The synthesis of new acyclic analogs of 3-phenacyluridine and comparative evaluation of their in vivo biological activity

Article abstract of DOI:10.1007/s10593-020-02729-x

[Figure not available: see fulltext.] New structural analogs of 3-phenacyluridine were obtained as a result of N(3)-alkylation of 1-(2-acetoxyethyl)- and 1-(2-acetoxyethoxymethyl) uracil. Biological studies of the title compounds in an acute in vivo experiment did not reveal their hypnotic properties and ability to enhance the effects of diazepam and chloral hydrate.

Full text of DOI:10.1007/s10593-020-02729-x

DOI 10.1007/s10593-020-02729-x
Chemistry of Heterocyclic Compounds 2020, 56(6), 769–775
The synthesis of new acyclic analogs of 3-phenacyluridine
and comparative evaluation of their in vivo biological activity
Ivan А. Novakov1, Leila L. Brunilina1, Ivan А. Kirillov1*, Maxim B. Nawrozkij1,
Mariya D. Robinovich1,2, Evgeniya S. Titova1, Dmitry S. Sheikin1, Evsey А. Ruchko3,
Alla V. Pavlova4, Anastasiya А. Kotlyarova4, Tatyana G. Tolstikova4
1 Volgograd State Technical University,
28 Lenina Ave., Volgograd 400005, Russia; e-mail: kirillow.vania@yandex.ru
2 JSC ''Volzhsky Orgsinthese'',
100 Aleksandrova St., Volzhskiy 404117, Russia; e-mail: robinovich.m@yandex.ru
3 JSC ''Pharm-Sintez'',
2, Build. 46 2nd Kabelnaya St., Moscow 111024, Russia; e-mail: evsevius@mail.ru
4 N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences,
9 Akademika Lavrentieva Ave., Novosibirsk 630090, Russia;
e-mail: tg_tolstikova@mail.ru
Translated from Khimiya Geterotsiklicheskikh Soedinenii,
2020, 56(6), 769–775
Submitted February 22, 2020
Accepted after revision April 16, 2020
New structural analogs of 3-phenacyluridine were obtained as a result of N(3)-alkylation of 1-(2-acetoxyethyl)- and 1-(2-acet-
oxyethoxymethyl)uracil. Biological studies of the title compounds in an acute in vivo experiment did not reveal their hypnotic properties
and ability to enhance the effects of diazepam and chloral hydrate.
Keywords: 3-phenacyluridine, alkylation, biological activity, hypnotics, uridine receptor.
The search for new sleeping pills that are not addictive
is an important area of medicinal chemistry. As promising
hypnotics that can compete with the traditionally used
derivatives of barbituric acid, 1,4-benzodiazepine, or
Z-drugs, a number of compounds with different structure
and mechanism of action are considered,1 including
derivatives of the natural nucleoside uridine.
Data on the hypnotic effects of 3-phenacyluridine (Fig. 1)
upon intracerebral administration were first published in
1994.2 For a long time, the question of the biomolecular
mechanism of action of 3-phenacyluridine, which has a
structure different from other known hypnotics, remained
open. When studying its effect on benzodiazepine
receptors, an insignificant affinity for them was
discovered,3 and only a few years later it was found that the
affinity of this compound for specific CNS uridine
receptors determine its hypnotic properties.4 It was shown
that the metabolic reduction product of the keto group of
3-phenacyluridine also has an affinity for these receptors,
and the S-isomer exceeds the R-isomer of the correspond-
ing alcohol by 187 times in affinity for uridine receptors
and 15 times in duration of hypnotic action.5 As a result of
the study, it was established that the formed alcohols are
pharmacologically active metabolites of the starting
ketone.6
In the course of studying the structure–activity
relationship, it was shown that the replacement of D-ribose
fragment with 2-deoxy-D-ribose or uracil fragment with
6-azauracil fragment7 in the structure of the prototype
substance leads to a sharp decrease in hypnotic activity.
Figure 1. Structures of known hypnotics.
