Design, synthesis and cytotoxic evaluation of 4-methylidenepyrazolidin-3-ones

Article abstract of DOI:10.1016/j.ejmech.2015.01.029

Three series of new 4-methylidenepyrazolidin-3-ones with various substitution patterns were synthesized and tested for the cytotoxic activity against two human leukemia cell lines NALM-6 and HL-60 as well as MCF-7 breast cancer cell line. Several obtained

Full text of DOI:10.1016/j.ejmech.2015.01.029

European Journal of Medicinal Chemistry 92 (2015) 565e574
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Design, synthesis and cytotoxic evaluation of 4-
methylidenepyrazolidin-3-ones
a
a
b
b
ꢀ_
Jakub Modranka , Rafał Jakubowski , Marek Rozalski , Urszula Krajewska ,
Anna Janecka c, Katarzyna Gach c, Dorota Pomorska c, Tomasz Janecki a
ꢀ ꢀ
Institute of Organic Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Łodz, Poland
Department of Pharmaceutical Biochemistry, Medical University of Łodz, Muszynskiego 1, 90-151 Łodz, Poland
Department of Biomolecular Chemistry, Medical University of Łodz, Mazowiecka 6/8, 92-215 Łodz, Poland
,
*
a
_
b
c
ꢀ ꢀ
ꢀ
ꢀ ꢀ
ꢀ ꢀ ꢀ ꢀ
a r t i c l e i n f o
a b s t r a c t
Article history:
Three series of new 4-methylidenepyrazolidin-3-ones with various substitution patterns were synthe-
sized and tested for the cytotoxic activity against two human leukemia cell lines NALM-6 and HL-60 as
well as MCF-7 breast cancer cell line. Several obtained methylidenepyrazolidinones exhibited high
Received 12 September 2014
Received in revised form
12 January 2015
Accepted 13 January 2015
Available online 14 January 2015
cytotoxic activity with IC50 values below 10
mM, mainly against HL-60 leukemia cell line and two of them,
18d,e, displayed IC50 ꢀ 5 M, against all tested cell lines. Structureeactivity relationship studies revealed
m
that the presence of phenyl substituents on both ring nitrogen atoms and vinyl or phenyl substituents in
position 5 are crucial for high activity. Selected methylidenepyrazolidinones were also tested on normal
human umbilical vein endothelial cells (HUVEC) and pyrazolidinone 18a was found to be 5-fold more
toxic against HL-60 than normal cells.
Keywords:
<alpha-Methylidene-<gamma>-lactams
Pyrazolidinones
Cytotoxicity
© 2015 Elsevier Masson SAS. All rights reserved.
Structureeactivity relationship
1. Introduction
containing additional nitrogen atom in the g-lactone ring in hope of
getting compounds with enhanced biological activity. Gratifyingly,
certain isoxazolidinones 3 proved to be very potent against several
cancer cell lines such as human leukemia HL-60 and NALM-6 cells
or breast cancer, MCF-7 and MDA-MB-231 cells [12]. Furthermore,
the most active compounds have been subjected to extended bio-
logical studies which have shed light on their mode of action at the
molecular level. In particular, Caspase-3 activity assay revealed that
isoxazolidinones 3 were able to induce apoptosis process in time-
and concentrationedependent manner. In addition, cytotoxicity
data obtained for drug-sensitive and drug-resistant HL-60 ADR
cells revealed that the investigated compounds were poor sub-
strates for transport by MRP1 efflux pump, suggesting that they
might be useful for treating drug-resistant tumors [13]. Also,
comparative studies of 4-methylideneisoxazolidin-5-one 3a
(R1 ¼ i-Pr, R2 ¼ Me) and Parthenolide 4 e the major sesquiterpene
lactone present in feverfew (Tanacetum parthenium) were per-
formed [14,15]. These studies showed, for example, that both
compounds dose-dependently inhibited incorporation of [3H]
thymidine, up-regulated Bax and down regulated Bc1-2 mRNA and
the effect produced by 3a was much stronger compared with Par-
a
-Alkylidene-
basic skeleton in many natural and synthetic compounds with
diverse biological properties [1,2]. In particular, many -alkylidene-
-lactones 1 or -lactams 2 exhibit strong anticancer activities due
g-lactone or g-lactam scaffold constitutes the
a
g
g
to their ability to act as the Michael acceptors towards various
bionucleophiles possessing mercapto groups, such as enzymes,
other proteins or free intracellular glutathione [3e6]. Such alkyl-
ation of cellular tiols can result in the disruption of many major
processes in the cells. Not surprisingly, great progress in the
development of new methodologies for the synthesis of these
classes of compounds can be noticed, especially from the beginning
of this century. Consequently, many natural as well as synthetic a-
alkylidenelactones and lactams were synthesized and their cyto-
toxicity was tested [7]. Also in our laboratory we have developed
synthesis of several classes of new a-alkylidenelactones and lac-
tams and many of the compounds obtained turned out to be highly
potent against several cancer cell lines [7e11]. Recently, we
designed
a
series of 4-methylideneisoxazolidin-5-ones
3
thenolide. These results show that simple analogs of
-lactones 1 containing additional nitrogen atom in the ring can be
good substitutes for more complex structures isolated from plants.
a-alkylidene-
g
* Corresponding author.
E-mail address: tomasz.janecki@p.lodz.pl (T. Janecki).
http://dx.doi.org/10.1016/j.ejmech.2015.01.029
0223-5234/© 2015 Elsevier Masson SAS. All rights reserved.

566
J. Modranka et al. / European Journal of Medicinal Chemistry 92 (2015) 565e574
diethoxyphosphorylacetates 10aec with phenylhydrazine hydro-
chloride (procedure a) or ethyl 2-acyl-2-
diethoxyphosphorylacetates 10def with phenylhydrazine (proce-
dure b) furnished pyrazolols 11aef in good yields. N-Methylation of
these compounds using methyl triflate followed by reduction of 2-
aryl-1-methylpyrazol-3-ones 12aef with L-Selectride gave Hor-
nereWadswortheEmmons reagents 13aef, which were obtained
as single trans isomers or mixtures of trans- and cis-di-
astereoisomers in 95:5 to 85:15 ratio. In view of the planned
transformation of pyrazolidinones 13 into methylidenepyr-
azolidinones 14aef no efforts were undertaken to separate the
diastereoisomers. In the last step, pyrazolidinones 13aef were used
for the olefination with formaldehyde, to provide final 5-
substituted pyrazolidinones 14aef in good yields.
Inspired by these findings and aiming to develop novel, effective
anticancer agents, we designed 4-methylidenepyrazolidin-3-ones
5 containing additional nitrogen atom in the -lactam ring.
Methylidene- -lactams are considered as particularly promising
anticancer agents because it is believed that the -lactam moiety
can help to mitigate the biological toxicity often observed for
2.1.3. Synthesis of 5-alkyl or 5-aryl-1,2-diphenyl-4-
methylidenepyrazolidin-3-ones 18aee
g
a-
1,2-Diphenyl-4-methylidenepyrazolidin-3-ones 18aee con-
taining alkyl or aryl substituent in position 5 were synthesized
starting from 3-methoxy-2-diethoxyphosphorylacrylate 15 [20]
and 1,2-diphenylhydrazine (Scheme 3). Heating the substrates in
boiling toluene gave expected 4-diethoxyphosphoryl-1,2-diphenyl-
1,2-dihydro-3H-pyrazol-3-one (16). Addition of Grignard reagents
to pyrazolone 16 in boiling THF yielded the expected 5-substituted
4-diethoxyphosphoryl-1,2-diphenylpyrazolidin-3-ones 17aee in
reasonable yields as pure trans or a mixtures of trans- and cis-iso-
mers in 95:5 to 85:15 ratio. Phosphorylated pyrazolidinones 17aee
were next used as HornereWadswortheEmmons reagents for the
olefination with formaldehyde to furnish the targeted 4-
methylidene-1,2-diphenylpyrazolidin-3-ones 18aee in excellent
yields.
g
g
g-
lactones [16,17]. On the other hand, we expected that the presence
of an additional nitrogen atom might enhance the activity because
g-lactams usually display lower cytotoxicity than corresponding
a-
alkylidene- -lactones [8e10].
g
To verify these assumptions we synthesized three series of
variously substituted 4-methylidenepyrazolidin-3-ones 9aed,
14aef and 18aee using methodologies recently developed in our
laboratory [18] and tested the obtained compounds for the cyto-
toxic activity against several cancer cell lines.
2. Results and discussion
The structures and purity of final compounds 9aed, 14aef and
18aee as well as all intermediates were confirmed by IR, 1H NMR,
13C NMR, ESI MS and elemental analyses.
2.1. Chemistry
2.1.1. Synthesis of 2-aryl-1-methyl-4-methylidenepyrazolidin-3-
ones 9aed
2.2. Cytotoxicity
Synthesis of 1-methyl-4-methylidenepyrazolidin-3-ones 9aed
substituted with various aryl groups in position 2 is shown in
Scheme 1. Starting 1-aryl-4-diethoxyphosphoryl-1H-pyrazol-5-ols
6aed, prepared according to the literature procedure described
for the corresponding 4-dimethoxyphosphorylpyrazol-5-ols [19],
were N-methylated with dimethyl sulfate to give 2-aryl-1-methyl-
4-diethoxyphosphorylpyrazol-3-ones 7aed. Reduction of the
double bond in pyrazolones 7 using L-selectride as a reducing agent
gave pyrazolidinones 8aed which were next used in Hor-
nereWadswortheEmmons olefination of formaldehyde yielding
the targeted 4-methylidenepyrazolidin-3-ones 9aed.
All obtained methylidenepyrazolidin-3-ones 9aed, 14aef and
18aee were tested in vitro against three human cancer cell lines:
leukemia NALM-6 and HL-60 as well as MCF-7 breast cancer and
results are shown in Table 1. Additionally, cytotoxicities of selected
3-methylidenepyrolidin-2-ones 19 and 4-methylideneisoxazolidin-
5-ones 20, recently prepared in our laboratory, are given for com-
parison. Carboplatin was used as a reference compound [21].
The IC50 values of methylidenepyrazolidin-3-ones vary
dramatically and depend on the nature of substituents in the pyr-
azolidinone ring. The least active are pyrazolidinones 14aec with
IC50 values over 100 mM against all three cell lines. These com-
2.1.2. Synthesis of 5-alkyl or 5-aryl-1-methyl-2-phenyl-4-
methylidenepyrazolidin-3-ones 14aef
1-Methyl-2-phenyl-4-methylidenepyrazolidin-3-ones
containing various alkyl or aryl substituents in position 5 were
synthesized according to Scheme 2. Reaction of ethyl 2-alkanoyl-2-
pounds have methyl and phenyl group attached to N-1 and N-2
nitrogen atom, respectively and short alkyl substituent (methyl,
ethyl or butyl) in position 5. Majority of the remaining pyr-
azolidinones have moderate activity with IC50 values falling in the
14aef
range between 91.1 and 24.4 mM. These pyrazolidinones also have
Scheme 1. Reagents and conditions: (a) Me2SO4 (1.2 equiv), DCE, 80 ꢁC, 18 h. (b) L-Selectride (1.25 equiv), THF, ꢂ78 ꢁC, 1 h, then r.t., 18 h. (c) (CH2O)n (5 equiv), NaH (1.2 equiv), THF,
r.t., 2 h.

J. Modranka et al. / European Journal of Medicinal Chemistry 92 (2015) 565e574
567
Scheme 2. Reagents and conditions: (a) 1. H2NNHPh ꢃ HCl, H2O, reflux, 2 h. 2. K2CO3 (2 equiv), 2 h, reflux, then 18 h, r.t. (b) H2NNHPh, AcOH (2 equiv), H2O, reflux, 3 h. (c) CF3SO3Me
(2 equiv), DCE, 80 ꢁC, 2 h. (d) L-Selectride (1.25 equiv), THF, ꢂ78 ꢁC, 1 h, then r.t., 18 h. (e) (CH2O)n (5 equiv), NaH (1.2 equiv), THF, 2 h, r.t.
Scheme 3. Reagents and conditions: (a) Toluene, reflux, 80 h. (b) RMgX (1.2 equiv), THF, reflux, 2 h. (c) NaH (1.2 equiv), (CH2O)n (5 equiv), THF, r.t., 2 h.
methyl and aryl group attached to nitrogen atoms but have n-nonyl
(14d), phenyl (14e) or no substituent (9aee) in position 5. No clear
structure activity relationship within this group can be found.
However, comparison between pyrazolidinones with low (14aec)
and moderate (9aee, 14d,e) activity shows that lack of the sub-
stituent in position 5 or presence of phenyl or n-nonyl group in this
position increases the activity approximately ten times against HL-
60 and NALM-6 cell lines and two to three times against MCF-7 cell
line. Pyrazolidinones 18aee with phenyl substituent attached to
each nitrogen atom displayed the highest activity. IC50 values in this
cells and pyrazolidinone 18a was also 5-fold less toxic against
HUVEC than against HL-60 cancer cells.
3. Conclusions
Three series of 4-methylidenepyrazolidin-3-ones 9, 14 and 18,
with different substitution patterns, were synthesized to verify the
assumption that additional nitrogen atom in the
might enhance, usually very low, cytotoxic activity of
idene- -lactams. Prepared compounds were tested for the cyto-
g-lactam ring
a
-methyl-
g
group vary from 29.1
m
M (18c, against NALM-6 cells) to 0.74
m
M
toxic activity against NALM-6 and HL-60 leukemia cell lines as well
as against MCF-7 breast cancer cell line. Many of them turned out to
be moderate or highly active, with IC50 values less than 50 mM,
(18d, against NALM-6 cells). Obviously, the presence of phenyl
substituent on each nitrogen atom enhances activity significantly.
