
(t, J = 4.0 Hz, 1H), 4.13 (s, 1H), 4.72 (d, J = 4.0 Hz, 2H),
6.67-6.82 (m, 3H), 7.00 (s, 2H), 7.21 (t, J = 8.0 Hz, 1H).
13C NMR (DMSO-d6, 100 MHz): δ 26.9, 28.3, 31.8, 35.4,
39.7, 49.9, 55.4, 58.1, 78.2, 79.2, 112.1, 112.5, 114.2, 119.7,
120.1, 129.3, 146.4, 157.3, 158.5, 162.6, 195.8. IR (νmax
cm−1): 3451, 3302, 2948, 2183, 1670, 1362, 1036. HRMS
calc. for [C21H20N2O3+Na]: 371.1366, found: 371.1365.
2-amino-5-oxo-4-[2-(prop-2-yn-1-yloxy)phenyl]-
5,6,7,8-tetrahydro-4H-chromene −3-carbonitrile (10k)
Yield: 83%, white solid, m.p. 193ꢀC-195ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 1.83-1.99 (m, 2H), 2.20-2.34 (m,
2H), 2.53-2.66 (m, 2H), 3.54 (t, J = 2.0 Hz, 1H), 4.14 (s, 1H),
4.74 (d, J = 4.0 Hz, 2H), 6.89 (d, J = 8.0 Hz, 2H), 6.96 (s,
2H), 7.08 (d, J = 8.0 Hz, 2H). 13C MNR (DMSO-d6,
100 MHz): δ 19.8, 26.4, 34.6, 36.3, 55.3, 58.3, 78.1, 79.4,
114.0, 114.6, 119.8, 128.2, 137.7, 155.9, 158.4, 164.2, 195.9, IR
(νmax cm−1): 3452, 3219, 2950, 2193, 2119, 1691, 1205. HRMS
calc. for [C19H16N2O3+Na]: 343.1053, found: 343.1057.
2-amino-7,7-dimethyl-5-oxo-4-{2-[(prop-2-yn-1-yl)oxy]
phenyl}-5,6,7,8-tetrahdro-4H-1-benzopyran-
3-carbonitrile (10c)
Yield: 90%, white solid, m.p. 209ꢀC-210ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 0.97 (s, 3H), 1.04 (s, 3H), 2.06 (d,
J = 16.0 Hz, 1H), 2.24 (d, J = 16.0 Hz, 1H), 2.50 (2H),
3.56 (t, J = 4.0 Hz, 1H), 4.43 (s, 1H), 4.67 4.77 (m, 2H),
6.84 (s, 2H), 6.89 (t, J = 7.0 Hz, 1H), 7.00-7.04 (m, 2H),
7.14-7.19 (m, 1H). 13C NMR (DMSO-d6, 100 MHz): δ
26.9, 28.6, 31,0, 31.8, 39.8, 50.1, 56.1, 57.1, 78.1, 79.4,
111.8, 112.8, 119.9, 121.1, 127.8, 129.2, 132.5, 155.1, 159.0,
163.1, 195.7. IR (νmax cm−1): 3460, 3311, 3256, 3191, 2966,
2973, 2192, 1689, 1381, 1017. HRMS calculated for
[C21H20N2O3+Na]: 371.1366, found: 371.1364.
2-amino-5-oxo-4-[3-(prop-2-yn-1-yloxy)phenyl]-
5,6,7,8-tetrahydro-4H-chromene −3-carbonitrile (10l)
Yield: 85%, White solid, m.p. 207ꢀC-208ꢀC, 1H NMR
(DMSO-d6, 400 MHz): δ 1.84-2.00 (m, 2H), 2.23-2.36 (m,
2H), 2.55-2.68 (m, 2H), 3.55 (t, J = 2.0 Hz, 1H), 4.16 (s,
1H), 4.74 (d, J = 4.0 Hz, 2H), 6.71 (t, J = 2.0 Hz, 1H),
6.77-6.84 (m, 2H), 6.99 (s, 2H), 7.22 (t, J = 8.0 Hz, 1H).
13C NMR (DMSO-d6, 100 MHz): δ 19.8, 26.5, 35.2, 36.3,
55.3, 58.0, 78.2, 79.2, 112.2, 113.6, 114.0, 119.7, 120.1,
129.3, 146.4, 157.3, 158.5, 164.6, 195.8. IR (νmax cm−1):
3340, 3265, 3153, 2192, 1642, 1362, 1036. HRMS calc. for
[C19H16N2O3+Na]: 343.1053, found: 343.1053.
2-amino-7,7-dimethyl-5-oxo-4-{3-methoxy-4-[(prop-2-yn-
1-yl)oxy]phenyl}-5,6, 7,8-tetrahydro-4H-1-benzopyran-
3-carbonitrile (10d)
2-amino-5-oxo-4-[4-(prop-2-yn-1-yloxy)phenyl]-
Yield: 88%, pale yellow solid, m.p. 180ꢀC-182ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 0.97 (s, 3H), 1.03 (s, 3H), 2.11 (d,
J = 16.0 Hz, 1H), 2.25 (d, J = 16.0 Hz, 1H), 2.50 (2H),
5,6,7,8-tetrahydro-4H-chromene −3-carbonitrile (10m)
Yield: 83%, white solid, m.p. 193ꢀC-194ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 1.83-1.99 (m, 2H), 2.20-2.34

12
PACZKOWSKI ET AL.
(m, 2H), 2.53-2.66 (m, 2H), 3.54 (t, J = 2.0 Hz, 1H), 4.14
(s, 1H), 4.74 (d, J = 4.0 Hz, 2H), 6.89 (d, J = 8.0 Hz, 2H),
6.96 (s, 2H), 7.08 (d, J = 8.0 Hz, 2H). 13C NMR (DMSO-
d6, 100 MHz): δ 19.8, 26.4, 34.6, 36.3, 55.3, 58.3, 78.1,
79.4, 114.0, 114.6, 119.8, 128.2, 137.7, 155.9, 158.4, 164.2,
195.9. IR (νmax cm−1): 3452, 3219, 2950, 2193, 2119, 1691,
1205. HRMS calc. for [C19H16N2O3+Na]: 343.1053, found:
343.1057.
ethanol. The solid was filtered, washed with cold ethanol
and dried in a vacuum pump.