0009-3122/20/56(6)-0769©2020 Springer Science+Business Media, LLC
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Chemistry of Heterocyclic Compounds 2020, 56(6), 769–775
Scheme 1
However, some hypnotic activity was retained in deri-
vatives of 2'-deoxy-2'-fluoro-3-phenacyluridine, although
they showed more antiviral activity against HIV-1.8
Analogs of 3-phenacyluridine, in the structure of which the
glycosyl fragment is replaced by heteroarylmethyl moiety,
have pronounced hypnotic effect, which also enhance the
action of pentobarbital and diazepam under the conditions
of an acute experiment.9 It is known from literature that
3-phenacyluridine derivatives containing one or more MeO
groups in the benzene ring have an antinociceptive
of a catalytic amount of trimethylsilyl chloride (TMSCl)
led to the formation of 2,4-bis[(trimethylsilyl)oxy]-
pyrimidine (2). As a result of the subsequent alkylation of
pyrimidine 2 with 2-(bromomethoxy)ethyl acetate in
MeCN at room temperature17 or 2-bromoethyl acetate at
160–180°С in neat,18 the corresponding 1-[(2-hydroxy-
ethoxy)methyl]- and 1-(2-hydroxyethyl)uracil acetates 3, 4
were isolated after hydrolysis and chromatographic
purification. Then, the obtained compounds 3, 4 were
subjected to N(3)-alkylation using phenacyl halides,
α-bromopropiophenones, or (chloromethyl)(4-fluorophenyl)-
sulfane in the presence of K2CO3.
activity.10
The
corresponding
3-benzyl-substituted
derivatives of uridine, for which hypnotic activity upon
intracerebral administration has been established,11 do not
show hypnotic properties with other routes of
administration. This is probably due to their high
hydrophilicity and low ability to cross the blood-brain
barrier. At the same time, their analogs, in which the hydroxy
groups of the ribose fragment are methylated or acylated,
retain their activity when administered intravenously.12
Replacing the ribose fragment with a hydrocarbon
substituent results in compounds exhibiting hypnotic pro-
perties upon intraperitoneal administration, equal in activity
and toxicity to barbital.13 In contrast to the derivatives of
6-aza-3-phenacyluridine and 3-phenacylthymidine,7 the cor-
responding derivatives of 6-aza-3-benzyluracil14 and 3-benzyl-
thymine15 exhibit hypnotic activity and enhance the action
of pentobarbital. Similar biological properties are also charac-
teristic of arabinosides of 3-benzyluracil derivatives.16
Based on the data described above, the objective of our
study was to obtain compounds with both high hypnotic
activity of 3-phenacyluridine and lipophilicity of 1-alkyl-
3-benzyluracils. The purpose of the work was to create a
potential sleeping pill effective when administered per os
and acting on the uridine receptor system of CNS. Thus,
we obtained and studied in vivo analogs of 3-phenacyl-
uridine containing a bioisostere acyclic fragment at
position 1 of the pyrimidine ring (Scheme 1).
It should be noted that the reaction proceeds
regioselectively. When using phenacyl bromides, stirring at
room temperature in anhydrous DMF was sufficient, while
heating under reflux in anhydrous MeCN was necessary
employing the rest of the alkylating agents with lower
reactivity. The obtained compounds, with the exception of
product 7, were viscous syrups, the purification of which
was difficult and was carried out in two stages: column
chromatography followed by preparative HPLC.
The results of the study of the biological activity of
compounds 5, 8, 11 in the open field test after a single
intragastric administration are presented in Table 1.
Compound 11 at a dose of 10 mg/kg during intragastric
administration significantly reduced vertical activity and
the number of racks, which indicates the possible hypnotic
effect of target compound 11 on the animal's body.