Furthermore, additional unsaturated substituent in position 5 (vi-
nyl in 18d or phenyl in 18e) further enhances the activity. Clearly,
pyrazolidinones 18d,e are the most potent compounds against all
proving that additional nitrogen atom in the ring might be crucial
for high activity. Structure-activity studies revealed that the pres-
ence of phenyl group on both nitrogen atoms of the pyrazolidinone
ring highly increases activity. Further enhancement in the cytotoxic
activity was achieved by introducing vinyl or phenyl group in po-
sition 5. Tests on HUVEC cells showed that compounds 18a,d have
moderate therapeutic indexes (IC50HUVEC/IC50NALM-6 or IC50HL-
60 ~ 4e5). Currently, the most active 4-methylidenepyrazolidin-3-
ones are subjected to more advanced biological screenings, to
establish their mode of action. We believe that 4-
methylidenepyrazolidin-3-ones are a very promising group of
new anticancer agents and careful manipulations of their substi-
tution pattern might further improve both, anticancer activity and
therapeutic index.
three tested cell lines with IC50 values ranging from 4.5 to 0.74 mM.
Notably, when compared to carboplatin, these pyrazolidinones
exhibited superior or comparable activity against all three cell lines
tested.
Excellent anticancer activity of methylidenepyrazolidinones
18aee and in particular 18d,e and even moderate activity of 9aed
contrasts dramatically with low cytotoxicity usually displayed by 3-
methylidenepyrolidin-2-ones. For the comparison, cytotoxicities of
three methylidenepyrolidin-2-ones 19aec, tested previously in our
laboratory against HL-60 and NALM-6 cell lines are given in Table 1.
Clearly, introduction of the additional nitrogen atom to the lactam
ring is extremely beneficial for the activity. Another important
factor enhancing activity is the presence of phenyl substituents
attached to both nitrogen atoms. It is also worth to mention that
activity of methylidenepyrazolidinones 18dee is comparable to the
activity of 4-methylideneisoxazolidin-5-ones e highly active ana-
4. Materials and methods
4.1. Chemistry
logs of
a-methylidene-g-lactones containing additional nitrogen
4.1.1. General
atom in the lactone ring, which have been synthesized recently in
our laboratory. Cytotoxicity data for selected methylideneisox-
azolidin-5-ones 20aec are given in Table 1.
Finally, 4-methylidene-1,2-diphenylpyrazolidin-3-ones 18aee
which showed the highest activity against all three cancer cell lines
were tested on human umbilical vein endothelial cells (HUVEC), to
evaluate their toxicity against normal cells (Table 1). In most cases
toxicity of these compounds against normal cells was similar to the
toxicity against cancer cells. However, pyrazolidinones 18a and 18d
were 4-fold less toxic against HUVEC than against NALM-6 cancer
NMR spectra were recorded on a Bruker DPX 250 or Bruker
Avance II instrument at 250.13 MHz or 700 MHz for 1H, 62.9 MHz or
176 MHz for 13C, and 101.3 MHz for 31P NMR using tetramethylsi-
lane as internal and 85% H3PO4 as external standard. 31P NMR
spectra were recorded using broadband proton decoupling. IR
spectra were recorded on a Bruker Alpha ATR spectrophotometer.
Melting points were determined in open capillaries and are un-
corrected. Column chromatography was performed on Aldrich®
silica gel 60 (230e400 mesh). Thin-layer chromatography was
performed with precoated TLC sheets of silica gel 60 F254 (Aldrich®).

568
J. Modranka et al. / European Journal of Medicinal Chemistry 92 (2015) 565e574
Table 1
In vitro cytotoxic activity of pyrazolidinones 9aed, 14aef and 18aee tested on three cancer cell lines and on normal HUVEC cells.
R1
R2
R3
IC50
(
m
M)
a
Compd
HL-60
NALM-6
MCF-7
HUVEC
9a
9b
9c
9d
14a
14b
14c
14d
14e
14f
18a
18b
18c
18d
18e
H
H
H
H
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Ph
Ph
4-MeC6H4
4-ClC6H4
45.7 3.8
65.7 3.2
38.1 6.2
51.8 6.0
531 14
750 31
460 18
49.9 5.8
40.9 6.1
37.3 6.0
5.85 0.44
8.89 0.52
8.92 0.50
1.32 0.21
1.61 0.19
989 19
611 18
515 47
4.7 0.8
56.0 8.9
90.1 8.8
51.9 7.8
62.0 9.4
412 22
576 27
432 15
57.5 3.9
24.4 3.8
49.3 2.0
6.98 0.19
14.9 2.9
29.1 4.5
0.74 0.03
3.82 0.43
552 50
522 21
439 41
0.34 0.04
4.96 0.31
4.6 0.5
56.0 6.3
59.1 6.9
45.2 4.1
43.8 7.5
153 18
185 12
235 26
91.1 8.7
84.4 9.2
75.0 6.7
12.5 2.4
20.0 0.9
25.2 3.4
5.1 0.7
4.5 0.40
eb
eb
eb
eb
4-BrC6H4
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Me
Me
H
eb
Me
Et
n-Bu
n-nonyl
eb
eb
eb
eb
Ph
eb
4-MeOC6H4
Me
Et
n-Bu
vinyl
Ph
H
H
4-BrC6H4
2-pentyl
Ph
4-BrC6H4
e
eb
29.9 3.6
23.9 4.5
27.0 3.3
2.73 0.38
Ph
Ph
Ph
Ph
4.46 0.49
19ac
19bc
19cd
20ae
20be
20ce
Carboplatin
Ph
eb
eb
eb
eb
eb
eb
eb
4-MeC6H4
Me
Me
Me
Me
e
eb
eb
e
eb
e
34.8 3.6
5.1 0.5
2.9 0.1
eb
e
eb
e
0.7 0.3
3.8 0.45
a
Compound concentration required to inhibit tumor cell proliferation by 50%. Data are expressed as the mean SD from the concentrationeresponse curves of at least three
experiments.
b
c
Not determined.
Data taken from Ref. [9].
Data taken from Ref. [22].
Data taken from Ref. [12].
d
e
The purity of tested compounds was determined by combustion
elemental analyses (CHN, elemental analyzer EuroVector 3018,
Elementar Analysensysteme GmbH). Analyses indicated by the
symbols of the elements or functions were within 0.4% of the
theoretical values. MS spectra were performed on combined Wa-
ters 2695-Waters ZQ 2000 LC/MS apparatus. Reagents and starting
materials were purchased from commercial vendors and used
without further purification. All organic solvents were dried over
appropriate drying agents and distilled prior to use. Standard sy-
ringe techniques were used for transferring dry solvents.
J ¼ 4.5 Hz, H-5); 13C NMR (62.9 MHz, CDCl3):
d
16.1 (d, J ¼ 6.9,
(CH3CH2O)2P(O)), 37.2 (s, CH3), 62.2 (d, J ¼ 5.5, (CH3CH2O)2P(O)),
94.2 (d, J ¼ 222.5, C-4), 126.1 (s, 2ꢃ CeAr), 128.3 (s, CeAr) 129.3 (s,
2ꢃ CeAr), 132.7 (s, CeAr), 147.8 (d, J ¼ 18.5, C-5), 163.0 (d, J ¼ 13.9,
C-3); 31P NMR (101 MHz, CDCl3):
d 13.64. Anal. C14H19N2O4P (C, H,
N).
4.1.2.1.2. Diethyl
(1-methyl-3-oxo-2-(p-tolyl)-2,3-dihydro-1H-
pyrazol-4-yl)phosphonate (7b). Yellow oil. Yield: 67%; IR (film):
3035, 1655, 1509, 1258, 1029, 758, 542; 1H NMR (250 MHz, CDCl3):
d
1.25 (t, J ¼ 7.1, 6H, (CH3CH2O)2P(O)), 2.28 (s, 3H, CH3), 3.27 (s, 3H,
CH3), 4.06e4.14 (m, 4H, (CH3CH2O)2P(O)), 7.09 (d, J ¼ 8.2, 2H,
HeAr), 7.18 (d, J ¼ 8.2, 2H, HeAr), 7.84 (d, J ¼ 4.4, 1H, H-5); 13C NMR
4.1.2. Chemical synthesis
(62.9 MHz, CDCl3):
d
16.0 (d, J ¼ 6.9, (CH3CH2O)2P(O)), 20.8 (s, CH3),
4.1.2.1. General procedure for the synthesis of 2-aryl-1-methyl-4-
diethoxyphosphorylpyrazol-3-ones 7aed. A solution of corre-
sponding pyrazolol 6aed (5 mmol) and dimethyl sulfate (0.57 mL,
6 mmol) in 1,2-dichloroethane (50 mL) was heated in reaction
vessel at 80 ꢁC for 18 h. The solvent was evaporated and the crude
product was purified by column chromatography (eluent: EtOAc e
MeOH, 9:1).
36.9 (s, CH3), 62.0 (d, J ¼ 5.6, (CH3CH2O)2P(O)), 93.8 (d, J ¼ 222.2, C-
4), 126.3 (s, 2ꢃ CeAr), 129.8 (s, 2ꢃ CeAr), 130.0 (s, CeAr), 138.6 (s,
CeAr), 147.1 (d, J ¼ 18.8, C-5), 162.9 (d, J ¼ 14.0 Hz, C-3); 31P NMR
(101 MHz, CDCl3):
d 12.51. Anal. C15H21N2O4P (C, H, N).
4.1.2.1.3. Diethyl (2-(4-chlorophenyl)-1-methyl-3-oxo-2,3-
dihydro-1H-pyrazol-4-yl)phosphonate (7c). Yellow oil. Yield: 46%;
IR (film): 3016, 1642, 1491, 1254, 1011, 739, 551; 1H NMR (250 MHz,
4.1.2.1.1. Diethyl (1-methyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyr-
azol-4-yl)phosphonate (7a). Yellow oil. Yield: 54%; IR (film): 2980,
1661, 1544, 1486, 1255, 1148, 1017, 969, 738, 546; 1H NMR
CDCl3):
d
1.33 (t, J ¼ 7.0, 6H, (CH3CH2O)2P(O)), 3.32 (s, 3H, CH3),
4.12e4.25 (m, 4H, (CH3CH2O)2P(O)), 7.23e7.27 (m, 2H, HeAr),
7.41e7.50 (m, 2H, HeAr), 7.93 (d, J ¼ 4.5, 1H, H-5); 13C NMR
(250 MHz, CDCl3):
d
1.29 (t, J ¼ 7.0, 6H, (CH3CH2O)2P(O)), 3.36 (s, 3H,
(62.9 MHz, CDCl3):
d
16.0 (d, J ¼ 6.8, (CH3CH2O)2P(O)), 37.1 (s, CH3),
CH3), 4.10e4.17 (m, 4H, (CH3CH2O)2P(O)), 7.26e7.30 (m, 2H, HeAr),
7.38e7.40 (m, 1H, HeAr), 7.44e7.49 (m, 2H, HeAr), 7.93 (d, 1H,
62.1 (d, J ¼ 5.6, (CH3CH2O)2P(O)), 94.4 (d, J ¼ 222.6, C-4), 126.9 (s,

J. Modranka et al. / European Journal of Medicinal Chemistry 92 (2015) 565e574
569
2ꢃ CeAr), 129.3 (s, 2ꢃ CeAr), 131.3 (s, CeAr), 133.8 (s, CeAr), 148.8
(d, J ¼ 18.7, C-5), 162.9 (d, J ¼ 14.3, C-3); 31P NMR (101 MHz, CDCl3):
CeAr),165.5 (d, J ¼ 2.4, C-3); 31P NMR (101 MHz, DMSO-d6,100 ꢁC):
d
22.65. Anal. C14H20ClN2O4P (C, H, N).
d
12.07. Anal. C14H18ClN2O4P (C, H, N).
4.1. 2. 2. 4. Diethyl (2-(4-bromophenyl)-1-methyl-3-
4.1.2.1.4. Diethyl (2-(4-bromophenyl)-1-methyl-3-oxo-2,3-
oxopyrazolidin-4-yl)phosphonate (8d). Yellow oil. Yield: 79%; IR
dihydro-1H-pyrazol-4-yl)phosphonate (7d). Yellow oil. Yield: 63%;
(film): 2970, 1694, 1593, 1487, 1347, 1266, 1008, 966; 1H NMR
IR (film): 2983, 1647, 1487, 1223, 1013, 742, 556; 1H NMR (250 MHz,
(250 MHz, DMSO-d6, 100 ꢁC):
d
1.23 (t, J ¼ 7.0, 3H, (CH3CH2O)P(O)),
CDCl3):
d
1.38 (t, J ¼ 7.1, 6H, (CH3CH2O)2P(O)), 3.40 (s, 3H, CH3),
1.25 (t, J ¼ 7.0, 3H, (CH3CH2O)P(O)), 2.59 (s, 3H, CH3), 3.50e3.65 (m,
2H, 2ꢃ H-5), 3.82e4.03 (m, 1H, H-4), 4.05e4.20 (m, 4H,
4.18e4.30 (m, 4H, (CH3CH2O)2P(O)), 7.23e7.32 (m, 2H, HeAr),
7.64e7.68 (m, 2H, HeAr), 7.97 (d, J ¼ 4.6, 1H, H-5); 13C NMR
(CH3CH2O)2P(O)), 7.34e7.42 (m, 2H, HeAr), 7.62e7.73 (m, 2H,
13
(62.9 MHz, CDCl3):
d
16.0 (d, J ¼ 6.8, (CH3CH2O)2P(O)), 37.2 (s, CH3),
HeAr); C NMR (62.9 MHz, DMSO-d6, 100 ꢁC):
d
15.5 (d, J ¼ 5.5,
62.1 (d, J ¼ 5.7, (CH3CH2O)2P(O)), 94.6 (d, J ¼ 222.4, C-4), 121.8 (s,
CeAr), 127.1 (s, 2ꢃ CeAr), 131, 8 (s, 2ꢃ CeAr), 132.3 (s, CeAr), 149.0
(d, J ¼ 18.6, C-5), 162.9 (d, J ¼ 14.2, C-3); 31P NMR (101 MHz, CDCl3):
(CH3CH2O)2P(O)), 40.4 (d, J ¼ 146.9, C-4), 42.9 (s, CH3), 51.6 (d,
J ¼ 1.9, C-5), 61.6 (d, J ¼ 6.5, (CH3CH2O)P(O)), 62.0 (d, J ¼ 6.5,
(CH3CH2O)P(O)), 120.6 (s, 2ꢃ CeAr), 128.1 (s, 2ꢃ CeAr), 128.3 (s,
CeAr), 135.4 (s, CeAr), 165.5 (d, J ¼ 2.5, C-3); 31P NMR (101 MHz,
d
11.97. Anal. C14H18BrN2O4P (C, H, N).
DMSO-d6, 100 ꢁC):
d 22.72. Anal. C14H20BrN2O4P (C, H, N).