Ethyl 2-amino-7,7-dimethyl-5-oxo-4-{4-[(prop-2-yn-1-yl)
oxy]phenyl}-5,6,7,8-te trahydro-4H-1-benzopyran-
3-carboxylate (10f)
Yield: 86%, white solid, m.p. 120ꢀC-121ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 0.90 (s, 3H), 1.03 (s, 3H), 1.10 (t,
J = 8.0 Hz, 3H), 2.06 (d, J = 16.0 Hz, 1H), 2.25 (d,
J = 16.0 Hz, 1H), 2.46 (d, J = 16.0 Hz, 1H), 2.53 (d,
J = 16.0 Hz, 1H), 3.52 (brs, 1H), 3.89-4.01 (m, 2H), 4.46
(s, 1H), 4.70 (d, J = 4.0 Hz, 2H), 6.81 (d, J = 8.0 Hz, 2H),
7.05 (d, J = 8.0 Hz, 2H), 7.53 (s, 2H). 13C NMR (DMSO-
d6, 100 MHz): δ 14.3, 26.6, 28.6, 31.9, 32.4, 39.6, 50.0,
55.3, 58.8, 78.1, 78.1, 79.5, 114.0, 115.7, 128.6, 139.3,
155.3, 159.1, 162.0, 168.1, 195.9. IR (νmax cm−1): 3489,
3248, 2950, 2110, 1691, 1652, 1196. HRMS calc. for
[C23H25N1O5+Na]: 418.1625, found: 418.1625.
2-amino-4-[3-methoxy-4-(prop-2-yn-1-yloxy)phenyl]-
5-oxo-5,6,7,8-tetrahydro-4H-chromene-
3-carbonitrile (10n)
Yield: 93%, pale yellow solid, m.p. 203ꢀC-205ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 1.85-1.99 (m, 2H), 2.24-2.35 (m,
2H), 2.56-2.67 (m, 2H), 3.54 (t, J = 2.0 Hz, 1H), 3.73 (s,
3H), 4.15 (s, 1H), 4.72 (d, J = 2.0 Hz, 2H), 6.64 (dd,
J = 2.0 Hz and J = 6.0 Hz, 1H), 6.75 (d, J = 2.0 Hz, 1H),
6.93 (d, J = 8.0 Hz, 1H), 6.98 (s, 2H). 13C-RMN (DMSO-
d6, 100 MHz): δ 19.8, 26.5, 34.9, 36.4, 55.5, 56.1, 58.3,
78.2, 79.5, 111.4, 113.8, 114.2, 118.7, 119.9, 138.5, 145.2,
148.9, 158.4, 164.4, 195.9. IR (νmax cm−1): 3396, 3311,
3265, 3191, 2929, 2192, 2118, 1652, 1362, 1129. HRMS
calc. for [C20H18N2O4+Na]: 373.1159, found: 373.1160.
Ethyl 2-amino-7,7-dimethyl-5-oxo-4-{3-[(prop-2-yn-1-yl)
oxy]phenyl}-5,6,7,8-te trahydro-4H-1-benzopyran-
3-carboxylate (10g)
Yield: 82%, white solid, m.p. 138ꢀC-140ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 0.91 (s, 3H), 1.03 (s, 3H), 1.11 (t,
J = 8.0 Hz, 3H), 2.07 (d, J = 16.0 Hz, 1H), 2.6 (d,
J = 16.0 Hz, 1H), 2.48 (d, J = 16.0 Hz, 1H), 2.54 (d,
J = 16.0 Hz, 1H), 3.55 (t, J = 2.0 Hz, 1H), 3.089-4.00 (m,
2H), 4.48 (s, 1H), 4.66-4.75 (m, 2H), 6.72-6.76 (m, 3H),
7.14 (t, J = 8.0 Hz, 1H), 7.56 (s, 2H). 13C NMR (DMSO-
d6, 100 MHz): δ 14.3, 26.6, 28.6, 31.9, 33.1, 39.5, 50.0,
55.3, 58.8, 77.6, 78.2, 79.3, 111.5, 114.9, 115.4, 120.6,
128.7, 148.0, 156.9, 159.2, 162.3, 168.0, 195.8. IR (νmax
cm−1): 3498, 3321, 3265, 2957, 2127, 1698, 1362, 1045.
HRMS calc. for [C23H25N1O5+Na]: 418.1625, found:
418.1627.
2-amino-4-[4-methoxy-3-(prop-2-yn-1-yloxy)phenyl]-
5-oxo-5,6,7,8-tetrahydro-4H-chromene-
3-carbonitrile (10o)
Yield: 97%, pale yellow solid, m.p. 181ꢀC-183ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 1.85-2.00 (m, 2H), 2.22-2.35 (m,
2H), 2.54-2.65 (m, 2H), 3.52 (t, J = 2.0 Hz, 1H), 3.73 (s,
3H), 4.13 (s, 1H), 4.69-4.70 (m, 2H), 6.74-6.79 (m, 2H),
6.89 (d, J = 8.0 Hz, 1H), 6.93 (s, 2H). 13C NMR (DMSO-
d6, 100 MHz): δ 19.9, 26.5, 34.8, 36.4, 55.6, 56.3, 58.3,
78.3, 79.2, 112.0, 113.5, 113.9, 119.8, 120.5, 137.2, 146.3,
148.1, 158.5, 164.3, 195.8. IR (νmax cm−1): 3405, 3321,
3256, 3191, 2938, 2826, 2192, 1652, 1372, 1017. HRMS
calc. for [C20H18N2O4+Na]: 373.1159, found: 373.1155.
Ethyl 2-amino-7,7-dimethyl-5-oxo-4-{2-[(prop-2-yn-1-yl)
oxy]phenyl}-5,6,7,8-tetrahydro-4H-1-benzopyran-
3-carboxylate (10h)
4.1.5 | General procedure for synthesis
4-arylpropargyloxy 4H-iyrans 10f–j
Yield: 79%, pale yellow solid, m.p. 160ꢀC-161ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 0.90 (s, 3H), 1.03 (s, 3H), 1.07 (t,
J = 8.0 Hz, 3H), 1.99 (d, J = 16.0 Hz, 1H), 2.22 (d,
J = 16.0 Hz, 1H), 2.41 (d, J = 18.0 Hz, 1H), 2.52 (d,
J = 18.0 Hz, 1H), 3.52 (t, J = 2.0 Hz, 1H), 3.79-3.91 (m,
2H), 4.57 (s, 1H), 4.62-4.71 (m, 2H), 6.80-6.84 (m, 1H),
6.91 (d, J = 8.0 Hz, 1H), 7.06-7.10 (m, 1H), 7.16 (dd,
J = 6.0 Hz and 2.0 Hz, 1H), 7.47 (s, 2H). 13C NMR
(DMSO-d6, 100 MHz): δ 14.2, 26.6, 28.8, 31.3, 31.8, 39.8,
50.2, 55.6, 58.5, 75.9, 77.8, 79.5, 112.2, 113.3, 119.9, 127.1,
131.8, 132.9, 155.6, 159.7, 162.5, 168.4, 195.7. IR (νmax
cm−1): 3377, 3302, 2957, 1689, 1381, 1204, HRMS calc. for
[C23H25N1O5+Na]: 418.1625, found: 418.1623.