To confirm our assumption, the next step was the
open field test for compound 11 with intraperitoneal and
intragastric administration at a dose of 50 mg/kg. Thus,
with intragastric administration, compound 11 does not
exert a depressing effect on the indications of vertical
activity, as with intraperitoneal administration, but on the
contrary, its increase relative to intact control was recorded
(Table 2). Perhaps this reverse reaction of increasing
the amount of vertical activity is associated with a dose-
dependent manifestation of side effects. Such
a
To access the target substances 5–11, uracil (1) was used
as the starting compound, silylation of which in
hexamethyldisilazane (HMDS) under reflux in the presence
phenomenon has been described for some groups of
tranquilizers, including uridine.19
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Chemistry of Heterocyclic Compounds 2020, 56(6), 769–775
Table 1. The effect of compounds 5, 8, 11 on the locomotor response of animals
in the open field test after a single intragastric administration at a dose of 10 mg/kg (n = 8, duration 2 min)*
Level of reliability in comparison
with intact control
Compound
Intact
control
Test indicators
Compound
5
8
11
5
8
11
Total locomotor activity,
78.25 8.35
75.43 7.11 84.25 3.58
84.25 3.58
0.54
0.96
0.16
number of locomotor acts
Locomotor activity, s
79.84 3.73
40.16 3.73
79.89 3.40 83.71↑ 2.89
40.11 3.40 36.29↓ 2.89
77.09 4.40
42.91 4.40
0.96
0.96
0.07
0.05
0.54
0.87
0.34
0.03
0.09
0.03
0.03
0.15
0.15
0.12
0.15
0.02
0.01
0.03
0.23
0.23
0.00
0.00
0.03
0.38
0.28
0.06
0.16
Distance traveled, cm
Average speed, cm/s
578.64 96.56 484.63 74.19 499.13 66.96 422.14↓ 41.05
Vertical activity, number of racks
Time of vertical activity, s
Looking into the holes, number of times
Time of looking into the holes, s
Number of jumps
4.78 0.82
20.00 4.14
18.81 4.30
8.63 2.50
3.50 0.94
5.13 4.52
3.99 0.61
4.10 0.56
3.48↓ 0.34
14.25↓ 4.17
15.97 6.12
10.75 4.20
6.34 3.34
18.43 3.31 16.00 5.13
19.36 3.97 13.68 5.63
10.14 3.44 14.29↑ 5.38
5.68↑ 1.97 9.86↑ 3.95
Vertical distance, cm
1.29 1.50
0.57↓ 0.79
1.50 1.20
* Up arrow (↑) shows increase of indicator, down arrow (↓) shows decrease, confidence level p < 0.05 in comparison with intact control.
Table 2. Comparison of intragastric (i/g) and intraperitoneal (i/p) administration at a dose of 50 mg/kg of compound 11
in the open field test after a single injection (n = 8, duration 2 min)*
Level of reliability in comparison
with intact control
Compound
Intact
control
Test indicators
Compound
11 (i/g)
11 (i/p)
11 (i/g)
11 (i/p)
Total locomotor activity,
80.88 8.34
76.13 3.60
75.86 6.47
0.279
0.336
number of locomotor acts
Locomotor activity, s
72.38 7.36
47.63 7.36
480.00 116.90
3.95 0.98
76.66 5.11
43.34 5.11
463.25 42.60
3.81 0.36
80.00 5.42
40.00 5.42
528.90 85.62
4.36 0.70
0.234
0.234
0.574
0.645
0.279
0.382
0.130
0.003
0.234
0.054
0.054
0.397
0.463
0.040
0.014
0.021
0.000
0.867
Distance traveled, cm
Average speed, cm/s
Vertical activity, number of racks
Time of vertical activity, s
Looking into the holes, number of times
Time of looking into the holes, s
Number of jumps
15.88 5.54
16.44 5.63
6.88 3.83
18.00 4.31
20.38 8.07
11.50 6.09
6.50↑ 3.55
0.88 0.83
24.71↑ 8.73
25.79↑ 6.39
11.71↑ 2.50
7.25↑ 1.49
3.57 3.91
2.53 1.27
Vertical distance, cm
3.25 3.45
* Up arrow (↑) shows increase of indicator, down arrow (↓) shows decrease, confidence level p < 0.05 in comparison with intact control.
The study also determined the effect of the test
compound on locomotor activity against the background of
diazepam. Compounds 5, 8, 11 were administered
intraperitoneally at a dose of 50 mg/kg 30 min before the
administration of diazepam. After administration of
diazepam, animals were tested after 30 min. As a result of
the experiment, it was found that compounds 5, 8, 11 did
not significantly aggravate or stop the relaxing effect of
diazepam (Table 3).
To determine the effect of target compound 11 on the
relaxing effect of chloral hydrate, a chloral hydrate sleep
test was performed. It is important to note that there were
no significant deviations in sleep time caused by chloral
hydrate under the influence of the studied compounds.
The obtained 1-(2-acetoxyethyl)uracil derivatives are
similar in pharmacological activity to the previously
described related N(3)-(phenylcarbamoyl)methylquinazolin-
4(3H)-ones20–22 possessing antidepressant and nootropic
properties, rather than to 3-phenacyluridine and its analogs.