4.1.2.2. General procedure for the synthesis of 2-aryl-4-
diethoxyphosphoryl-1-methylpyrazolidin-3-ones 8aed, 13aef.
4.1.2.2.5. Diethyl (1,5-dimethyl-3-oxo-2-phenylpyrazolidin-4-yl)
phosphonate (13a). Yellow oil. Yield: 75%; IR (film): 3209, 2981,
1693, 1356, 1225, 1195, 1018, 966, 753; 1H NMR (250 MHz, CDCl3,
To a cooled (ꢂ78 ꢁC) solution of the corresponding pyrazolone
7aed, 13aef (2 mmol) in THF (25 mL) was added dropwise a 1 M
THF solution of L-Selectride (2.5 mmol, 2.5 mL) under argon at-
mosphere and the mixture was stirred at this temperature for 1 h.
Then, the mixture was allowed to slowly warm to room tempera-
ture and was stirred at room temperature overnight. The reaction
mixture was concentrated to a half of starting volume and
quenched with 10% aq NH4Cl. After extraction with CH2Cl2
(3 ꢃ 15 mL), the combined organic layers were washed with brine
and dried over MgSO4. The crude product was purified by column
chromatography (eluent: EtOAc e MeOH, 9:1).
trans isomer):
d 1.36 (m, 9H, CH3, (CH3CH2O)2P(O)), 2.66 (s, 3H,
NeCH3), 2.91 (bd, J ¼ 22.2 Hz, 1H, H-4), 3.45e3.83 (m, 1H, H-5),
4.14e4.38 (m, 4H, (CH3CH2O)2P(O)), 7.09e7.18 (m, 1H, HeAr),
7.28e7.38 (m, 2H, HeAr), 7.65e7.78 (m, 2H, HeAr); 13C NMR
(62.9 MHz, DMSO-d6, 100 ꢁC):
d
15.5 (d,
J
¼
5.5 Hz,
(CH3CH2O)2P(O)), 19.6 (t, J ¼ 9.1 Hz, CH3), 41.3 (s, NeCH3), 48.1 (d,
J ¼ 141.9 Hz, C-4), 58.0 (s, C-5), 61.6 (d, J ¼ 6.7 Hz, CH3CH2OP(O)),
62.1 (d, J ¼ 6.7 Hz, CH3CH2OP(O)), 120.3 (s, 2ꢃ CeAr), 124.5 (s,
CeAr), 128.2 (s, 2ꢃ CeAr), 136.8 (s, CeAr), 164.6 (d, J ¼ 3.4 Hz, C-3);
31P NMR (101 MHz, CDCl3):
d 21.28 (15%), 21.79 (85%). Anal.
4.1.2.2.1. Diethyl
(1-methyl-3-oxo-2-phenylpyrazolidin-4-yl)
C15H23N2O4P (C, H, N).
phosphonate (8a). Yellow oil. Yield: 86%; IR (film): 2982,1691,1594,
4.1.2.2.6. Diethyl (5-ethyl-1-methyl-3-oxo-2-phenylpyrazolidin-
4-yl)phosphonate (13b). Yellow oil. Yield: 75%; IR (film): 3220,
2966, 1691, 1492, 1354, 1247, 1019, 967, 753; 1H NMR (250 MHz,
1491, 1355, 1248, 1019, 963; 1H NMR (250 MHz, DMSO-d6, 100 ꢁC):
d
1.15 (t, J ¼ 7.2, 3H, (CH3CH2O)P(O)), 1.18 (t, J ¼ 7.0, 3H, (CH3CH2O)
P(O)), 2.51 (s, 3H, CH3), 3.45e3.63 (m, 2H, 2ꢃ H-5), 3.72e3.85 (m,
1H, H-4), 4.00e4.12 (m, 4H, (CH3CH2O)2P(O)), 7.00e7.07 (m, 1H,
HeAr), 7.23e7.29 (m, 2H, HeAr), 7.54e7.58 (m, 2H, HeAr); 13C NMR
CDCl3, trans isomer):
d
1.05 (t, J ¼ 7.3 Hz, 3H, CH3CH2), 1.40 (t,
J ¼ 7.1 Hz, 6H, (CH3CH2O)2P(O)), 1.50e1.77 (m, 2H, CH3CH2), 2.78 (s,
3H, NeCH3), 2.91 (dd, J ¼ 3.2 Hz, 24.6 Hz, 1H, H-4), 3.36e3.52 (m,
1H, H-5), 4.16e4.40 (m, 4H, (CH3CH2O)2P(O)), 7.11e7.20 (m, 1H,
HeAr), 7.32e7.42 (m, 2H, HeAr), 7.71e7.79 (m, 2H, HeAr); 13C NMR
(62.9 MHz, DMSO-d6, 100 ꢁC):
d
14.7 (d, J ¼ 5.4, (CH3CH2O)2P(O)),
39.6 (d, J ¼ 146.9, C-4), 42.1 (s, CH3), 50.9 (d, J ¼ 1.6, C-5), 60.7 (d,
J ¼ 6.6, (CH3CH2O)P(O)), 61.1 (d, J ¼ 6.4, (CH3CH2O)P(O)), 118.6 (s,
2ꢃ CeAr), 123.4 (s, CeAr) 127.4 (s, 2ꢃ CeAr), 135.8 (s, CeAr), 164.4
(176 MHz, CDCl3, trans isomer):
d
9.6 (s, CH3CH2), 16.3 (d, J ¼ 5.1 Hz,
CH3CH2OP(O)), 16.3 (d, J ¼ 5.1 Hz, CH3CH2OP(O)), 29.7 (bs, CH3CH2),
44.5 (bs, NeCH3), 48.7 (d, J ¼ 137.3 Hz, C-4), 62.4 (d, J ¼ 7.6 Hz,
CH3CH2OP(O)), 63.4 (d, J ¼ 6.4 Hz, CH3CH2OP(O)) 63.7 (s, C-5), 120.5
(s, 2ꢃ CeAr), 125.0 (s, CeAr), 128.7 (s, 2ꢃ CeAr), 137.0 (s, CeAr),
(d, J ¼ 2.3, C-3); 31P NMR (101 MHz, DMSO-d6, 100 ꢁC):
d 23.01.
Anal. C14H21N2O4P (C, H, N).
4.1.2.2.2. Diethyl
(1-methyl-3-oxo-2-(p-tolyl)pyrazolidin-4-yl)
phosphonate (8b). Yellow oil. Yield: 82%; IR (film): 2982, 1689,
164.4 (s, C-3); 31P NMR (101 MHz, CDCl3):
d 21.04 (5%), 22.04 (95%).
1614, 1508, 1354, 1248, 1018, 963; 1H NMR (250 MHz, DMSO-d6,
Anal. C15H25N2O4P (C, H, N).
100 ꢁC):
d
1.24 (t, J ¼ 7.0, 3H, (CH3CH2O)P(O)), 1.27 (t, J ¼ 7.0, 3H,
4.1.2.2.7. Diethyl (5-butyl-1-methyl-3-oxo-2-phenylpyrazolidin-
4-yl)phosphonate (13c). Yellow oil. Yield: 88%; IR (film): 3223,
2959, 2931, 1692, 1491, 1354, 1248, 1020, 967, 753; 1H NMR
(CH3CH2O)P(O)), 2.25 (s, 3H, CH3), 2.57 (s, 3H, CH3), 3.56 (dd,
J ¼ 14.5, 9.2, 2H, 2ꢃ H-5), 3.84 (dt, J ¼ 21.5, 9.2, 1H, H-4), 4.05e4.20
(m, 4H, (CH3CH2O)2P(O)), 7.13e7.20 (m, 2H, HeAr), 7.48e7.55 (m,
(250 MHz, CDCl3, trans isomer):
CH3CH2CH2CH2), 1.32e1.44 (m,
d
0.93 (t, J ¼ 7.3 Hz, 3H,
2H, HeAr); 13C NMR (62.9 MHz, DMSO-d6,100 ꢁC):
d
15.5 (d, J ¼ 5.6,
8H, CH3CH2CH2CH2,
(CH3CH2O)2P(O)), 19.8 (s, CH3), 40.4 (d, J ¼ 146.9, C-4), 42.9 (s, CH3),
51.7 (d, J ¼ 1.8, C-5), 61.5 (d, J ¼ 6.7, (CH3CH2O)P(O)), 61.9 (d, J ¼ 6.4,
(CH3CH2O)P(O)), 119.7 (s, 2ꢃ CeAr), 128.7 (s, 2ꢃ CeAr), 133.7 (s,
CeAr), 134.1 (s, CeAr), 164.9 (d, J ¼ 2.3, C-3); 31P NMR (101 MHz,
(CH3CH2O)2P(O)), 1.45e1.58 (m, 2H, CH3CH2CH2CH2), 1.62e1.78 (m,
2H, CH3CH2CH2CH2), 2.78 (s, 3H, NeCH3), 2.91 (dd, J ¼ 3.1 Hz,
24.6 Hz, 1H, H-4), 3.43e3.58 (m, 1H, H-5), 4.17e4.37 (m, 4H,
(CH3CH2O)2P(O)), 7.11e7.21 (m, 1H, HeAr), 7.32e7.42 (m, 2H,
HeAr), 7.71e7.78 (m, 2H, HeAr); 13C NMR (176 MHz, CDCl3, trans
DMSO-d6, 100 ꢁC):
d 23.13. Anal. C15H23N2O4P (C, H, N).
4.1. 2. 2. 3. Diethyl (2-(4-chlorophenyl)-1-methyl-3-
oxopyrazolidin-4-yl)phosphonate (8c). Yellow oil. Yield: 80%; IR
(film): 2981, 1694, 1587, 1485, 1348, 1249, 1018, 963; 1H NMR
isomer):
CH3CH2OP(O)), 16.3 (d,
CH3CH2CH2CH2), 27.3
d
13.9 (s, CH3CH2CH2CH2), 16.3 (d,
6.4 Hz, CH3CH2OP(O)), 22.3 (s,
CH3CH2CH2CH2), 36.6 (bs,
J
¼
5.1 Hz,
J
¼
(s,
(250 MHz, DMSO-d6, 100 ꢁC):
d
1.23 (t, J ¼ 7.0, 3H, (CH3CH2O)P(O)),
CH3CH2CH2CH2), 44.4 (bs, NeCH3), 49.0 (d, J ¼ 139.9 Hz, C-4), 62.4
(s, C-5), 63.5 (d, J ¼ 6.4 Hz, (CH3CH2O)2P(O)), 120.5 (s, 2ꢃ CeAr),
125.0 (s, CeAr),128.7 (s, 2ꢃ CeAr),137.0 (s, CeAr),164.5 (s, C-3); 31P
1.25 (t, J ¼ 7.0 Hz, 3H, (CH3CH2O)P(O)), 2.60 (s, 3H, CH3), 3.57 (dd,
J ¼ 13.4, 9.2, 2H, 2ꢃ H-5), 3.92 (dt, J ¼ 21.9, 9.2 Hz, 1H, H-4),
4.04e4.18 (m, 4H, (CH3CH2O)2P(O)), 7.49e7.62 (m, 4H, HeAr); 13C
NMR (101 MHz, CDCl3):
18H29N2O4P (C, H, N).
4.1.2.2.8. Diethyl (1-methyl-5-nonyl-3-oxo-2-phenylpyrazolidin-
d 20.19 (5%), 20.90 (95%). Anal.
NMR (62.9 MHz, DMSO-d6, 100 ꢁC):
d
15.4 (d,
J
¼
5.6,
C
(CH3CH2O)2P(O)), 40.3 (d, J ¼ 147.1, C-4), 42.8 (s, CH3), 51.6 (d, J ¼ 1.7,
C-5), 61.3 (d, J ¼ 6.7 Hz, (CH3CH2O)P(O)), 61.8 (d, J ¼ 6.5, (CH3CH2O)
P(O)),115.9 (s, CeAr),120.8 (s, 2ꢃ CeAr),131.1 (s, 2ꢃ CeAr),135.8 (s,
4-yl)phosphonate (13d). Yellow oil. Yield: 80%; IR (film): 3236,
2925, 2854, 1694, 1492, 1354, 1251, 1021, 965, 753, 692; 1H NMR

570
J. Modranka et al. / European Journal of Medicinal Chemistry 92 (2015) 565e574
(250 MHz, CDCl3, trans isomer):
d
0.88 (t, J ¼ 6.9 Hz, 3H, CH3(CH2)8),
J ¼ 218.4 Hz, C-4), 121.1 (s, 2ꢃ CeAr), 126.4 (s, CeAr), 128.8 (s,
1.17e1.77 (m, 22H, CH3(CH2)8, (CH3CH2O)2P(O)), 2.77 (s, 3H,
NeCH3), 2.90 (dd, J ¼ 3.0 Hz, 24.7 Hz, 1H, H-4), 3.42e3.58 (m, 1H, H-
5), 4.18e4.39 (m, 4H, (CH3CH2O)2P(O)), 7.10e7.20 (m, 1H, HeAr),
7.30e7.41 (m, 2H, HeAr), 7.70e7.77 (m, 2H, HeAr); 13C NMR
2ꢃ CeAr), 137.5 (s, CeAr), 149.3 (d, J ¼ 10.4 Hz, C-3), 159.1 (d,
J ¼ 23.2 Hz, C-5); 31P NMR (101 MHz, CDCl3):
d 18.85. Anal.