In
a round-bottomed flask were added dimedone
(1 mmol, 0.14 g), malononitrile (1, mmol, 0.07 g), alde-
hyde 1 mmol (9a–d), ammonium carbonate (0.2 mmol,
0.02 g) and 5 mL of ethanol as the solvent. The reaction
was stirred for 1 hour under refluxing ethanol and was
monitored by TLC. After forming the intermediate,
dimedone were added (1 mmol, 0.14 g). The reaction was
stirred for 3-4 hours and was monitored by TLC. After
completion of the reaction, the solvent was evaporated
and the solid obtained was recrystallized from hot

PACZKOWSKI ET AL.
13
Ethyl 2-amino-7,7-dimethyl-5-oxo-4-{3-methoxy-
4-[(prop-2-yn-1-yl)oxy]phenyl}-5,6,7,8-tetrahydro-4H-
1-benzopyran-3-carboxylate (10i)
1.96-2.06 (m, 1H), 2.10-2.23 (m, 4H), 3.64 (d, J = 12.0 Hz,
1H), 3.69 (d, J = 12.0 Hz, 1H), 4.76 (d, J = 1 Hz, 1H), 4.75
(t, J = 2.0 Hz, 1H), 5.75 (s, 1H). 13C NMR (CDCl3,
100 MHz): δ 20.7, 27.0, 27.3, 30.4, 40.7, 57.4, 108.8, 126.3,
132.1, 149.3. IR (νmax cm−1): 3085, 2923, 2096, 1645, 1439,
1242, 891.
Yield: 81%, pale yellow solid, m.p. 128ꢀC-130ꢀC. 1H NMR
(DMSO-d6, 400 MHz): δ 0.93 (s, 3H), 1.03 (s, 3H), 1.13 (t,
J = 8.0 Hz, 3H), 2.08 (d, J = 16,0 Hz, 1H), 2.26 (d,
J = 16.0 Hz, 1H), 2.50 (1H), 2,55 (d, J = 18.0 Hz, 1H),
3.51 (t, J = 2.0 Hz, 1H), 3.70 (s, 3H), 3.87-3.99 (m, 2H),
4.46 (s, 1H), 4.68 (d, J = 2.0 Hz, 2H), 6.60 (dd, J = 6.0 and
2.0 Hz, 1H), 6.74 (d, J = 2.0 Hz, 1H), 6.86 (d, J = 8.0 Hz,
1H), 7.52 (s, 2H). 13C NMR (DMSO-d6, 100 MHz): δ 14.3,
26.5, 28.7, 31.9, 32.7, 39.6, 50.0, 55.4, 56.0, 58.8, 78.0, 78.1,
79.5, 112.1, 113.7, 115.6, 119.1, 140.2, 144.7, 148.3, 159.1,
162.2, 168.1, 195.9. IR (νmax cm−1): 3405, 3256, 2948,
2118, 1717, 1512, 1250, 1008. HRMS calc. for
[C24H27N1O6+Na]: 448.1731, found: 448.1731.
4.1.7 | General procedure for the
synthesis of perillyl-4H-pyran hybrids 15a–j
In a round-bottomed flask, were added the propargyloxy
4H-pyran (10a-o, 0.5 mmol), the perillyl azide (14,
0.6 mmol, 0.10 g), dichloromethane (5.0 mL), water
(5.0 mL), copper sulfate pentahydrate (0.05 mmol, 0.02 g)
and sodium ascorbate (0.05 mmol, 0.01 g). The reaction
was kept under stirring at room temperature for 24 hours,
and the end of the reaction was confirmed by TLC. Then,
10 mL of a 0.1 M solution of EDTA was added and the stir
was continued for 10 minutes. The aqueous phase was
extracted with dichloromethane (3 × 10 mL). The organic
phases were combined, washed with saturated NaCl solu-
tion, dried over anhydrous magnesium sulfate and filtered.
The filtrate was reduced under vacuum to give a solid that
was purified by column chromatography using a gradient
of hexane-ethyl acetate as eluent.
Ethyl 2-amino-7,7-dimethyl-5-oxo-4-{4-methoxy-
3-[(prop-2-yn-1-yl)oxy]phenyl} -5,6,7,8-tetrahydro-4H-
1-benzopyran-3-carboxylate (10j)
1
Yield: 88%, Pale yellow solid, m.p. 153ꢀC-155ꢀC. H NMR
(DMSO-d6, 400 MHz): δ 0.92 (s, 3H), 1,04 (s, 3H), 1.13 (t,
J = 8.0 Hz, 3H), 2.07 (d, J = 16.0 Hz, 1H), 2.26 (d,
J = 16.0 Hz, 1H), 2.50 (2H), 3,51 (t, J = 2.0 Hz, 1H), 3.69 (s,
3H), 3.89-4.02 (m, 2H), 4.45 (s, 1H), 4.58-4.69 (m, 2H), 6.71
(dd, J = 6.0 e 2.0 Hz, 1H), 6.81-6.83 (m, 2H), 7.50 (s, 2H).
13C NMR (DMSO-d6, 100 MHz): δ 14.3, 26.7, 28.6, 31.8
32.5, 39.7, 50.0, 55.5, 56.4, 58.8, 78.0, 78.2, 79.3, 111.6, 114.7,
115.7, 120.9, 138.8, 145.8, 147.6, 159.2, 162.1, 168.0, 195.3.
IR (νmax cm−1): 3423, 3302, 2957, 1679, 1362, 1027. HRMS
calc. for [C24H27N1O6+Na]: 448.1731, found: 448.1731.