It should be noted that an important component of the final
product structure, which determines the psycho-
pharmacological effect, is the presence of an acetylated or
nonacetylated 1-(2-hydroxyethyl)uracil fragment. The
obtained compounds contain a fragment of α-aminoaceto-
phenone, which makes them related to the psycho-
stimulants of the cathinone group; however, a decrease in
the basicity of the nitrogen atom due to its inclusion in the
pyrimidine ring significantly weakens the psychostimu-
lating properties of the prototype substances. We believe
that the target compounds may be of more interest as
probable antiviral agents, similar in structure to the
previously studied substances with the corresponding
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Chemistry of Heterocyclic Compounds 2020, 56(6), 769–775
Table 3. The effect of compounds 5, 8, 11 on the locomotor response of animals
in the open field test after a single intraperitoneal injection at a dose of 50 mg/kg against diazepam at a dose of 10 mg/kg
(n = 8, duration 2 min)
Compound
Intact
Test indicators
control
Diazepam
5
8
11
Total locomotor activity,
number of locomotor acts
68.00#↑ 5.15
54.00*↓ 15.3
63.13 23.62
52.38*↓ 19.11
49.25*↓ 9.03
Locomotor activity, s
82.94 6.64
37.06 6.64
573.46 90.91
4.74 0.76
75.06 29.62
44.94 29.62
690.41 354.55
5.73 2.92
57.06 25.76
62.94 25.76
456.83 281.69
3.76 2.33
70.72 27.90
49.28 27.90
552.29 249.44
4.54 2.07
73.81 26.59
46.19 26.59
585.80 301.93
4.83 2.52
Distance traveled, cm
Average speed, cm/s
Vertical activity, number of racks
Time of vertical activity, s
Looking into the holes, number of times
Time of looking into the holes, s
Number of jumps
17.25#↑ 5.60
17.94#↑ 4.79
10.13#↑ 1.25
4.44#↑ 1.05
2.25 2.87
11.50 12.24
8.75 9.04
2.50#↓*↓ 6.68
2.13#↓*↓ 5.62
2.63*↓ 2.56
1.06*↓ 1.05
9.88*↑ 9.03
5.25*↓ 4.53
4.06*↓ 5.0
3.63*↓ 3.50
1.25*↓ 1.32
3.63 3.42
4.75*↓ 3.10
2.94*↓ 1.53
1.75*↓ 0.96
0.69*↓ 0.43
3.00 2.00
4.50*↓ 4.84
1.59*↓ 2.10
8.25#↑*↑ 3.65
Vertical distance, cm
# Reliability level p <0.05 compared with diazepam, #↓ – decrease of indicator relative to diazepam, #↑ – increase of indicator relative to diazepam.
*
confidence level
p
<0.05 in comparison with intact control, *↓
–
decrease of indicator relative to intact control,
*↑ – increase of indicator relative to intact control.
activity,8,23–27 rather than as the basis for the construction of
new hypnotic agents.
To conclude, the title compounds are not of interest as
hypnotics, but seem to be enough promising as potential
antiviral agents.
Panreac (221074, HPLC-gradient grade) and orthophos-
phoric acid supplied by ''Komponent-Reaktiv'' (extra pure
17-4) were used. Solvents were dried according to standard
methods.28
The starting 2,4-bis[(trimethylsilyl)oxy]pyrimidine (2),29
1-[(2-hydroxyethoxy)methyl]uracil acetate (3)17 and 1-(2-
hydroxyethyl)uracil acetate (4)18 were obtained in
accordance with the methods described earlier.
Experimental
1H and 13C NMR spectra were acquired on a Bruker
AM 360 spectrometer (360 and 90 MHz, respectively) in
CDCl3, with TMS as internal standard. HPLC control was
performed using a chromatographic system consisting of a
Jasco PU-980 pumping unit, Jasco UV-975 UV detector,
and Rheodyne injection systems under the following
conditions: Reprosil C18 AQ (150 × 4.6 mm) column,
3 μm, 0.9 ml/min, λ 220 nm, 30°C temperature, mobile
phase: Н2О–MeCN–H3PO4 (85%) in a 200:200:1 ratio.