C
14H19N2O4P (C, H, N).
4.1.2.3.2. Diethyl (3-ethyl-5-hydroxy-1-phenyl-1H-pyrazol-4-yl)
phosphonate (11b). Red oil. Yield: 64%; IR (film): 2980, 1721, 1536,
1456, 1151, 1016, 967, 758, 573; 1H NMR (250 MHz, CDCl3):
1.30 (t,
(62.9 MHz, CDCl3, trans isomer):
d 14.0 (s, CH3(CH2)8), 16.3 (d,
J ¼ 6.1 Hz, (CH3CH2O)2P(O)), 22.6 (s, CH2), 25.2 (s, CH2), 29.2 (s,
2ꢃ CH2), 29.4 (s, 2ꢃ CH2), 31.8 (s, CH2), 36.7 (bs, CH2), 44.4 (bs,
NeCH3), 49.0 (d, J ¼ 138.3 Hz, C-4), 62.4 (s, C-5), 63.5 (d, J ¼ 6.7 Hz,
(CH3CH2O)2P(O)), 120.5 (s, 2ꢃ CeAr), 125.0 (s, CeAr), 128.7 (s,
2ꢃ CeAr), 137.0 (s, CeAr), 164.5 (d, J ¼ 2.7 Hz, C-3); 31P NMR
d
J ¼ 7.5 Hz, 3H, CH3CH2) 1.36 (t, J ¼ 7.1 Hz, 6H, (CH3CH2O)2P(O)), 2.64
(q, J ¼ 7.5 Hz, 2H, CH3CH2) 4.00e4.22 (m, 4H, (CH3CH2O)2P(O)),
7.24e7.32 (m, 1H, HeAr), 7.39e7.48 (m, 2H, HeAr), 7.75e7.82 (m,
2H, HeAr); 13C NMR (62.9 MHz, CDCl3):
d 12.5 (s, CH3CH2), 15.9 (d,
(101 MHz, CDCl3):
N).
d
21.14 (5%), 21.84 (95%). Anal. C23H39N2O4P (C, H,
J ¼ 7.0 Hz, (CH3CH2O)2P(O)), 21.8 (s, CH3CH2), 62.2 (d, J ¼ 4.6 Hz,
CH3CH2O)2P(O)), 82.7 (d, J ¼ 218.7 Hz, C-4),121.2 (s, 2ꢃ CeAr),126.3
(s, CeAr), 128.7 (s, 2ꢃ CeAr), 137.6 (s, CeAr), 154.6 (d, J ¼ 10.7 Hz, C-
4.1.2.2.9. Diethyl (1-methyl-3-oxo-2,5-diphenylpyrazolidin-4-yl)
phosphonate (13e). Yellow oil. Yield: 84%; IR (film): 3217, 2967,
2931, 1698, 1328, 1024, 965, 726, 665; 1H NMR (250 MHz, CDCl3):
3), 159.1 (d, J ¼ 23.2 Hz, C-5); 31P NMR (101 MHz, CDCl3):
d 18.71.
Anal. C15H21N2O4P (C, H, N).
d
1.31e1.44 (m, 6H, (CH3CH2OP)2(O)), 2.83 (s, 3H, NeCH3), 3.28 (dd,
4.1.2.3.3. Diethyl (3-butyl-5-hydroxy-1-phenyl-1H-pyrazol-4-yl)
phosphonate (11c). Brown oil. Yield: 72%; IR (film): 2959, 1718,
1537, 1455, 1151, 1017, 970, 758, 589; 1H NMR (250 MHz, CDCl3):
J ¼ 5.3 Hz, 23.4 Hz, 1H, H-4), 4.09e4.44 (m, 4H, (CH3CH2O)2P(O)),
4.63 (dd, J ¼ 5.1 Hz, 18.4 Hz, H-5), 7.17e7.53 (m, 8H, HeAr),
7.78e7.87 (m, 2H, HeAr); 13C NMR (176 MHz, CDCl3):
d
16.2 (d,
d
0.87 (t, J ¼ 7.3 Hz, 3H, CH3CH2CH2CH2), 1.15e1.42 (m, 8H,
J ¼ 6.4 Hz, CH3CH2OP(O)), 16.3 (d, J ¼ 6.4 Hz, CH3CH2OP(O)), 44.0
(bs, NeCH3), 51.5 (d, J ¼ 139.9 Hz, C-4), 62.6 (d, J ¼ 6.4 Hz,
CH3CH2OP(O)), 63.9 (d, J ¼ 6.4 Hz, CH3CH2OP(O)), 65.5 (s, C-5),
120.9 (s, 2ꢃ CeAr), 125.5 (s, CeAr), 126.0 (s, 2ꢃ CeAr), 127.9 (s,
CeAr), 128.8 (s, 2ꢃ CeAr), 128.9 (s, 2ꢃ CeAr), 136.5 (s, CeAr), 141.5
(bs, CeAr), 163.6 (d, J ¼ 2.5 Hz, C-3); 31P NMR (101 MHz, CDCl3):
CH3CH2CH2CH2, (CH3CH2O)2P(O)), 1.50e1.70 (m, 2H,
CH3CH2CH2CH2), 2.53 (t, J ¼ 8.1 Hz, 2H, CH3CH2CH2CH2)) 3.93e4.17
(m, 4H, (CH3CH2O)2P(O)), 7.15e7.24 (m, 1H, HeAr), 7.31e7.40 (m,
2H, HeAr), 7.66e7.73 (m, 2H, HeAr), 8.50 (bs, 1H, eOH); 13C NMR
(62.9 MHz, CDCl3):
(CH3CH2O)2P(O)),
d
13.7 (s, CH3CH2CH2CH2), 16.1 (d, J ¼ 7.0 Hz,
22.5 (s, CH3CH2CH2CH2), 28.3 (s,
d
21.21. Anal. C20H25N2O4P (C, H, N).
4.1.2.2.10. Diethyl [5-(4-methoxyphenyl)-1-methyl-3-oxo-2-
CH3CH2CH2CH2), 30.4 (s, CH3CH2CH2CH2), 62.4 (d, J ¼ 4.9 Hz,
CH3CH2O)2P(O)), 83.0 (d, J ¼ 219.3 Hz, C-4),121.5 (s, 2ꢃ CeAr),126.5
(s, CeAr), 128.9 (s, 2ꢃ CeAr), 137.6 (s, CeAr), 153.8 (d, J ¼ 10.7 Hz, C-
phenylpyrazolidin-4-yl]phosphonate (13f). Yellow oil. Yield: 51%;
IR (film): 3201, 2969, 1693, 1404, 1195, 1024, 965, 735, 647; 1H NMR
3), 159.1 (d, J ¼ 23.2 Hz, C-5); 31P NMR (101 MHz, CDCl3):
d 18.32.
(250 MHz, CDCl3):
d
1.34 (t, J ¼ 7.1 Hz, 3H, CH3CH2OP(O)), 1.38 (t,
Anal. C17H25N2O4P (C, H, N).
J ¼ 7.1 Hz, 3H, CH3CH2OP(O)), 2.78 (s, 3H, NeCH3), 3.28 (dd,
J ¼ 5.5 Hz, 23.9 Hz, 1H, H-4), 3.80 (s, 3H, CH3O), 4.14e4.24 (m, 2H,
CH3CH2OP(O)), 4.28e4.40 (m, 2H, CH3CH2OP(O)), 4.57 (dd,
J ¼ 5.7 Hz, 17.8 Hz, H-5), 6.86e6.93 (m, 2H, HeAr), 7.16e7.25 (m, 1H,
HeAr), 7.31e7.46 (m, 4H, HeAr), 7.75e7.82 (m, 2H, HeAr); 13C NMR
4.1.2.4. General procedure for the synthesis of 4-diethoxyphosphoryl-
1-phenylpyrazol-5-ols 11de11f. A mixture of ethyl 2-acyl-2-
diethoxyphosphorylacetate 10def (10 mmol), phenylhydrazine
(11 mmol), and AcOH (0.6 g, 20 mmol) was refluxed in H2O (50 mL)
for 3 h. The reaction mixture was cooled and extracted with EtOAc
(2 ꢃ 30 mL). The organic extracts were washed with brine, dried
over Na2SO4 and concentrated. The crude product was purified by
column chromatography (eluent: EtOAcehexane, 1:1).
(176 MHz, CDCl3):
d
16.2 (d, J ¼ 6.4 Hz, CH3CH2OP(O)), 16.3 (d,
J ¼ 6.4 Hz, CH3CH2OP(O)), 43.8 (bs, NeCH3), 51.3 (d, J ¼ 125.9 Hz, C-
4), 55.3 (s, CH3O), 62.6 (d, J ¼ 6.4 Hz, CH3CH2OP(O)), 63.8 (d,
J ¼ 6.4 Hz, CH3CH2OP(O)), 65.3 (s, C-5), 114.1 (s, 2ꢃ CeAr), 121.1 (s,
2ꢃ CeAr), 125.6 (s, CeAr), 127.4 (s, 2ꢃ CeAr), 128.9 (s, 2ꢃ CeAr),
131.5 (s, CeAr), 136.6 (s, CeAr), 159.3 (s, CeAr), 163.8 (d, J ¼ 5.1 Hz,
4.1.2.4.1. Diethyl (5-hydroxy-3-nonyl-1-phenyl-1H-pyrazol-4-yl)
phosphonate (11d). Orange oil. Yield: 72%; IR (film): 2922, 2851,
1624, 1500, 1455, 1179, 1018, 964, 757, 602; 1H NMR (250 MHz,
C-3); 31P NMR (101 MHz, CDCl3):
d 21.29. Anal. C21H27N2O5P (C, H,
N).
CDCl3):
CH3(CH2)6CH2CH2,
d
0.87 (t, J ¼ 6.9 Hz, 3H, CH3(CH2)8, 1.15e1.45 (m, 18H,
(CH3CH2O)2P(O)), 1.62e1.77 (m, 2H,
4.1.2.3. General procedure for the synthesis of 4-diethoxyphosphoryl-
1-phenylpyrazol-5-ols 11ae11c. To a suspension of 2-alkanoyl-2-
diethoxyphosphorylacetates 10aec (5 mmol) in water (20 mL)
phenylhydrazine hydrochloride (795 mg, 5.5 mmol) was added and
the resulting mixture was refluxed for 2 h. The reaction was cooled
and K2CO3 (1.38 g, 10 mmol) was added. Then the mixture was
refluxed for 2 h, cooled to room temperature and stirred overnight
at r.t. The resulting mixture was washed with Et2O, acidified to
pH ¼ 2 with 0.5 N HCl and extracted with EtOAc (3 ꢃ 20 mL). The
combined organic extracts were washed with brine, dried (Na2SO4)
and the solvent was evaporated. The resulting pyrazolols were used
in next step without further purification.
CH3(CH2)6CH2CH2), 2.56 (t, J ¼ 8.1 Hz, 2H, CH3(CH2)6CH2CH2)),
3.93e4.18 (m, 4H, (CH3CH2O)2P(O)), 7.12e7.21 (m, 1H, HeAr),
7.26e7.36 (m, 2H, HeAr), 7.65e7.77 (m, 2H, HeAr); 13C NMR
(62.9 MHz, CDCl3):
d
14.0 (s, CH3(CH2)8), 16.0 (d, J ¼ 6.7 Hz,
(CH3CH2O)2P(O)), 22.6 (s, CH2), 28.5 (s, CH2), 28.8 (s, CH2), 29.2 (s,
CH2), 29.4 (s, CH2), 29.45 (s, CH2), 29.5 (s, CH2), 31.8 (s, CH2), 62.1 (d,
J ¼ 3.4 Hz, CH3CH2O)2P(O)), 82.2 (d, J ¼ 220.8 Hz, C-4), 121.4 (s,
2ꢃ CeAr), 125.8 (s, CeAr), 128.6 (s, 2ꢃ CeAr), 138.2 (s, CeAr), 153.8
(d, J ¼ 11.9 Hz, C-3), 160.8 (d, J ¼ 21.6 Hz, C-5); 31P NMR (101 MHz,
CDCl3):
d 19.33. Anal. C22H35N2O4P (C, H, N).