2-amino-7,7-dimethyl-5-oxo-4-{2-[(1-(S)-perillyl-methyl)-
1H-1,2,3-triazol-4-yl]me thoxyphenyl}-5,6,7,8-tetrahydro-
4H-chromene-3-carbonitrile (15a)
1
Yield: 81%, pale yellow solid, m.p. 91ꢀC-93ꢀC. H NMR
(CDCl3, 400 MHz): δ 1.05 (s, 3H, CH3), 1.09 (s, 3H,
CH3), 1.40-1.47 (m, 1H, perillyl-H), 1.72 (s, 3H,
H2C C CH3), 1.78-1.83 (m, 1H, perillyl-H), 1.93-2.02 (m,
3H, (CH3)2C CH2 + perillyl-H), 2.09-2.12 (m, 2H, perillyl-
H), 2.14-2.19 (m, 2H, perillyl-H), 2.34 (s, 2H, CH2 C O),
4.42 (s, 2H, NH2), 4.69 (s, 1H, C CH C ), 4.72 (d,
J = 12.0 Hz, 2H, C CH2), 4.84 (d, J = 16.0 Hz, 1H,
OCH2 ), 5.22-5.32 (m, 2H, N CH2 C ), 5.75 (s, 1H,
C CH ), 6.88-6.94 (m, 2H, aromatic-H), 7.11-7.18 (m,
2H, aromatic-H), 7.73 (s, 1H, C CH N ). 13C NMR
(CDCl3, 100 MHz): δ 20.7, 26.3, 27.0, 27.6, 28.9, 30.4, 30.7,
32.1, 40.4, 50.6, 56.3, 61.9, 62.2, 77.2, 109.0, 112.2, 112.8,
119.2, 121.1, 123.3, 127.2, 128.3, 129.4, 131.1, 132.0, 144.1,
149.0, 155.5, 158.0, 162.2, 195.9. IR (νmax cm−1): 3433, 2948,
2192, 1689, 1362, 1213. HRMS calc. for [C31H35N5O3+Na]:
548.2632, HRMS found: 548.2625.
4.1.6 | Procedure for the synthesis of (S)-
perillyl azide 14
In a round-bottomed flask containing perillyl chloride
(13, 5.0 mmol) and dimethylformamide (1.5 mL) was
added sodium azide (15.0 mmol) in one portion. The
reaction was stirred for 12 hours, at room temperature,
and the end of the reaction was confirmed by TLC. Then,
water (5.0 mL) was added, and the aqueous phase was
washed with hexane (3 × 15.0 mL) and separated. The
organic phases were combined, washed with saturated
NaCl solution, dried over anhydrous magnesium sulfate,
filtered, and the filtrate was evaporated, yielding the
perillyl azide (14) in 84% and was used in the next step in
the crude form.
2-amino-7,7-dimethyl-5-oxo-4-{3-[(1-(S)-perillyl-methyl)-
1H-1,2,3-triazol-4-yl]me thoxyphenyl}-5,6,7,8-tetrahydro-
4H-chromene-3-carbonitrile (15b)
(4S)-1-(azidomethyl)-4-(prop-1-en-2-yl)cyclohex-
1-ene (14)
Yield: 84%, Colorless liquid. H NMR (CDCl3, 400 MHz):
1
Yield: 79%, pale yellow solid, m.p. 176ꢀC-178ꢀC. 1H NMR
(CDCl3, 400 MHz): δ 1.05 (s, 3H, CH3), 1.11 (s, 3H,
δ 1.47-1.57 (m, 1H), 1.75 (s, 3H), 1.84-1.90 (m, 1H),

14
PACZKOWSKI ET AL.
CH3), 1.41-1.51 (m, 1H, perillyl-H), 1.73 (s, 3H,
6.92 (d, J = 8.0 Hz, 1H, aromatic-H), 7.58 (s, 1H,
C CH N ). 13C RMN (CDCl3, 100 MHz): δ 20.4, 26.0,
26.7, 27.2, 28.6, 30.1, 31.8, 34.7, 40.1, 40.3, 50.3, 55.5, 56.1,
62.8, 62.9, 76.9, 108.6, 111.3, 113.6, 118.5, 118.9, 122.3,
127.1, 131.4, 136.7, 144.2, 146.2, 148.7, 148.9, 157.2, 161.2,
195.2. IR (νmax cm−1): 3331, 3172, 2948, 2183, 1689, 1512,
1362, 1036. HRMS calc. for [C32H37N5O4+Na]: 578.2738,
HRMS found: 578.2741.
H2C C CH3), 1.79-1.84 (m, 1H, perillyl-H), 1.93-2.03
(m, 3H, (CH3)2C CH2 + perillyl-H), 2.11-2.17 (m, 2H
perillyl-H), 2.18-2.27 (m, 2H perillyl-H), 2.41 (d,
J = 18.0 Hz, 1H, CH2 C O), 2.51 (d, J = 18.0 Hz, 1H,
CH2 C O), 4.38 (s, 1H, C CH C ), 4.62 (brs,
NH2), 4.72 (d, J = 16.0 Hz, 2H, C CH2), 4.85 (s, 2H,
OCH2 ), 5.20 (s, 2H, N CH2 C ), 5.77 (s, 1H,
C CH ), 6.81-6.88 (m, 3H, aromatic-H), 7.21 (t,
J = 8.0 Hz, 1H, aromatic-H), 7.60 (s, 1H, C CH N ).
13C NMR (CDCl3, 100 MHz): δ 20.7, 26.3, 27.1, 27.9, 28.6,
30.4, 32.2, 35.4, 40.4, 40.6, 50.6, 56.5, 62.0, 63.1, 77.2,
109.0, 113.4, 113.7, 114.2, 120.6, 122.6, 122.6, 127.4, 129.6,
131.8, 144.9, 149.1, 157.5, 158.3, 161.7, 195.9. IR (νmax
cm−1): 3460, 3221, 3191, 2966, 2192, 1670, 1372, 1027.
HRMS calc. for [C31H35N5O3+Na]: 548.2632, found:
548.2629.
2-amino-7,7-dimethyl-5-oxo-4-{4-methoxy-3-[(1-(S)-
4-perillyl-methyl)-1H-1,2,3-triazol-4-yl]methoxyphenyl}-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (15e)
1
Yield: 78%, pale yellow solid, m.p. 93ꢀC-94ꢀC. H RMN
(CDCl3, 400 MHz): δ 1.03 (s, 3H, CH3), 1.07 (s, 3H,
CH3), 1.37-1.47 (m, 1H, perillyl-H), 1.70 (s, 3H,
H2C C CH3), 1.76-1.80 (m, 1H, perillyl-H), 1.89-1.99
(m, 3H, (CH3)2C CH2 + perillyl-H), 2.07-2.11 (m, 2H,
perillyl-H), 2.14-2.18 (m, 2H, perillyl-H), 2.38 (d,
J = 16.0 Hz, 1H, CH2 C O), 2.56 (d, J = 16.0 Hz, 1H,
2-amino-7,7-dimethyl-5-oxo-4-{4-[(1-(S)-perillyl-methyl)-
1H-1,2,3-triazol-4-yl]me thoxylphenyl}-
CH2 C O), 3.80 (s, 3H,
OCH3), 4.30 (s, 1H,
5,6,7,8-tetrahydro-4H-cromene-3-carbonitrile (15c)
C CH C ), 4.69 (d, J = 12.0 Hz, 2H, C CH2), 4.80
(brs, 2H, NH2), 4.85 (brs, 2H, OCH2 ), 5.26 (s, 2H,
N CH2 C ), 5.72 (s, 1H, C CH , 6.76-6.78 (m, 1H,
aromatic-H), 6.84-6.86 (m, 2H, aromatic-H), 7.59 (s, 1H,
C CH N ). 13C RMN (CDCl3, 100 MHz): δ 20.9, 26.6,
27.3, 28.2, 28.8, 30.7, 32.4, 35.2, 40.8, 50.9, 56.1, 56.7, 63.1,
63.1, 63.2, 77.5, 109.2, 111.8, 114.0, 119.2, 121.2, 123.2,
127.6, 132.0, 136.4, 144.5, 147.6, 148.8, 149.3, 158.0, 161.9,
196.4. IR (νmax cm−1): 3340, 3181, 2948, 2332, 2201, 1689,
1372, 1138, 1017. HRMS calc. for [C32H37N5O4+Na]:
578.2738, HRMS found: 578.2735.