HPLC-MS analysis was performed on an Agilent 1200
instrument under the following conditions: Reprosil-Pur
Basic C18 (250 × 4.6 mm) column, 5 μm (Dr. Maisch
GmbH); eluents: 0.01% CF3COOH–H2O (A), 0.01%
CF3COOH–MeCN (B); 1 ml/min flow rate; a VWD single-
wave UV/VID detector, ELSD-detector, and Agilent 6310
Ion Trap LCMS (in positive ion mode) were used for
detection. Preparative HPLC separation of reaction
products was carried out on a semipreparative system with
Gilson pumps (blocks 305 and 306), Gilson 805
manometric module, Jetchrom UVV-105 detector,
ReproSil Pure Basic C 18 column (250 × 20 mm), 10 nm;
10 ml/min flow rate, with UV detection at λ 220 nm.
Elemental analysis was performed on a vario EL cube.
TLC was performed on Polygram Sil G/UV254 and Merck
TLC F254 plates, visualization under UV light. Silica gel
L14002 (Alfa Aesar) with a dispersion of 0.06–0.20 mm
(70–230 mesh) was used for column chromatography.
Synthesis of pyrimidine-2,4(1Н,3Н)-diones 5–7
(General procedure). Method I. A suspension of K2CO3
(0.44 g, 3.18 mmol) in a solution of 1-[2-(acetoxyethoxy)-
methyl]uracil (3) (0.6 g, 2.63 mmol) and the respective
alkylating agent (2.76 mmol) in anhydrous DMF (30 ml)
was stirred under protection from atmospheric moisture until
HPLC analysis of an aliquot of the reaction mixture
showed the absence of the starting compound 3. The
resulting mixture was filtered, the filter cake was washed
with DMF (2×10 ml), and the filtrate was evaporated to dry-
ness under reduced pressure. Traces of DMF were removed
by coevaporation of the residue with PhMe (2×15 ml)
under reduced pressure. The crude product was treated with
Н2О (120 ml) and extracted with EtOAc (3×75 ml).
Organic extracts were combined, washed with Н2О (2×25 ml),
saturated aqueous NaCl (3×25 ml), filtered, and dried over
anhydrous Na2SO4. The desiccant was separated by
filtration, the filtrate was evaporated to dryness under
reduced pressure. The residue was dissolved in a minimum
volume of THF and sorbed on silica gel. The product was
purified by column chromatography by gravity elution with
EtOAc. The product is then further purified by preparative
HPLC.
2-{[2,4-Dioxo-3-(2-oxo-2-phenylethyl)-3,4-dihydropyri-
midin-1(2Н)-yl]methoxy}ethyl acetate (5). Yield 440 mg
(48%), assay 79% (UV). Yield after preparative HPLC
210 mg (23%), colorless syrup, assay 100% (ELSD). Rf 0.52
(EtOAc), 0.40 (EtOAc–cyclohexane, 4:1). 1H NMR spectrum,
The reagents and solvents used were supplied by Alfa
Aesar and Acros Organics. For HPLC, MeCN supplied by
772

Chemistry of Heterocyclic Compounds 2020, 56(6), 769–775
1
2
δ, ppm (J, Hz): 2.07 (3H, s, CH3); 3.77–3.80 (2H, m,
OCH2CH2); 4.21–4.23 (2H, m, OCH2CH2); 5.23 (2H, s,
NCH2O); 5.38 (2H, s, NCH2C(O)); 5.88 (1H, d, J = 8.3,
6-CH pyrimidine); 7.35 (1H, d, J = 7.9, 5-CH pyrimidine);
7.46–7.51 (2H, m, H-3,5); 7.58–7.63 (1H, m, H-4); 7.97–
8.00 (2H, m, H-2,6). 13C NMR spectrum, δ, ppm: 20.7
(СH3C(O)O); 46.9 (CH2C(O)); 62.9 (CH2); 67.6 (CH2);
77.3 (CH2); 102.6 (6-CH pyrimidine); 128.0 (2CH Ar);
128.7 (2CH Ar); 133.7 (CH Ar); 134.8; 141.2 (5-CH
pyrimidine); 151.6; 162.1; 170.6; 191.3 (C(O) Ar). Found,
%: С 59.14; Н 5.40; N 7.89. С17H18N2O6. Calculated, %:
С 58.96; Н 5.24; N 8.09.