4.1.2.4.2. Diethyl (5-hydroxy-1,3-diphenyl-1H-pyrazol-4-yl)phos-
phonate (11e). Orange oil. Yield: 75%; IR (film): 3270, 3052, 2985,
1736, 1600, 1481, 1249, 1023, 749, 689; 1H NMR (62.9 MHz, CDCl3):
4.1.2.3.1. Diethyl (5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)
phosphonate (11a). Red oil. Yield: 86%; IR (film): 2983, 1725, 1593,
d
1.20 (t, J ¼ 7.1 Hz, 6H, (CH3CH2O)2P(O)), 3.93e4.17 (m, 4H,
(CH3CH2O)2P(O)), 7.24e7.32 (m, 1H, HeAr), 7.36e7.48 (m, 5H,
HeAr), 7.85e7.94 (m, 4H, HeAr); 13C NMR (62.9 MHz, CDCl3):
16.0
1536, 1241, 1014, 975, 758, 576; 1H NMR (250 MHz, CDCl3):
d 1.36 (t,
J ¼ 7.1 Hz, 6H, (CH3CH2O)2P(O)), 2.28 (d, J ¼ 0.8 Hz, 3H, CH3)
3.96e4.24 (m, 4H, (CH3CH2O)2P(O)), 7.24e7.32 (m, 1H, HeAr),
7.38e7.48 (m, 2H, HeAr), 7.73e7.81 (m, 2H, HeAr); 13C NMR
d
(d, J ¼ 7.0 Hz, (CH3CH2O)2P(O)), 62.6 (d, J ¼ 4.3 Hz, CH3CH2O)2P(O)),
81.5 (d, J ¼ 216.2 Hz, C-4), 121.6 (s, 2ꢃ CeAr), 126.5 (s, CeAr), 127.4
(s, 2ꢃ CeAr), 128.2 (s, 2ꢃ CeAr), 128.6 (s, CeAr), 128.8 (s, 2ꢃ CeAr),
132.6 (s, CeAr), 138.0 (s, CeAr), 151.2 (d, J ¼ 10.1 Hz, C-3), 161.1 (d,
(62.9 MHz, CDCl3):
(CH3CH2O)2P(O)), 62.3 (d, J ¼ 4.6 Hz, CH3CH2O)2P(O)), 83.7 (d,
d
13.6 (s, CH3), 16.0 (d,
J
¼
7.0 Hz,

J. Modranka et al. / European Journal of Medicinal Chemistry 92 (2015) 565e574
571
J ¼ 30.5 Hz, C-5); 31P NMR (101 MHz, CDCl3):
d
19.41. Anal.
1.10e1.45 (m, 18H, CH3(CH2)6CH2CH2, (CH3CH2O)2P(O)), 1.55e1.70
(m, 2H, CH3(CH2)6CH2CH2), 2.93 (t, 8.3 Hz, 2H,
C
19H21N2O4P (C, H, N).
J
¼
4.1.2.4.3. Diethyl [5-hydroxy-3-(4-methoxyphenyl)-1-phenyl-1H-
CH3(CH2)6CH2CH2)), 3.21 (s, 3H, NeCH3), 4.03e4.25 (m, 4H,
(CH3CH2O)2P(O)), 7.18e7.32 (m, 3H, HeAr), 7.36e7.45 (m, 2H,
pyrazol-4-yl]phosphonate (11f). Red oil. Yield: 72%; IR (film): 3262,
2983, 1637, 1600, 1496, 1248, 1014, 972, 754, 692; 1H NMR
HeAr); 13C NMR (176 MHz, CDCl3):
d 13.8 (s, CH3(CH2)8), 16.1 (d,
(62.9 MHz, CDCl3):
d
1.22 (t, J ¼ 7.1 Hz, 6H, (CH3CH2O)2P(O)), 3.84 (s,
J ¼ 7.6 Hz, (CH3CH2O)2P(O)), 22.4 (s, CH2), 25.8 (s, CH2), 28.8 (s,
CH2), 29.0 (s, CH2), 29.1 (s, CH2), 29.2 (s, CH2), 29.3 (s, CH2), 31.6 (s,
CH2), 34.2 (s, NeCH3), 61.8 (d, J ¼ 6.4 Hz, CH3CH2O)2P(O)), 92.5 (d,
J ¼ 221.3 Hz, C-4), 125.5 (s, 2ꢃ CeAr), 127.6 (s, CeAr), 129.1 (s,
2ꢃ CeAr), 134.0 (s, CeAr), 163.6 (d, J ¼ 22.9 Hz, C-5), 164.0 (d,
3H, CH3O) 3.92e4.18 (m, 4H, (CH3CH2O)2P(O)), 6.93e6.98 (m, 3H,
HeAr), 7.27e7.47 (m, 3H, HeAr), 7.84e7.92 (m, 3H, HeAr); 13C NMR
(62.9 MHz, CDCl3):
d
15.8 (d, J ¼ 7.3 Hz, (CH3CH2O)2P(O)), 55.1 (s,
CH3O), 62.5 (d, J ¼ 3.7 Hz, CH3CH2O)2P(O)), 80.9 (d, J ¼ 215.6 Hz, C-
4), 113.5 (s, 2ꢃ CeAr), 121.4 (s, 2ꢃ CeAr), 125.2 (s, CeAr), 126.3 (s,
CeAr), 128.6 (s, 2ꢃ CeAr), 128.7 (s, 2ꢃ CeAr), 138.0 (s, CeAr), 150.9
(d, J ¼ 9.8 Hz, C-3), 159.9 (s, CeAr), 161.1 (d, J ¼ 23.2 Hz, C-5); 31P
J ¼ 14.0 Hz, C-3); 31P NMR (101 MHz, CDCl3):
d 13.29. Anal.
C23H37N2O4P (C, H, N).
4.1.2.5.5. Diethyl (1-methyl-3-oxo-2,5-diphenyl-2,3-dihydro-1H-
NMR (101 MHz, CDCl3):
d
19.62. Anal. C20H23N2O5P (C, H, N).
pyrazol-4-yl)phosphonate (12e). Yellow oil. Yield: 65%; IR (film):
2981, 1659, 1486, 1221, 1016, 947, 750, 583; 1H NMR (250 MHz,
4.1.2.5. General procedure for the synthesis of 4-diethoxyphosphoryl-
1-methyl-2-phenylpyrazol-3-ones 12aef. A solution of corre-
sponding pyrazolol 11aef (5 mmol) and methyl triflate (1.10 mL,
10 mmol) in 1,2-dichloroethane (20 mL) was heated in reaction
vessel at 80 ꢁC for 2 h. The solvent was evaporated and the crude
product was purified by column chromatography (eluent: EtOAc e
MeOH, 9:1).
4.1.2.5.1. Diethyl (1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-
pyrazol-4-yl)phosphonate (12a). Yellow oil. Yield: 61%; IR (film):
2979, 1665, 1537, 1486, 1232, 1024, 939, 760, 569; 1H NMR
CDCl3):
NeCH3), 4.00e4.18 (m, 4H, (CH3CH2O)2P(O)), 7.54e7.64 (m, 6H,
HeAr), 7.67e7.78 (m, 4H, HeAr); 13C NMR (176 MHz, CDCl3):
15.7
(d, 7.6 Hz, (CH3CH2O)2P(O)), 35.5 (s, NeCH3), 63.6 (s,
d
1.17 (t, J ¼ 6.9 Hz, 6H, (CH3CH2O)2P(O)), 3.46 (s, 3H,
d
J
¼
CH3CH2O)2P(O)), 91.0 (d, J ¼ 225.1 Hz, C-4), 125.6 (s, CeAr), 128.2 (s,
2ꢃ CeAr),128.9 (s, 2ꢃ CeAr),129.5 (s, 2ꢃ CeAr),130.0 (s, 2ꢃ CeAr),
130.2 (s, CeAr), 131.2 (s, CeAr), 131.5 (s, CeAr), 154.1 (d, J ¼ 12.7 Hz,
C-3), 161.5 (d, J ¼ 20.3 Hz, C-5); 31P NMR (101 MHz, CDCl3):
d 12.05.
Anal. C20H23N2O4P (C, H, N).
4.1.2.5.6. Diethyl [5-(4-methoxyphenyl)-1-methyl-3-oxo-2-
phenyl-2,3-dihydro-1H-pyrazol-4-yl]phosphonate (12f). Yellow oil.
Yield: 61%; IR (film): 2964, 1658, 1604, 1492, 1255, 1014, 792, 577;
(250 MHz, CDCl3):
d
1.28 (t, J ¼ 7.0 Hz, 6H, (CH3CH2O)2P(O)), 2.53 (d,
J ¼ 1.6 Hz, 3H, CH3), 3.21 (s, 3H, NeCH3), 4.05e4.20 (m, 4H,
(CH3CH2O)2P(O)), 7.21e7.33 (m, 3H, HeAr), 7.36e7.46 (m, 2H,
1H NMR (250 MHz, CDCl3):
(CH3CH2O)2P(O)), 3.00 (s, 3H, NeCH3), 3.80 (s, 3H, CH3O) 3.96e4.12
(m, 4H, (CH3CH2O)2P(O)), 6.92e7.02 (m, 2H, HeAr), 7.22e7.32 (m,
1H, HeAr), 7.32e7.56 (m, 6H, HeAr); 13C NMR (62.9 MHz, CDCl3):
d
1.14 (t,
J
¼
7.1 Hz, 6H,
HeAr); 13C NMR (62.9 MHz, CDCl3):
d
12.2 (s, CH3), 16.0 (d,
J ¼ 7.0 Hz, (CH3CH2O)2P(O)), 34.0 (s, NeCH3), 62.9 (d, J ¼ 5.2 Hz,
(CH3CH2O)2P(O)), 90.8 (d, J ¼ 224.8, C-4), 127.4 (s, 2ꢃ CeAr), 129.7
(s, 2ꢃ CeAr), 129.8 (s, CeAr), 131.9 (s, CeAr), 155.5 (d, J ¼ 18.9 Hz, C-
d
15.2 (d, J ¼ 7.0 Hz, (CH3CH2O)2P(O)), 36.8 (s, NeCH3), 54.4 (s,
5), 162.9 (d, J ¼ 13.1 Hz, C-3); 31P NMR (101 MHz, CDCl3):
d
13.41.
CH3O), 61.2 (d, J ¼ 5.8 Hz, CH3CH2O)2P(O)), 95.3 (d, J ¼ 221.7 Hz, C-
4), 113.0 (s, 2ꢃ CeAr), 119.2 (s, CeAr), 123.8 (s, 2ꢃ CeAr), 126.4 (s,
CeAr), 128.3 (s, 2ꢃ CeAr), 130.5 (s, 2ꢃ CeAr), 133.3 (s, CeAr), 160.7
(s, CeAr), 161.9 (d, J ¼ 18.3 Hz, C-5), 162.6 (d, J ¼ 14.9 Hz, C-3); 31P
Anal. C15H21N2O4P (C, H, N).
4.1.2.5.2. Diethyl (5-ethyl-1-methyl-3-oxo-2-phenyl-2,3-dihydro-
1H-pyrazol-4-yl)phosphonate (12b). Yellow oil. Yield: 60%; IR
(film): 2980, 1661, 1522, 1488, 1235, 1018, 957, 562; 1H NMR
NMR (101 MHz, CDCl3):
d 12.15. Anal. C21H25N2O5P (C, H, N).
(250 MHz, CDCl3):
d 1.13e1.32 (m, 9H, (CH3CH2O)2P(O), CH3CH2),
2.55 (q, J ¼ 7.5 Hz, 2H, CH3CH2), 3.23 (s, 3H, NeCH3), 3.97e4.17 (m,
4.1.2.6. Preparation of diethyl (3-oxo-1,2-diphenyl-2,3-dihydro-1H-
pyrazol-4-yl)phosphonate (16). A solution of 3-methoxy-2-
diethoxyphosphorylacrylate (15) (2.66 g, 10 mmol) and 1,2-
diphenylhydrazine (1.84 g, 10 mmol) in toluene (100 mL) was
heated in reaction vessel at 110 ꢁC for 80 h. Next, the mixture was
cooled and the solvent was evaporated. A crude product was pu-
rified by crystallization from Et2O e hexane, 1:1 to give 16 (83%) as
orange solid; mp 111e113 ꢁC; IR (film): 2976, 1670, 1548, 1492,
4H, (CH3CH2O)2P(O)), 7.15e7.33 (m, 2H, HeAr), 7.33e7.45 (m, 3H,
HeAr); 13C NMR (62.9 MHz, CDCl3):
d 13.0 (s, CH3CH2), 16.2 (d,
J ¼ 6.7 Hz, (CH3CH2O)2P(O)), 19.3 (s, CH3CH2), 34.0 (s, NeCH3), 62.0
(d, J ¼ 5.5 Hz, (CH3CH2O)2P(O)), 92.1 (d, J ¼ 220.2, C-4), 125.6 (s,
2ꢃ CeAr), 127.7 (s, CeAr), 129.2 (s, 2ꢃ CeAr), 133.9 (s, CeAr), 164.0
(d, J ¼ 13.7 Hz, C-3), 164.4 (d, J ¼ 21.9 Hz, C-5); 31P NMR (101 MHz,
CDCl3):
d 13.33. Anal. C16H23N2O4P (C, H, N).
4.1.2.5.3. Diethyl (5-butyl-1-methyl-3-oxo-2-phenyl-2,3-dihydro-
1H-pyrazol-4-yl)phosphonate (12c). Yellow oil. Yield: 57%; IR (film):
2929, 1659, 1523, 1490, 1233, 1018, 960, 799, 576; 1H NMR
1248, 1022, 971; 1H NMR (250 MHz, CDCl3):
d
1.30 (t, J ¼ 7.2, 6H,
(CH3CH2O)2P(O)), 4.10e4.25 (m, 4H, (CH3CH2O)2P(O)), 7.06e7.30
(m, 10H, HeAr), 8.10 (d, 1H, J ¼ 4.6, H-5); 13C NMR13C NMR
(250 MHz, CDCl3):
J ¼ 7.1 Hz, 6H, (CH3CH2O)2P(O)), 1.35e1.52 (m, 2H, CH3CH2CH2CH2),
1.54e1.69 (m, 2H, CH3CH2CH2CH2), 2.94 (t, 7.9 Hz, 2H,
d
0.92 (t, J ¼ 7.3 Hz, 3H, CH3CH2CH2CH2), 1.27 (t,
(176.0 MHz, CDCl3):
d
16.0 (d, J ¼ 6.8, (CH3CH2O)2P(O)), 62.2 (d,
J ¼ 5.6, (CH3CH2O)2P(O)), 97.2 (d, J ¼ 220.4, C-4), 121.2 (s, 2ꢃ CeAr),
123.9 (s, 2ꢃ CeAr), 126.8 (s, CeAr), 127.4 (s, CeAr), 128.7 (s,
2ꢃ CeAr), 129.6 (s, 2ꢃ CeAr), 134.3 (s, CeAr), 136.9 (s, CeAr), 148.8
(d, J ¼ 18.9, C-5), 163.6 (d, J ¼ 13.4, C-3); 31P NMR (101 MHz, CDCl3):
J
¼
CH3CH2CH2CH2), 3.21 (s, 3H, NeCH3), 4.04e4.18 (m, 4H,
(CH3CH2O)2P(O)), 7.19e7.32 (m, 2H, HeAr), 7.36e7.45 (m, 3H,
HeAr); 13C NMR (62.9 MHz, CDCl3):
d
13.6 (s, CH3CH2CH2CH2), 16.1
d 11.75. Anal. C19H21N2O4P (C, H, N).