1
Yield: 76%, pale yellow solid, m.p. 86ꢀC-88ꢀC. H NMR
(CDCl3, 400 MHz): δ 1.03 (s, 3H, CH3), 1.10 (s, 3H,
CH3), 1.41-1.51 (m, 1H, perillyl-H), 1.73 (s, 3H,
H2C C CH3), 1.80-1.84 (m, 1H, perillyl-H), 1.94-2.05
(m, 3H, (CH3)2C CH2 + perillyl-H), 2.11-2.17 (m, 2H,
perillyl-H), 2.21-2.26 (m, 2H, perillyl-H), 2.44 (s, 2H,
CH2 C O), 4.36 (s, 1H, C CH C ), 4.59-4.62 (m,
2H, NH2), 4.72 (d, J = 16.0 Hz, 2H, C CH2), 4.83 (s,
2H, OCH2 ), 5.17 (s, 2H, N CH2 C ), 5.77 (s, 1H,
C CH ), 6.90 (d, J = 8.0 Hz, 2H, aromatic-H), 7.16 (d,
J = 8.0 Hz, 2H, aromatic-H), 7.56 (s, 1H, C CH N ).
13C NMR (CDCl3, 100 MHz): δ 20.7, 26.3, 27.0, 27.6, 28.8,
30.4, 32.1, 34.7, 40.4, 50.6, 56.5, 62.1, 63.4, 77.2, 109.0,
114.1, 114.7, 118.8, 122.4, 127.4, 128.7, 131.8, 136.1, 144.4,
149.1, 157.2, 161.3, 196.1. IR (νmax cm−1): 3340, 3172,
2948, 2360, 2183, 1679, 1558, 1372, 1222. HRMS calc. for
[C31H35N5O3+Na]: 548.2632, found: 548.2632.
Ethyl-2-amino-7,7-dimethyl-5-oxo-4-{2-[(1-(S)-perillyl-
methyl)-1H-1,2,3-triazol-4-yl]methoxyphenyl}-
5,6,7,8-tetrahydro-4H-chromene-3-carboxylate (15f)
1
Yield: 80%, pale yellow solid, m.p. 80ꢀC-81ꢀC. H RMN
(CDCl3, 400 MHz): δ 0.96 (s, 3H, CH3), 1.05 (s, 3H,
CH3), 1.13 (t, J = 8.0 Hz, 3H, OCH2CH3), 1.38-1.50
(m, 1H, perillyl-H), 1.72 (s, 3H, H2C C CH3), 1.79-1.86
2-amino-7,7-dimethyl-5-oxo-4-{3-methoxy-4-[(1-(S)-
4-perillyl-methyl)-1H-1,2,3-triazol-4-yl]methoxyphenyl}-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (15d)
(m,
1H,
perillyl-H),
1.95-2.01
(m,
3H,
(CH3)2C CH2 + perillyl-H), 2.07-2.11 (m, 2H, perillyl-
H), 2.12-2.14 (m, 2H, perillyl-H), 2.19-2.23 (m, 2H,
CH2 C O), 3.92-4.04 (m, 2H, COOCH2 ), 4.69 (s,
1
Yield: 82%, pale yellow solid, m.p. 89ꢀC-90ꢀC. H RMN
(CDCl3, 400 MHz): δ 1.03 (s, 3H, -CH3), 1.09 (s, 3H,
CH3), 1.39-1.49 (m, 1H, perillyl-H), 1.71 (s, 3H,
H2C C CH3), 1.77-1.82 (m, 1H, perillyl-H), 1.91-2.01
(m, 3H, (CH3)2C CH2 + perillyl-H), 2.09-2.13 (m, 2H,
perillyl-H), 2.14-2.22 (m, 2H, perillyl-H), 2.43 (s, 2H,
1H,
C CH C ), 4.73-4.79 (m, 2H,
C CH2),
4.81-4.92 (m, 2H, OCH2 ), 5.14 (s, 2H, N CH2 C ),
5.76 (s, 1H, C CH ), 6.03 (brs, 2H, NH2), 6.86 (t,
J = 8.0 Hz, 2H, aromatic-H), 7.09 (t, J = 8.0 Hz, 1H,
aromatic-H), 7.33 (d, J = 8.0 Hz, 1H, aromatic-H), 7.68 (s,
1H, C CH N ). 13C RMN (CDCl3, 100 MHz): δ 14.1,
20.7, 26.3, 27.0, 27.1, 29.1, 30.4, 30.4, 32.1, 40.3, 40.4, 50.7,
56.3, 59.5, 77.2, 79.3, 109.1, 111.3, 111.4, 114.4, 120.2,
127.0, 127.1, 127.4, 132.2, 132.4, 148.8, 148.8, 156.1, 158.6,
161.9, 169.5, 196.6. IR (νmax cm−1): 3480, 3274, 2957,
CH2 C O), 3.85 (s, 3H,
C CH C ), 4.69-4.72 (m, 2H, C CH2), 4.76 (brs,
2H, NH2), 4.82 (s, 2H, OCH2 ), 5.23 (s, 2H,
OCH3), 4.32 (s, 1H,
N CH2 C ), 5.74 (s, 1H, C CH ), 6.65-6.68 (m,
1H, aromatic-H), 6.82 (d, J = 2.0 Hz, 1H, aromatic-H),

PACZKOWSKI ET AL.
15
1698, 1185, 1027. HRMS calc. for [C33H40N4O5+Na]:
595.2891, HRMS found: 595.2896.
Ethyl-2-amino-7,7-dimethyl-5-oxo-4-{3-methoxy-
4-[(1-(S)-4-perillyl-me- thyl)-1H-1,2,3-triazol-4-yl]
methoxyphenyl}-5,6,7,8-tetrahydro-4H-chromene-
Ethyl-2-amino-7,7-dimethyl-5-oxo-4-{3-[(1-(S)-perillyl-
methyl)-1H-1,2,3-triazol-4-yl]methoxyphenyl}-
3-carboxylate (15i)
1
Yield: 83%, pale yellow solid, m.p. 62ꢀC-64ꢀC. H RMN
(CDCl3, 400 MHz): δ 0.99 (s, 3H, CH3), 1.10 (s, 3H,
CH3), 1.18 (t, J = 8.0 Hz, 3H, OCH2CH3), 1.42-1.49
(m, 1H, perillyl-H), 1.73 (s, 3H, H2C C CH3), 1.79-1.84
5,6,7,8-tetrahydro-4H-chromene-3-carboxylate (15g)
1
Yield: 72%, pale yellow solid, m.p. 67ꢀC-68ꢀC. H RMN
(CDCl3, 400 MHz): δ 0.97 (s, 3H, CH3), 1.07 (s, 3H,
CH3), 1.15 (t, J = 8.0 Hz, 3H OCH2CH3), 1.39-1.50 (m,
1H, perillyl-H), 1.71 (s, 3H, H2C C CH3), 1.78-1.82 (m,
(m,
1H,
perillyl-H),
1.93-2.00
(m,
3H,
(CH3)2C CH2 + perillyl-H), 2.14-2.16 (m, 2H, perillyl-
H), 2.17-2.22 (m, 2H, perillyl-H), 2.33 (d, J = 8.0 Hz, 1H,
CH2 C O), 2.37 (d, J = 8.0 Hz, 1H, CH2 C O),
3.85 (s, 3H, OCH3), 4.02-4.08 (m, 2H, COOCH2 ),
4.65 (s, 1H, C CH C ), 4.70-4.73 (m, 2H, C CH2),
4.82 (brs, 2H, OCH2 ), 5.23 (d, J = 4.0 Hz, 2H,
N CH2 C ), 5.75 (s, 1H, C CH ), 6.16 (s, 2H,
NH2), 6.70 (dd, J = 6.0 and 2.0 Hz, 1H, aromatic-H),
6.87-6.90 (m, 2H, aromatic-H), 7.59 (s, 1H,
C CH N ). 13C RMN (CDCl3, 100 MHz): δ 14.3, 20.7,
26.4, 27.3, 29.1, 30.4, 31.2, 32.2, 33.3, 40.5, 50.7, 55.9, 56.4,
59.6, 63.4, 77.2, 80.8, 109.0, 112.6, 113.7, 115.6, 116.8,
119.9, 122.5, 127.4, 131.8, 139.8, 144.8, 145.9, 149.1, 158.3,
161.3, 169.1, 196.5, IR (νmax cm−1): 3423, 2938, 2341,
1689, 1372, 1027. HRMS calc. for [C34H42N4O6+Na]:
625.2997, HRMS found: 625.2996.
1H,
perillyl-H),
1.92-2.02
(m,
3H,
(CH3)2C CH2 + perillyl-H), 2.09-2.16 (m, 2H, perillyl-
H), 2.19-2.23 (m, 2H, perillyl-H), 2.38 (d, J = 18.0 Hz, 1H,
CH2 C O), 2.45 (d, J = 18.0 Hz, 1H, CH2 C O),
3.99-4.09 (m, 2H,
C CH2 C CH C ), 4.83 (s, 2H, OCH2 ),
5.12-5.19 (m, 2H, N CH2 C ), 5.75 (s, 1H,
COOCH2 ), 4.66-4.73 (m, 3H,
+
C CH ), 6.23 (brs, 2H, NH2), 6.71-6.73 (m, 1H,
aromatic-H), 6.88-6.90 (m, 2H, aromatic-H), 7.11 (t,
J = 8.0 Hz, 1H, aromatic-H), 7.59 (s, 1H, C CH N ).
13C RMN (CDCl3, 100 MHz): δ 14.2, 20.6, 26.3, 27.0, 27.5,
28.8, 30.4, 32.1, 33.7, 40.4, 50.7, 56.4, 59.6, 61.9, 77.2, 80.4,
108.9, 112.2, 114.8, 116.5, 121.3, 122.5, 127.3, 128.6, 131.8,
144.4, 147.5, 149.0, 157.8, 158.3, 161.4, 169.0, 196.3. IR
(νmax cm−1): 3386, 2948, 2351, 1689, 1558, 1213. HRMS
calc. for [C33H40N4O5+Na]: 595.2891, HRMS found:
595.2884.
Ethyl-2-amino-7,7-dimethyl-5-oxo-4-{4-metoxi-3-[(1-(S)-
perillyl-methyl)-1H-1,2,3-triazol-4-yl]methoxyphenyl}-
5,6,7,8-tetrahydro-4H-chromene-3-carbo-xylate (15j)
Ethyl-2-amino-7,7-dimethyl-5-oxo-4-{4-[(1-(S)-perilil-
methyl)-1H-1,2,3-triazol-4-yl]methoxyphenyl}-
5,6,7,8-tetrahydro-4H-chromene-3-carboxylate (15h)
1
Yield: 76%, pale yellow solid, m.p. 70ꢀC-72ꢀC. H RMN
(CDCl3, 400 MHz): δ 0.99 (s, 3H, CH3), 1.09 (s, 3H,
CH3), 1.17 (t, J = 8.0 Hz, 3H, OCH2CH3), 1.41-1.49
(m, 1H, perillyl-H), 1.72 (s, 3H, H2C C CH3),
1.77-1.82 (m, 1H, perillyl-H), 1.92-2.02 (m, 3H,
1
Yield: 69%, pale yellow solid, m.p. 74ꢀC-76ꢀC. H RMN
(CDCl3, 400 MHz): δ 0.94 (s, 3H, CH3), 1.06 (s, 3H,
CH3), 1.14 (t, J = 8.0 Hz, 3H, OCH2CH3), 1.39-1.49
(m, 1H, perillyl-H), 1.69 (s, 3H, H2C C CH3),
1.76-1.81 (m, 1H, perillyl-H), 1.91-2.01 (m, 3H,
(CH3)2C CH2 + perillyl-H), 2.09-2.15 (m, 2H, perillyl-
H), 2.18-2.23 (m, 2H, perillyl-H), 2.39 (s, 2H,
CH2 C O), 3.92-4.00 (m, 2H, COOCH2 ), 4.62 (s,
1H, C CH C ), 4.69 (d, J = 12.0 Hz, 2H, C CH2),
4.81 (brs, 2H, OCH2 ), 5.11 (s, 2H, N CH2 C ),
5.74 (s, 1H, C CH ), 6.24 (s, 2H, NH2), 6.80 (d,
J = 8.0 Hz, 2H, aromatic-H), 7.15 (d, J = 8.0 Hz, 2H,
aromatic-H), 7.55 (s, 1H, C CH N ). 13C RMN
(CDCl3, 100 MHz): δ 14.1, 20.6, 26.2, 26.9, 28.9, 30.3,
32.1, 32.8, 40.3, 50.5, 56.3, 59.4, 61.9, 77.2, 80.5, 108.9,
113.8, 115.4, 116.6, 122.3, 127.2, 129.1, 131.7, 138.7,
144.4, 148.9, 156.4, 158.2, 161.2, 169.0, 196.2. IR (νmax
cm−1): 3405, 3311, 2957, 1689, 1381, 1036. HRMS calc.