(d, J ¼ 6.7 Hz, (CH3CH2O)2P(O)), 22.4 (s, CH3CH2CH2CH2), 25.6 (s,
CH3CH2CH2CH2), 30.8, (s, CH3CH2CH2CH2), 34.1 (s, NeCH3), 61.9 (d,
J ¼ 5.5 Hz, CH3CH2O)2P(O)), 92.4 (d, J ¼ 221.1 Hz, C-4), 125.6 (s,
2ꢃ CeAr), 127.7 (s, CeAr), 129.2 (s, 2ꢃ CeAr), 133.9 (s, CeAr), 163.4
(d, J ¼ 21.9 Hz, C-5), 164.1 (d, J ¼ 14.3 Hz, C-3); 31P NMR (101 MHz,
4.1.2.7. General procedure for the synthesis of 4-diethoxyphosphoryl-
1,2-diphenylpyrazolidin-3-ones 17aee. To a solution of the 4-
diethoxyphosphoryl-1,2-diphenylpyrazol-3-one 16 (745 mg,
2 mmol) in THF (15 mL) a solution of corresponding Grignard re-
agent (2.4 mmol) was added dropwise, under an argon atmosphere
at r.t., and the resulting mixture was refluxed for 2 h. After this time
the reaction mixture was quenched with H2O (5 mL), acidified to
pH ca. 3 with 10% aq HCl solution and extracted with CH2Cl2
(3 ꢃ 10 mL). The organic layer was dried over MgSO4 and the
CDCl3):
d 13.47. Anal. C18H27N2O4P (C, H, N).
4.1.2.5.4. Diethyl (1-methyl-5-nonyl-3-oxo-2-phenyl-2,3-
dihydro-1H-pyrazol-4-yl)phosphonate (12d). Yellow oil. Yield:
59%; IR (film): 2923, 2853, 1665, 1520, 1490, 1278, 1235, 1021, 961,
573; 1H NMR (250 MHz, CDCl3):
d
0.81 (t, J ¼ 6.5 Hz, 3H, CH3(CH2)8,

572
J. Modranka et al. / European Journal of Medicinal Chemistry 92 (2015) 565e574
solvent was evaporated. The crude product was purified by column
chromatography (eluent: CHCl3 e MeOH, 98:2).
4.1.2.7.1. Diethyl (5-methyl-3-oxo-1,2-diphenylpyrazolidin-4-yl)
phosphonate (17a). Yellow oil. Yield: 52%; IR (film): 2982, 1698,
1595, 1488, 1384, 1248, 1017, 946; 1H NMR (250 MHz, CDCl3, trans
16.3 (d, J ¼ 6.0, (CH3CH2O)P(O)), 41.3 (d, J ¼ 152.7, C-4), 55.9 (d,
J ¼ 2.3, C-5), 62.6 (d, J ¼ 6.4, (CH3CH2O)P(O)), 63.2 (d, J ¼ 6.6,
(CH3CH2O)P(O)), 118.3 (s, 2ꢃ CeAr), 118.5 (s, 2ꢃ CeAr), 123.9 (s,
CeAr), 124.7 (s, CeAr), 128.7 (d, J ¼ 7.1, CH]CH2), 128.8 (s,
2ꢃ CeAr), 129.1 (s, 2ꢃ CeAr), 129.3 (s, CH2), 137.8 (s, CeAr), 149.0 (s,
and cis isomers):
d
1.09 (t, J ¼ 7.1, 3H, (CH3CH2O)P(O)),1.36 (t, J ¼ 7.1,
CeAr), 166.6 (d, J ¼ 1.2, C-3); 31P NMR (101 MHz, CDCl3):
d 18.55
3H, (CH3CH2O)P(O)), 1.66 (d, J ¼ 6.7, 3H, CH3, 85%), 1.76 (d, J ¼ 5.7,
3H, CH3, 15%), 2.94 (dd, J ¼ 23.3, 2.8, 1H, H-4), 3.62e3.73 (m, 1H,
(CH3CHO)P(O)), 3.90e3.96 (m, 1H, (CH3CHO)P(O)), 4.11e4.38 (m,
2H, (CH3CH2O)P(O)), 4.49e4.60 (m, 1H, H-5), 6.93e7.03 (m, 2H,
HeAr), 7.11e7.40 (m, 6H, HeAr), 7.78e7.86 (m, 2H, HeAr); 13C NMR
(10%), 19.47 (90%).Anal. C21H25N2O4P (C, H, N).
4.1.2.7.5. Diethyl
phonate (17e). Yellow oil, Yield: 35%; IR (film): 2981, 1703, 1593,
1489, 1391, 1250, 1014, 964; 1H NMR (250 MHz, CDCl3):
1.07 (t,
(3-oxo-1,2,5-triphenylpyrazolidin-4-yl)phos-
d
J ¼ 7.1, 3H, (CH3CH2O)P(O)),1.30 (t, J ¼ 7.0, 3H, (CH3CH2O)P(O)), 3.30
(dd, J ¼ 23.4, 3.0, 1H, H-4), 3.67e3.84 (m, 1H, (CH3CHO)P(O)),
3.91e4.04 (m, 1H, (CH3CHO)P(O)), 4.08e4.22 (m, 2H, (CH3CH2O)
P(O)), 5.39 (dd, J ¼ 19.1, 2.9, 1H, H-5), 6.81e6.98 (m, 4H, HeAr),
7.10e7.24 (m, 4H, HeAr), 7.31e7.43 (m, 5H, HeAr), 7.50e7.53 (m,
2H, 2HeAr), 7.83e7.87 (m, 2H, HeAr); 13C NMR (62.9 MHz, CDCl3):
(62.9 MHz, CDCl3, trans isomer):
d
15.9 (d, J ¼ 5.3, (CH3CH2O)P(O)),
16.1 (d, J ¼ 6.1, (CH3CH2O)P(O)), 23.3 (d, J ¼ 13.4, CH3), 50.0 (d,
J ¼ 138.3, C-4), 61.6 (d, J ¼ 1.8, C-5), 62.5 (d, J ¼ 7.0, (CH3CH2O)P(O)),
62.9 (d, J ¼ 6.7, (CH3CH2O)P(O)), 117.3 (s, 2ꢃ CeAr), 119.0 (s,
2ꢃ CeAr), 122.7 (s, CeAr), 124.9 (s, CeAr), 128.6 (s, 2ꢃ CeAr), 128.7
(s, 2ꢃ CeAr), 138.3 (s, CeAr), 148.9 (s, CeAr), 165.5 (d, J ¼ 5.6, C-3);
d
15.9 (d, J ¼ 5.4, (CH3CH2O)P(O)), 16.1 (d, J ¼ 6.1, (CH3CH2O)P(O)),
31P NMR (101 MHz, CDCl3):
d
19.64 (15%), 19.73 (85%). Anal.
46.7 (d, J ¼ 137.2, C-4), 62.9 (d, J ¼ 6.9, (CH3CH2O)P(O)), 63.3 (d,
J ¼ 6.6, (CH3CH2O)P(O)), 68.6 (d, J ¼ 0.9, C-5), 115.3 (s, CeAr), 117.4
(s, 2ꢃ CeAr), 118.9 (s, 2ꢃ CeAr), 119.4 (s, CeAr), 123.1 (s, CeAr),
125.0 (s, CeAr), 125.2 (s, 2ꢃ 2ꢃ CeAr), 128.1 (s, CeAr), 128.7 (s,
2ꢃ CeAr), 128.9 (s, 2ꢃ CeAr), 129.1 (s, 2ꢃ CeAr), 129.2 (s, CeAr),
137.7 (s, CeAr), 142.1 (d, J ¼ 12.1, CeAr), 149.4 (s, CeAr), 156.8 (s,
C
20H25N2O4P (C, H, N).
4.1.2.7.2. Diethyl
(5-ethyl-3-oxo-1,2-diphenylpyrazolidin-4-yl)
phosphonate (17b). Yellow oil. Yield: 42%; IR (film): 2971, 1701,
1592, 1493, 1389, 1244, 1018, 955; 1H NMR (250 MHz, CDCl3, trans
isomer):
d
0.92 (t, J ¼ 7.1, 3H, CH3CH2), 1.18 (t, J ¼ 7.2, 3H, (CH3CH2O)
P(O)), 1.23 (t, J ¼ 7.1, 3H, (CH3CH2O)P(O)), 1.65e1.92 (m, 2H,
CH3CH2), 2.84 (dd, J ¼ 23.8, 1.8, 1H, H-4), 3.39e3.49 (m, 1H,
(CH3CHO)P(O)), 3.70e3.81 (m, 1H, (CH3CHO)P(O)), 3.98e4.13 (m,
2H, (CH3CH2O)P(O)), 4.16e4.29 (m, 1H, H-5), 6.79e6.92 (m, 2H,
HeAr), 7.02e7.28 (m, 6H, HeAr), 7.67e7.69 (m, 2H, HeAr); 13C NMR
CeAr), 164.6 (d, J ¼ 5.7, C-3); 31P NMR (101 MHz, CDCl3):
d 19.60,
Anal. C25H27N2O4P (C, H, N).
4 .1. 2 . 8 . G e n e r a l p r o c e d u r e f o r t h e s y n t h e s i s o f 4 -
methylidenepyrazolidin-3-ones 9aed, 14aef, 18aee. To a solution
of the corresponding pyrazolidinone 8aed, 13aef, 17aee (1 mmol)
in THF (10 mL), NaH (28 mg, 1.2 mmol) was added and the resulting
mixture was stirred at r.t. for 30 min. Then, paraformaldehyde
(150 mg, 5 mmol) was added in one portion. After 2 h the reaction
mixture was quenched with brine (5 mL), THF was evaporated and
the aqueous layer was extracted with CH2Cl2 (3 ꢃ 10 mL). The
organic layer was dried over MgSO4 and the solvent was evapo-
rated. The crude product was purified by column chromatography
(eluent: CH2Cl2).
(62.9 MHz, CDCl3, trans isomer):
d
10.3 (s, CH3), 15.8 (d, J ¼ 5.1,
(CH3CH2O)P(O)), 16.1 (d, J ¼ 6.0, (CH3CH2O)P(O)), 30.1 (d, J ¼ 13.7,
CH2), 48.9 (d, J ¼ 137.2, C-4), 62.4 (d, J ¼ 7.0, (CH3CH2O)P(O)), 62.9
(d, J ¼ 6.5, (CH3CH2O)P(O)), 67.2 (d, J ¼ 2.0, C-5), 116.8 (s, 2ꢃ CeAr),
118.8 (s, 2ꢃ CeAr), 122.2 (s, CeAr), 124.8 (s, CeAr), 128.5 (s,
2ꢃ CeAr), 129.2 (s, 2ꢃ CeAr), 138.4 (s, CeAr), 149.5 (s, CeAr), 165.8
(d, J ¼ 5.8, C-3); 31P NMR (101 MHz, CDCl3):
d 19.63 (10%), 19.76
(90%).Anal. C21H27N2O4P (C, H, N).
4.1.2.7.3. Diethyl
(5-butyl-3-oxo-1,2-diphenylpyrazolidin-4-yl)
phosphonate (17c). Yellow oil, Yield: 56%; IR (film): 2959, 1700,
4.1.2.8.1. 1-Methyl-4-methylene-2-phenylpyrazolidin-3-one (9a).
Yellow oil. Yield: 91%; IR (film): 2961, 2853, 1689, 1661, 1488, 1352,
1593, 1486, 1388, 1246, 1014, 955; 1H NMR (250 MHz, CDCl3, trans
isomer):
d
0.96 (t, J ¼ 7.3, 3H, CH3CH2), 0.98 (t, J ¼ 7.0, 3H,
754; 1H NMR (250 MHz, CDCl3):
d 2.59 (s, 3H, CH3), 3.52e3.87 (m,
(CH3CH2O)P(O)), 1.24 (t, J ¼ 7.0, 3H, (CH3CH2O)P(O)), 1.32e1.99 (m,
6H, CH3(CH2)3), 2.92 (dd, J ¼ 23.8, 1.7, 1H, H-4), 3.44e3.61 (m, 1H,
(CH3CHO)P(O)), 3.76e3.93 (m, 1H, (CH3CHO)P(O)), 4.00e4.22 (m,
2H, (CH3CH2O)P(O)), 4.25e4.39 (m, 1H, H-5), 6.84e6.94 (m, 3H,
HeAr), 7.07e7.21 (m, 3H, HeAr), 7.25e7.34 (m, 2H, HeAr),
7.71e7.75 (m, 2H, HeAr); 13C NMR (62.9 MHz, CDCl3, trans isomer):
1H, H-5), 4.07e4.39 (m, 1H, H-5), 5.53e5.55 (m, 1H, HeCH]),
6.18e6.21 (m, 1H, HeCH]), 7.12e7.20 (m, 1H, 1ꢃ HeAr), 7.34e7.42
(m, 2H, HeAr), 7.86e7.91 (m, 2H, HeAr); 13C NMR (62.9 MHz,
CDCl3):
d 45.7 (s, CH3), 56.3 (s, C-5), 117.5 (s, CH2]), 119.5 (s,
2ꢃ CeAr), 124.9 (s, CeAr), 128.8 (s, 2ꢃ CeAr), 137.2 (s, CeAr), 139.0
(s, C-4), 163.5 (s, C-3), ESI-MS: m/z 189.3 (Mþ1). C11H12N2O
(188.23). Anal. C11H12N2O (C, H, N).
d
13.9 (s, CH3), 15.9 (d, J ¼ 5.3, (CH3CH2O)P(O)), 16.1 (d, J ¼ 6.1,
(CH3CH2O)P(O)), 22.3 (s, CH2), 27.9 (s, CH2), 36.9 (d, J ¼ 13.4, CH2),
49.2 (d, J ¼ 136.9, C-4), 62.4 (d, J ¼ 7.0, (CH3CH2O)P(O)), 62.9 (d,
J ¼ 6.4, (CH3CH2O)P(O)), 66.1 (d, J ¼ 2.0, C-5), 116.8 (s, 2ꢃ CeAr),
118.8 (s, 2ꢃ CeAr), 122.2 (s, CeAr), 124.8 (s, CeAr), 128.6 (s,
2ꢃ CeAr), 128.8 (s, 2ꢃ CeAr), 138.5 (s, CeAr), 149.4 (s, CeAr), 165.9
4.1.2.8.2. 1-Methyl-4-methylene-2-(p-tolyl)pyrazolidin-3-one
(9b). Yellow oil. Yield: 68%; IR (film): 2960, 2858, 1693, 1662, 1492,
1348, 822; 1H NMR (250 MHz, CDCl3):
d 2.34 (s, 3H, CH3), 2.58 (s,
3H, CH3), 3.54e3.83 (m, 1H, 1ꢃ H-5), 4.10e4.37 (m, 1H, 1ꢃ H-5),
5.51e5.53 (m, 1H, HeCH]), 6.16e6.19 (m, 1H, HeCH]), 7.17e7.21
(m, 2H, HeAr), 7.73e7.77 (m, 2H, HeAr); 13C NMR (62.9 MHz,
(d, J ¼ 5.8, C-3); 31P NMR (101 MHz, CDCl3):
d 19.96 (5%), 20.05
(95%).Anal. C23H31N2O4P (C, H, N).