for [C33H40N4O5+Na]: 595.2891, HRMS found:
595.2889.
(CH3)2C CH2
+ perillyl-H), 2.12-2.14 (m, 2H,
perillyl-H), 2.16-2.23 (m, 2H, perillyl-H), 2.40 (d,
J = 18.0 Hz, 1H, CH2 C O), 2.54 (d, J = 18.0 Hz,
1H, CH2 C O), 3.80 (s, 3H, OCH3), 3.99-4.09 (m,
2H, COOCH2 ), 4.63 (s, 1H, C CH C ), 4.71 (d,
J = 14.0 Hz, 2H, C CH2), 4.83 (s, 2H, OCH2 ), 5.24
(t, J = 14.0 Hz, 2H, N CH2 C ), 5.74 (s, 1H,
C CH ), 6.17 (s, 2H, NH2), 6.73 (d, J = 8.0 Hz, 1H,
aromatic-H), 6.87-6.92 (m, 2H, aromatic-H), 7.63 (s,
1H, C CH N ). 13C RMN (CDCl3, 100 MHz): δ
14.3, 20.7, 26.3, 27.0, 27.6, 28.8, 30.4, 32.2, 33.2, 40.4,
50.7, 55.8, 56.4, 59.6, 63.1, 77.2, 80.7, 109.0, 111.0,
114.2, 116.6, 121.5, 122.7, 127.3, 131.8, 138.7, 144.5,
146.9, 147.7, 149.1, 158.2, 161.4, 169.1, 196.5. IR (νmax
cm−1): 3414, 3293, 2948, 1689, 1195, 1027. HRMS calc.
for [C34H42N4O6+Na]: 625.2997, HRMS found:
625.2999.

16
PACZKOWSKI ET AL.
2-amino-5-oxo-4-{2-[(1-(S)-perillyl-methyl)-1H-
1,2,3-triazol-4-yl]methoxyphe nyl}-5,6,7,8-tetrahydro-4H-
chromene-3-carbonitrile (15k)
OCH2 ), 5.17 (s, 2H, N CH2 C ), 5.77 (s, 1H,
C CH ), 6.91 (d, J = 8.0 Hz, 2H, aromatic-H), 7.17
(d,
J = 8.0 Hz, 2H, aromatic-H), 7.61 (s, 1H,
Yield: 79%, pale yellow solid, m.p. 132ꢀC-133ꢀC. 1H RMN
(CDCl3, 400 MHz): δ 1.37-1.47 (m, 1H, perillyl-H), 1.71
(s, 3H, H2C C CH3), 1.77-1.80 (m, 1H, perillyl-H),
1.92-1.96 (m, 3H, perillyl-H), 1.97-1.98 (m, 2H, perillyl-
H), 2.08-2.19 (m, 2H, CH2 CH2 C ), 2.29-2.31 (m,
2H, CH2 CH2 CH2 ), 2.45 (s, 2H, CH2 C O), 4.60
(s, 2H, NH2), 4.68 (s, 1H, C CH C ), 4.71 (brs, 2H,
C CH2), 4.82 (brs, 2H, OCH2 ), 5.20-5.28 (m, 2H,
N CH2 C ), 5.73 (s, 1H, C CH ), 6.86-6.93 (m,
2H, aromatic-H), 7.09-7.16 (m, 2H, aromatic-H), 7.76 (s,
1H, C CH N ). 13C RMN (CDCl3, 100 MHz): δ 20.1,
20.6, 26.2, 26.8, 26.9, 30.3, 30.6, 30.6, 36.7, 40.3, 56.3, 61.7,
61.7, 61.9, 108.9, 112.1, 113.9, 121.0, 127.1, 128.2, 129.2,
131.2, 131.8, 131.9, 149.0, 155.5, 158.0, 164.0, 196.1 IR
(νmax cm−1): 3396, 3311, 3181, 2938, 2192, 1661, 1362,
1204. HRMS calc. for [C29H31N5O3+Na]: 520.2319,
HRMS found: 520.2322.
C CH N ). 13C RMN (CDCl3, 100 MHz): δ 20.1,
20.7, 26.3, 27.0, 27.1, 29.7, 30.4, 34.6, 36.8, 40.4, 56.5,
62.2, 62.3, 63.6, 109.0, 114.8, 115.4, 127.4, 128.7, 131.8,
136.1, 149.1, 156.6, 157.3, 163.0, 164.7, 196.1. IR (νmax
cm−1): 3340, 3134, 2938, 2341, 2174, 1670, 1353. HRMS
calc. for [C29H31N5O3+Na]: 520.2319, HRMS found:
520.2314.