CDCl3): d 20.9 (s, CH3), 45.6 (s, CH3), 56.2 (s, C-5), 117.2 (s, CH2]),
4.1.2.7.4. Diethyl
(3-oxo-1,2-diphenyl-5-vinylpyrazolidin-4-yl)
119.7 (s, 2ꢃ CeAr), 129.4 (s, 2ꢃ 2ꢃ CeAr), 134.6 (s, CeAr), 134.7 (s,
CeAr), 139.0 (s, C-4), 163.2 (s, C-3). ESI-MS: m/z 203.3 (Mþ1), 225.3
(MþNa). C12H14N2O (202.25). Anal. C12H14N2O (C, H, N).
phosphonate (17d). Yellow oil, Yield: 83%; IR (film): 2960, 1698,
1591, 1492, 1388, 1244, 1012, 950; 1H NMR (250 MHz, CDCl3, trans
isomer):
d
1.05 (t, J ¼ 7.1, 3H, (CH3CH2O)P(O)), 1.29 (t, J ¼ 7.0, 3H,
4.1.2.8.3. 2-(4-Chlorophenyl)-1-methyl-4-methylenepyrazolidin-
3-one (9c). Yellow oil. Yield: 84%; IR (film): 2962, 2851, 1692, 1663,
(CH3CH2O)P(O)), 3.07 (dd, J ¼ 23.1, 2.8, 1H, H-4), 3.59e3.78 (m, 1H,
(CH3CHO)P(O)), 3.84e4.01 (m, 1H, (CH3CHO)P(O)), 4.05e4.29 (m,
2H, (CH3CH2O)P(O)), 4.80e4.90 (m, 1H, H-5), 5.31 (d, J ¼ 10.6, 1H,
HeCH]CH), 5.66 (d, J ¼ 16.9, 1H, HeCH]CH), 6.02 (ddd, J ¼ 16.9,
10.6, 5.2, 1H, CH2]CH), 6.87e6.99 (m, 3H, HeAr), 7.07e7.23 (m, 3H,
HeAr), 7.27e7.34 (m, 2H, HeAr), 7.74e7.79 (m, 2H, HeAr); 13C NMR
1485, 1344, 827; 1H NMR (250 MHz, CDCl3):
d 2.58 (s, 3H, CH3),
3.53e3.79 (m, 1H, H-5), 4.12e4.38 (m, 1H, H-5), 5.55e5.57 (m, 1H,
HeCH]), 6.19e6.21 (m, 1H, HeCH]), 7.32e7.36 (m, 2H, HeAr),
7.84e7.89 (m, 2H, HeAr); 13C NMR (62.9 MHz, CDCl3):
d 45.1 (s,
CH3), 55.7 (s, C-5), 117.6 (s, CH2]), 120.0 (s, 2ꢃ CeAr), 128.4 (s,
(62.9 MHz, CDCl3, trans isomer):
d
16.2 (d, J ¼ 5.0, (CH3CH2O)P(O)),
2ꢃ CeAr), 129.1 (s, CeAr), 135.5 (s, CeAr), 138.3 (s, C-4), 163.1 (s, C-

J. Modranka et al. / European Journal of Medicinal Chemistry 92 (2015) 565e574
573
3). ESI-MS: m/z 223.2 (Mþ1). C12H14ClN2O (222.67). Anal.
HeAr), 7.35e7.38 (m, 2H, HeAr), 7.39e7.44 (m, 4H, HeAr),
7.89e7.92 (m, 2H, HeAr); 13C NMR (176 MHz, CDCl3):
45.0 (s,
C
11H11ClN2O (C, H, N).
d
4.1.2.8.4. 2-(4-Bromophenyl)-1-methyl-4-methylenepyrazolidin-
NeCH3), 69.6 (s, C-5), 119.4 (s, CH2]), 120.2 (s, 2ꢃ CeAr), 124.3 (s,
CeAr), 125.3 (s, 2ꢃ CeAr), 126.8 (s, CeAr), 128.0 (s, CeAr), 128.7 (s,
2ꢃ CeAr), 128.9 (s, 2ꢃ CeAr), 137.2 (s, CeAr), 142.7 (s, C-4), 162.6 (s,
3-one (9d). Yellow oil. Yield: 61%; IR (film): 2960, 2855, 1689, 1661,
1506, 1349, 816; 1H NMR (250 MHz, CDCl3):
d
2.59 (s, 3H, CH3),
3.45e3.86 (m, 1H, H-5), 4.07e4.42 (m, 1H, H-5), 5.56e5.57 (m, 1H,
HeCH]), 6.20e6.22 (m, 1H, HeCH]), 7.47e7.51 (m, 2H, HeAr),
C-3). ESI-MS: m/z 265.3 (Mþ1).
C17H16N2O (264.13). Anal.
C17H16N2O (C, H, N).
7.79e7.83 (m, 2H, HeAr); 13C NMR (62.9 MHz, CDCl3):
d 45.4 (s,
4.1.2.8.10. 5-(4-Methoxyphenyl)-1-methyl-4-methylidene-2-
CH3), 55.9 (s, C-5), 117.2 (s, CH2]), 117.9 (s, CeAr), 120.5 (s,
2ꢃ CeAr), 131.5 (s, 2ꢃ CeAr), 136.1 (s, CeAr), 138.4 (s, C-4), 163.4 (s,
phenylpyrazolidin-3-one (14f). Yellow oil. Yield: 85%; IR (film):
2960, 2836, 1690, 1593, 1490, 1354, 1247, 1173, 1031, 756; 1H NMR
(700 MHz, CDCl3): d 2.71 (s, 3H, NeCH3), 3.81 (s, 3H, CH3O), 4.63 (m,
C-3). ESI-MS: m/z 267.2 (Mþ1).
C
11H11BrN2O (267.12). Anal.
C
11H11BrN2O (C, H, N).
4.1.2.8.5. 1,5-Dimethyl-4-methylidene-2-phenylpyrazolidin-3-one
(14a). Yellow oil. Yield: 72%; IR (film): 2970, 2865, 1691, 1661, 1492,
1354, 754; 1H NMR (250 MHz, CDCl3):
1H, H-5), 5.49 (d, J ¼ 2.2 Hz, 1H, HeCH]), 6.30 (d, J ¼ 2.4 Hz, 1H,
HeCH]), 6.88e6.91 (m, 2H, HeAr), 7.18e7.22 (m, 1H, HeAr),
7.30e7.34 (m, 2H, HeAr), 7.40e7.43 (m, 2H, HeAr), 7.86e7.89 (m,
d
1.35 (d, J ¼ 6.7 Hz, 3H, CH3),
2H, HeAr); 13C NMR (176 MHz, CDCl3):
d 44.9 (s, NeCH3), 55.3 (s,
2.57 (s, 3H, NeCH3), 3.73 (m, 1H, H-5), 5.48 (d, J ¼ 1.8 Hz, 1H,
HeCH]), 6.19 (d, J ¼ 2.1 Hz, 1H, HeCH]), 7.12e7.20 (m, 1H, HeAr),
7.34e7.43 (m, 2H, HeAr), 7.84e7.91 (m, 2H, HeAr); 13C NMR
CH3O), 69.3 (s, C-5), 114.1 (s, 2ꢃ CeAr), 119.2 (s, CH2]), 120.3 (s,
2ꢃ CeAr), 125.3 (s, 2ꢃ CeAr), 128.1 (s, 2ꢃ CeAr), 128.9 (s, 2ꢃ CeAr),
137.2 (s, CeAr), 142.9 (s, C-4), 159.4 (s, CeAr), 162.8 (s, C-3). ESI-MS:
m/z 295.2 (Mþ1). C18H18N2O2 (294.14). Anal. C18H18N2O2 (C, H, N).
4.1.2.8.11. 5-Methyl-4-methylene-1,2-diphenylpyrazolidin-3-one
(62.9 MHz, CDCl3): d 21.7 (s, CH3), 45.1 (s, NeCH3), 62.0 (s, C-5),117.5
(s, CH2]), 119.8 (s, 2ꢃ CeAr), 124.9 (s, CeAr), 128.8 (s, 2ꢃ CeAr),
137.6 (s, CeAr), 144.5 (s, C-4), 163.1 (s, C-3). ESI-MS: m/z 203.3
(Mþ1). C12H14N2O (202.11). Anal. C12H14N2O (C, H, N).
(18a). Yellow oil. Yield: 87%; IR (film): 2970, 2852,1697,1663,1488,
1
1346, 747; H NMR (250 MHz, CDCl3):
d
1.62 (d, J ¼ 6.9, CH3), 4.41
4.1.2.8.6. 5-Ethyl-1-methyl-4-methylidene-2-phenylpyrazolidin-
3-one (14b). Yellow oil. Yield: 61%; IR (film): 2961, 2872,1691,1660,
(qdd, J ¼ 6.9, 1.9, 1.2 Hz, 1H, H-5), 5.46 (d, J ¼ 1.2, 1H, HeCH]), 6.22
(d, J ¼ 1.9, 1H, HeCH]), 7.01e7.15 (m, 4H, HeAr), 7.29e7.40 (m, 4H,
1492, 1355, 753, 692; 1H NMR (250 MHz, CDCl3):
d
1.02 (d,
HeAr), 7.92e7.96 (m, 2H, HeAr); 13C NMR (62.9 MHz, CDCl3):
d 23.4
J ¼ 7.3 Hz, 3H CH3CH2), 1.48e1.75 (m, 2H, CH3CH2), 2.60 (s, 3H,
NeCH3), 3.51 (bt, J ¼ 6.5 Hz, 1H, H-5), 5.49 (d, J ¼ 1.6 Hz, 1H,
HeCH]), 6.22 (d, J ¼ 1.9 Hz, 1H, HeCH]), 7.12e7.20 (m, 1H, HeAr),
7.35e7.43 (m, 2H, HeAr), 7.88e7.94 (m, 2H, HeAr); 13C NMR
(s, CH3), 66.1 (s, C-5), 118.0 (s, CH2]), 118.7 (s, 2ꢃ CeAr), 118.8 (s,
2ꢃ CeAr), 124.2 (s, CeAr), 124.8 (s, CeAr), 128.8 (s, 2ꢃ CeAr), 129.2
(s, 2ꢃ CeAr), 138.7 (s, C-4), 143.5 (s, CeAr), 150.7 (s, CeAr), 164.1 (s,
C-3). ESI-MS: m/z 265.3 (Mþ1), 287.3 (MþNa). C17H16N2O (264.32).
Anal. C17H16N2O (C, H, N).
(176 MHz, CDCl3):
d 9.7 (s, CH3CH2), 29.3 (s, CH3CH2), 45.8 (s,
NeCH3), 67.8 (s, C-5), 118.3 (s, CH2]), 119.5 (s, 2ꢃ CeAr), 124.7 (s,
CeAr), 128.8 (s, 2ꢃ CeAr), 137.7 (s, CeAr), 143.2 (s, C-4), 163.4 (s, C-
3). ESI-MS: m/z 217.2 (Mþ1). C13H16N2O (216.13). Anal. C13H16N2O
(C, H, N).
4.1.2.8.12. 5-Ethyl-4-methylene-1,2-diphenylpyrazolidin-3-one
(18b). Yellow oil. Yield: 92%; IR (film): 2972, 2849, 1696, 1663,
1486, 1349, 747; 1H NMR (250 MHz, CDCl3):
d
1.49 (t, J ¼ 7.3, 3H,
CH3CH2), 1.95e2.24 (m, 2H, CH3CH2), 4.40e4.47 (m, 1H, H-5), 5.69
(d, J ¼ 1.4, 1H, HeCH]), 6.47 (d, J ¼ 1.7, 1H, HeCH]), 7.23e7.40 (m,
4H, HeAr), 7.42e7.62 (m, 4H, HeAr), 8.16e8.20 (m, 2H, HeAr); 13C
4.1.2.8.7. 5-Butyl-1-methyl-4-methylidene-2-phenylpyrazolidin-
3-one (14c). Yellow oil. Yield: 58%; IR (film): 2927, 2857,1693,1492,
1355, 753, 692; 1H NMR (250 MHz, CDCl3):
d
0.91 (d, J ¼ 7.2 Hz, 3H,
NMR (62.9 MHz, CDCl3): d 10.2 (s, CH3), 30.1 (s, CH2), 72.0 (s, C-5),
CH3(CH2)3, 1.24e1.73 (m, 6H, CH3(CH2)3), 2.59 (s, 3H, NeCH3),
3.50e3.61 (m, 1H, H-5), 5.49 (d, J ¼ 1.6 Hz, 1H, HeCH]), 6.21 (d,
J ¼ 1.9 Hz, 1H, HeCH]), 7.11e7.20 (m, 1H, HeAr), 7.34e7.44 (m, 2H,
118.2 (s, CH2]), 118.4 (s, 2ꢃ CeAr), 118.5 (s, 2ꢃ CeAr), 123.9 (s,
CeAr), 124.6 (s, CeAr), 128.7 (s, 2ꢃ CeAr), 129.2 (s, 2ꢃ CeAr), 138.6
(s, C-4), 142.2 (s, CeAr), 150.9 (s, CeAr), 164.6 (s, C-3). ESI-MS: m/z
279.3 (Mþ1). C18H18N2O (278.35). Anal. C18H18N2O (C, H, N).
4.1.2.8.13. 5-Butyl-4-methylene-1,2-diphenylpyrazolidin-3-one
(18c). Yellow oil. Yield: 92%; IR (film): 2977, 2847, 1689, 1660, 1488,
HeAr), 7.88e7.94 (m, 2H, HeAr); 13C NMR (176 MHz, CDCl3):
d 14.0
(s, CH3(CH2)3), 22.5 (s, CH2), 27.5 (s, CH2), 36.0 (s, CH2), 45.8 (s,
NeCH3), 66.6 (s, C-5), 118.2 (s, CH2]), 119.5 (s, 2ꢃ CeAr), 124.8 (s,
CeAr), 128.8 (s, 2ꢃ CeAr), 137.8 (s, CeAr), 143.6 (s, C-4), 163.5 (s, C-
3). ESI-MS: m/z 245.2 (Mþ1). C15H20N2O (244.16). Anal. C15H20N2O
(C, H, N).
1343, 745; 1H NMR (250 MHz, CDCl3):
1.41e2.02 (m, 6H, CH3(CH2)3), 4.23e4.29 (m, 1H, H-5), 5.45 (d,
J ¼ 1.4, 1H, HeCH]), 6.22 (d, J ¼ 1.7 Hz, 1H, HeCH]), 6.99e7.18 (m,
4H, HeAr), 7.26e7.40 (m, 4H, HeAr), 7.93e7.97 (m, 2H, HeAr); 13C
d
1.01 (t, J ¼ 7.2, 3H, CH3CH2),
4.1.2.8.8. 1-Methyl-4-methylidene-5-nonyl-2-phenylpyrazolidin-
3-one (14d). Yellow oil. Yield: 75%; IR (film): 2923, 2853, 1694,
NMR (62.9 MHz, CDCl3):
d 13.9 (s, CH3), 22.4 (s, CH2), 27.8 (s, CH2),
1492, 1354, 754, 691; 1H NMR (700 MHz, CDCl3):
d
0.89 (t,
36.6 (s, CH2), 70.8 (s, C-5), 118.3 (s, CH2]), 118.4 (s, 2ꢃ CeAr), 118.5
(s, 2ꢃ CeAr), 123.9 (s, CeAr), 124.6 (s, CeAr), 128.7 (s, 2ꢃ CeAr),
129.2 (s, 2ꢃ CeAr), 138.6 (s, C-4), 142.4 (s, CeAr), 150.8 (s, CeAr),
164.6 (s, C-3). ESI-MS: m/z 307.4 (Mþ1). C20H22N2O (306.40). Anal.
J ¼ 6.6 Hz, CH3), 1.23e1.36 (m, 12H, CH3(CH2)6CH2CH2), 1.42e1.55
(m, 3H, CH3(CH2)6CH2CH2)), 1.64e1.71 (m, 1H, CH3(CH2)6CH2CH2)),
2.60 (s, 3H, NeCH3), 3.58 (m, 1H, H-5), 5.49 (d, J ¼ 1.8 Hz, 1H,
HeCH]), 6.19 (d, J ¼ 1.8 Hz, 1H, HeCH]), 7.14e7.18 (m, 1H, HeAr),
7.37e7.41 (m, 2H, HeAr), 7.90e7.93 (m, 2H, HeAr); 13C NMR
C20H22N2O (C, H, N).
4.1.2.8.14. 4-Methylene-1,2-diphenyl-5-vinylpyrazolidin-3-one
(176 MHz, CDCl3):
d
14.0 (s, CH3), 22.6 (s, CH2), 25.2 (s, CH2), 29.2 (s,
(18d). Yellow oil. Yield: 85%; IR (film): 2978, 2846,1692,1664,1493,
CH2), 29.3 (s, CH2), 29.4 (s, CH2), 29.43(s, CH2), 31.8 (s, CH2), 36.2 (s,
CH2), 45.7 (s, NeCH3), 66.5 (s, C-5), 118.1 (s, CH2]), 119.4 (s,
2ꢃ CeAr), 124.7 (s, CeAr), 128.8 (s, 2ꢃ CeAr), 137.7 (s, CeAr), 143.5
(s, C-4), 163.4 (s, C-3). ESI-MS: m/z 315.3 (Mþ1). C20H30N2O
(314.24). Anal. C20H30N2O (C, H, N).
1340, 749; 1H NMR (250 MHz, CDCl3):
d
4.70 (ddd, J ¼ 5.2, 1.7, 1.4,
1H, H-5), 5.21 (ddd, J ¼ 10.1,1.7,1.2, 1H, HeCH]CH), 5.40 (d, J ¼ 1.4,
1H, HeCH]), 5.46 (ddd, J ¼ 16.9,1.4,1.2, 1H, HeCH]CH), 5.93 (ddd,
J ¼ 16.9, 10.1, 5.2, 1H, CH2]CH), 6.20 (d, J ¼ 1.7, 1H, HeCH]),
6.91e7.05 (m, 4H, HeAr), 7.14e7.27 (m, 4H, HeAr), 7.81e7.84 (m,
4.1.2.8.9. 1-Methyl-4-methylidene-2,5-diphenylpyrazolidin-3-one
(14e). Yellow oil. Yield: 63%; IR (film): 3063, 2863,1690,1660,1593,
2H, HeAr); 13C NMR (62.9 MHz, CDCl3):
d 59.5 (s, C-5),117.7 (s, CH2),
118.4 (s, CH2), 118.5 (s, 2ꢃ CeAr), 118.8 (s, 2ꢃ CeAr), 124.0 (s, CeAr),
124.6 (s, CeAr),128.8 (s, 2ꢃ CeAr),129.2 (s, 2ꢃ CeAr),137.9 (s, CH]
CH2), 138.3 (s, C-4), 151.0 (s, 2ꢃ CeAr), 164.6 (s, C-3). ESI-MS: m/z
277.3 (Mþ1). C18H16N2O (276.33). Anal. C18H16N2O (C, H, N).
1489, 1355, 753, 692; 1H NMR (700 MHz, CDCl3):
d 2.74 (s, 3H,
NeCH3), 4.69 (bs, 1H, H-5), 5.53 (d, J ¼ 2.2 Hz, 1H, HeCH]), 6.31 (d,
J ¼ 2.4 Hz, 1H, HeCH]), 7.19e7.22 (m, 1H, HeAr), 7.30e7.33 (m, 1H,

574
J. Modranka et al. / European Journal of Medicinal Chemistry 92 (2015) 565e574
butyrolactones: new synthetic approaches, Angew. Chem. Int. Ed. 48 (2009)
9426e9452.
4.1.2.8.15. 4-Methylene-1,2,5-triphenylpyrazolidin-3-one
Yellow oil. Yield: 89%; IR (film): 3029, 2917, 1696, 1660, 1487, 1352,
750; 1H NMR (250 MHz, CDCl3):
(18e).
[2] A. Albrecht, Ł. Albrecht, T. Janecki, Recent advances in the synthesis of
a-
d
5.29 (dd, J ¼ 2.0,1.7,1H, H-5), 5.55
alkylidene-substituted d-lactones, g-lactams and d-lactams, Eur. J. Org. Chem.
15 (2011) 2747e2766.
[3] S. Zhang, Y.-K. Won, C.-N. Ong, H.-M. Shen, Anti-cancer potential of sesqui-
terpene lactones: bioactivity and molecular mechanisms, Curr. Med. Chem.
Anti Cancer Agents 5 (2005) 239e249.
(d, J ¼ 1.7, 1H, HeCH]), 6.31 (d, J ¼ 2.0, 1H, HeCH]), 7.01e7.14 (m,
4H, HeAr), 7.22e7.43 (m, 7H, HeAr), 7.48e7.52 (m, 2H, HeAr),
7.92e7.96 (m, 2H, HeAr); 13C NMR (62.9 MHz, CDCl3):
d 72.7 (s, C-
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CeAr), 124.4 (s, CeAr), 124.9 (s, CeAr), 126.1 (s, 2ꢃ CeAr), 128.1 (s,
CeAr), 128.9 (s, 2ꢃ CeAr), 129.0 (s, CeAr), 129.3 (s, 2ꢃ CeAr), 138.2
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Novel synthesis, cytotoxic evaluation, and structureꢂactivity relationship
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drial reduction assay on two leukemia cell lines, promyelocytic HL-
60 and lymphoblastic NALM-6 and on one solid tumor-derived cell
line, breast cancer MCF-7 adenocarcinoma. Cells were purchased
from the European Collection of Cell Cultures (ECACC). Leukemia
cells were cultured in RPMI 1640 medium, while MCF-7 cells in
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with 10% heat-inactivated fetal bovine serum (Invitrogen, Paisley,
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and all reagents for cell culture were purchased from Cascade Bi-
ologics (Portland, Oregon, USA). The HUVECs were cultured ac-
cording to the manufacturer's instructions and the cells underwent
3e8 passages. Cells were grown in 37 ꢁC in a humidified atmo-
sphere of 5% CO2 in air. Exponentially growing cells were seeded at
8 ꢃ 103/well on 96-well plates (Nunc, Roskilde, Denmark). After
24 h, the tested compounds (freshly prepared in DMSO and diluted
with complete culture medium to obtain the concentration range
from 10ꢂ7 to 10ꢂ3 M) were added and the plates were incubated for
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U. Krajewska, A. Janecka, A. Wyre˛bska, B. Rozalska, T. Janecki, Synthesis and
biological evaluation of a-methylidene-d-lactones with 3,4-dihydrocoumarin
skeleton, Bioorg. Med. Chem. 20 (2012) 5017e5026.
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Methylideneisoxazolidin-5-ones e a new class of
a-methylidene-g-lactones
with high cytostatic activity, Bioorg. Med. Chem. Lett. 16 (2006) 1430e1433.
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isopropyl-2-methyl-4-methyleneisoxazolidin-5-one (MZ-6)
e a new com-
48
h.
Afterwards,
3-(4,5-dimethylthiazol-2-yl)-2,5-
pound with -methylene- -lactone motif e on two breast cancer cell lines,
a
g
Chem. Biol. Drug Des. 79 (2012) 112e120.
[15] A. Wyre˛bska, J. Szymanski, K. Gach, J. Piekielna, J. Koszuk, T. Janecki,
diphenyltetrazolium bromide (MTT, 5 mg/mL in PBS) was added
and incubation was continued for 2 h. The metabolically active cells
reduced MTT to blue formazan crystals. Then, the MTT-containing
ꢀ
A. Janecka, Apoptosis-mediated cytotoxic effects of parthenolide and the new
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(2013) 1655e1663.
medium was carefully aspirated and 100 mL DMSO was added to
ꢀ
[16] C. Belaud, C. Roussakis, Y. Letourneux, N.E. Alami, J. Villieras, Synthesis of
dissolve the crystals. After shaking 10 min in the dark absorbance
was read at 560 nm on an ELISAeplate reader (ELX 800, Bio-Tek,
USA) and compared with control (untreated cells). The IC50 values
were calculated from concentrationeresponse curves.
potential cytotoxic
a-methylene g-lactams, Synth. Commun. 15 (1985)
1233e1243.
[17] T.G. Elford, D.G. Hall, Imine allylation using 2-alkoxycarbonyl allylboronates
as an expedient three-component reaction to polysubstituted -exo-methy-
lene- -lactams, Tetrahedron Lett. 49 (2008) 6995e6998.
[18] J. Modranka, R. Jakubowski, T. Janecki, Versatile synthesis of 4-
methylidenepyrazolidin-3-ones using Horner-Wadsworth-Emmons
approach, Synlett 25 (2014) 105e109.
a
g
Acknowledgments
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[19] P.C. Miller, J.M. Molyneaux, “One-pot” synthesis of dimethyl [1-substituted-5-
hydroxy-1H-pyrazol-4-yl]phosphonates, Org. Prep. Proced. Int. 31 (1999)
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This work was financed by the Ministry of Science and Higher
Education (Project No. N N204 005736).
[20] T. Janecki, A. Albrecht, J. Koszuk, J. Modranka, D. Słowak, A simple and
effective synthesis of activated vinylphosphonates from 3-methoxy-2-dieth-
oxyphosphorylacrylate, Tetrahedron Lett. 51 (2010) 2274e2276.
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drugs, Chem. Rev. 99 (1999) 2451e2466.
Appendix A. Supplementary data
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.ejmech.2015.01.029.
[22] H. Krawczyk, Ł. Albrecht, J. Wojciechowski, W.M. Wolf, U. Krajewska,
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M. Rozalski, A convenient synthesis and cytotoxic evaluation of N-unsub-
stituted a-methylene-g-lactams,, Tetrahedron 64 (2008) 6307e6314.
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