2-amino-5-oxo-4-{3-methoxy-4-[(1-(S)-perillyl-methyl)-
1H-1,2,3-triazol-4-yl]me thoxylphenyl}-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (15n)
Yield: 84%, pale yellow solid, m.p. 118ꢀC-120ꢀC. 1H RMN
(CDCl3, 400 MHz): δ 1.38-1.49 (m, 1H, perillyl-H), 1.71
(s, 3H, H2C C CH3), 1.77-1.81 (m, 1H, perillyl-H),
1.87-1.95 (m, 3H, perillyl-H), 1.98-2.07 (m, 2H, perillyl-
H), 2.09-2.20 (m, 2H,
(m, 2H, CH2 CH2 CH2 ), 2.50-2.61 (m, 2H,
CH2 C O), 3.86 (s, 3H, OCH3), 4.35 (s, 1H,
C CH C ), 4.68-4.72 (m, 2H, C CH2), 4.77 (s, 2H,
NH2), 4.81 (brs, 2H, OCH2 ), 5.23 (s, 2H,
CH2 CH2 C ), 2.28-2.41
2-amino-5-oxo-4-{3-[(1-(S)-perillyl-methyl)-1H-
1,2,3-triazol-4-yl]methoxyphe nyl}-5,6,7,8-tetrahydro-4H-
chromene-3-carbonitrile (15l)
N CH2 C ), 5.74 (s, 1H, C CH ), 6.65 (dd, J = 6.0
and 2.0 Hz, 1H, aromatic-H), 6.85 (d, J = 2.0 Hz, 1H,
aromatic-H), 6.93 (d, J = 8.0 Hz, 1H, aromatic-H), 7.58 (s,
1H, C CH N ). 13C RMN (CDCl3, 100 MHz): δ 20.1,
20.7, 26.3, 26.8, 26.9, 27.0, 30.3, 34.8, 36.7, 40.4, 55.9, 56.4,
62.8, 63.2, 108.9, 111.7, 111.8, 114.0, 114.1, 115.1, 119.1,
127.4, 131.7, 137.1, 146.4, 146.5, 149.0, 149.1, 157.5, 163.2,
196.2, IR (νmax cm−1): 3368, 2957, 2201, 1679, 1362, 1008,
HRMS calc. for [C30H33N5O4+Na]: 550.2425, HRMS
found: 550.2419.
Yield: 81%, pale yellow solid, m.p. 146ꢀC-148ꢀC. 1H-RMN
(CDCl3, 400 MHz): δ 1.40-1.50 (m, 1H, perillyl-H), 1.72
(s, 3H, H2C C CH3), 1.80-1.83 (m, 1H, perillyl-H),
1.88-1.96 (m, 2H, perillyl-H), 1.99-2.04 (m, 3H, perillyl-
H), 2.11-2.21 (m, 2H, CH2 CH2 C ), 2.29-2.40 (m,
2H,
CH2 CH2 CH2 ),
2.49-2.66
(m,
2H,
CH2 C O), 4.38 (s, 1H, C CH C ), 4.69 (s, 2H,
NH2), 4.74 (d, J = 16.0 Hz, 2H, C CH2), 4.84 (brs,
2H, OCH2 ), 5.19 (s, 2H, N CH2 C ), 5.76 (s, 1H,
C CH ), 6.81-6.89 (m, 3H, aromatic-H), 7.20 (t,
J = 8.0 Hz, 1H, aromatic-H), 7.61 (s, 1H, C CH N ).
13C RMN (CDCl3, 100 MHz): δ 20.0, 20.7, 20.7, 26.3, 26.9,
27.1, 30.4, 35.3, 36.7, 40.4, 56.4, 62.0, 62.8, 62.8, 109.0,
113.3, 114.2, 114.9, 120.6, 122.6, 127.3, 129.5, 131.8, 145.0,
149.0, 157.6, 158.3, 163.5, 195.9. IR (νmax cm−1): 3451,
3321, 3200, 2929, 2174, 1679, 1353, 1008. HRMS calc. for
[C29H31N5O3+Na]: 520.2319, HRMS found: 520.2327.
2-amino-5-oxo-4-{4-methoxy-3-[(1-(S)-perillyl-methyl)-
1H-1,2,3-triazol-4-yl]me thoxylphenyl)-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (15o)
1
Yield: 82%, pale yellow solid, m.p. 83ꢀC-84ꢀC. H RMN
(CDCl3, 400 MHz): δ 1.37-1.47 (m, 1H, perillyl-H), 1.70
(s, 3H, H2C C CH3), 1.77-1.80 (m, 1H, perillyl-H),
1.89-1.97 (m, 3H, perillyl-H), 1.97-2.03 (m, 2H, perillyl-
H),
2.08-2.18
(m,
2H,
perillyl-H),
2.29-2.35
2-amino-5-oxo-4-{4-[(1-(S)-perillyl-methyl)-1H-
(m 2H,
CH2 CH2 C ), 2.48-2.56 (m, 2H,
1,2,3-triazol-4-yl]methoxyphe nyl}-5,6,7,8-tetrahydro-4H-
chromene-3-carbonitrile (15m)
CH2 CH2 CH2 ), 2.66-2.71 (m, 2H, CH2 C O),
3.81 (s, 3H, OCH3), 4.31 (s, 1H, C CH C ), 4.69 (d,
J = 14.0 Hz, 2H, C CH2), 4.80 (s, 2H, NH2), 4.83 (s,
2H, OCH2 ), 5.28 (d, J = 2.0 Hz, 2H, N CH2 C ),
5.72 (s, 1H, C CH ), 6.78 (d, J = 8.0 Hz, 1H, aromatic-
H), 6.87 (d, J = 8.0 Hz, 2H, aromatic-H), 7.59 (s, 1H,
C CH N ). 13C RMN (CDCl3, 100 MHz): δ 20.0, 20.6,
26.3, 27.0, 27.0, 30.3, 34.8, 36.7, 40.4, 55.8, 56.4, 62.8, 62.9,
108.9, 111.4, 113.5, 114.8, 118.9, 120.9, 122.9, 127.3, 131.7,
136.0, 144.2, 147.2, 148.4, 149.0, 157.6, 163.4, 196.2, IR
Yield: 77%, pale yellow solid, m.p. 129ꢀC-130ꢀC. 1H
RMN (CDCl3, 400 MHz): δ 1.41-1.51 (m, 1H, perillyl-H),
1.73 (s, 3H, H2C C CH3), 1.80-1.84 (m, 1H, perillyl-H),
1.94-1.99 (m, 3H, perillyl-H), 2.00-2.07 (m, 2H, perillyl-
H), 2.11-2.23 (m, 2H, CH2 CH2 C ), 2.29-2.41 (m,
2H,
CH2 CH2 CH2 ),
2.51-2.65
(m,
2H,
CH2 C O), 4.39 (s, 1H, C CH C ), 4.61 (s, 2H,
NH2), 4.72 (d, J = 16.0 Hz, 2H, C CH2), 4.85 (s, 2H,

PACZKOWSKI ET AL.
17
(νmax cm−1): 3423, 2929, 2341, 2183, 1652, 1567, 1148.
HRMS calc. for [C30H33N5O4+Na]: 550.2425, HRMS
found: 550.2422.
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SUPPORTING INFORMATION
Additional supporting information may be found online
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How to cite this article: Paczkowski IM,
Guedes EP, Mass EB, et al. Synthesis of hybrid
perillyl-4H-pyrans. Cytotoxicity evaluation against
hepatocellular carcinoma HepG2/C3A cell line.
J Heterocyclic Chem. 2020;1–18. https://doi.org/10.
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