2-({3-[2-(4-Methoxyphenyl)-2-oxoethyl]-2,4-dioxo-3,4-di-
hydropyrimidin-1(2Н)-yl}methoxy)ethyl acetate (6).
Yield 420 mg (42%), assay 83% (UV). Yield after
preparative HPLC 270 mg (27%), colorless syrup, assay
100% (ELSD). Rf 0.45 (EtOAc), 0.31 (EtOAc–cyclo-
hexane, 4:1). 1H NMR spectrum, δ, ppm (J, Hz): 2.07 (3H,
s, CH3); 3.77–3.80 (2H, m, OCH2CH2); 3.87 (3H, s, OCH3);
4.20–4.23 (2H, m, OCH2CH2); 5.22 (2H, s, NCH2O); 5.34
(2H, s, NCH2C(O)); 5.87 (1H, d, J = 7.9, 6-CH pyrimidine);
6.93–6.97 (2H, m, H-3,5); 7.34 (1H, d, J = 7.9, 5-CH
pyrimidine); 7.94–7.98 (2H, m, H-2,6). 13C NMR
spectrum, δ, ppm: 20.7 (СH3C(O)O); 46.5 (CH2C(O)); 55.4
(СH3O); 62.9 (CH2); 67.5 (CH2); 77.3 (CH2); 102.6 (6-CH
pyrimidine); 113.9 (2CH Ar); 127.9; 130.2 (2CH Ar);
141.2 (5-CH pyrimidine); 151.6; 162.1; 163.9; 170.6; 189.7
(C(O)Ar). Found, %: С 57.76; Н 5.50; N 7.80. С18H20N2O7.
Calculated, %: С 57.44; Н 5.36; N 7.44.
dd, J = 10.4, J = 10.4, NCH2O); 5.78 (1H, d, J = 7.9,
6-CH pyrimidine); 5.96 (1H, q, J = 6.5, CH3CH); 7.16 (1H,
d, J = 7.9, 5-CH pyrimidine); 7.30–7.35 (2H, m, H-3,5); 7.41–
7.46 (1H, m, H-4); 7.62–7.65 (2H, m, H-2,6). 13C NMR
spectrum, δ, ppm: 13.1 (СH3CH); 20.7 (СH3C(O)O); 53.3
(СH3CH); 62.5 (CH2); 66.8 (CH2); 76.9 (CH2); 102.6
(6-CH pyrimidine); 127.2 (2CH Ar); 128.2 (2CH Ar);
132.1 (CH Ar); 136.3; 136.3 (5-CH pyrimidine); 150.5;
161.7; 170.4; 196.8 (C(O) Ar). Found, %: С 60.21; Н 5.81;
N 8.00. С18H20N2O6. Calculated, %: С 59.99; Н 5.59;
N 7.77.
2-({3-[1-(4-Methoxyphenyl)-1-oxopropan-2-yl]-2,4-di-
oxo-3,4-dihydropyrimidin-1(2Н)-yl}methoxy)ethyl ace-
tate (9). Yield 420 mg (41%), assay 74% (UV). Yield after
preparative HPLC 201 mg (19%), colorless syrup, assay
100% (ELSD). Rf 0.62 (EtOAc), 0.34 (EtOAc–cyclo-
hexane, 4:1). 1H NMR spectrum, δ, ppm (J, Hz): 1.59 (3H,
d, J = 6.8, CH3CH); 2.02 (3H, s, CH3C(O)O); 3.14–3.44
(2H, m, OCH2CH2); 3.80 (3H, s, OCH32); 3.93–4.06 (2H, m,
1
OCH2CH2); 5.05 (2H, dd, J = 10.4, J = 10.4, NCH2O);
5.79 (1H, d, J = 7.9, 6-CH pyrimidine); 5.93 (1H, q, J = 6.6,
CH3CH); 6.80–6.84 (2H, m, H-3,5); 7.18 (1H, d, J = 7.6,
5-CH pyrimidine); 7.61–7.65 (2H, m, H-2,6). 13C NMR
spectrum, δ, ppm: 13.2 (СH3CH); 20.7 (СH3C(O)O); 53.1
(СH3CH); 55.3 (OCH3); 62.6 (CH2); 66.9 (CH2); 76.9
(CH2); 102.6 (6-CH pyrimidine); 113.5 (CH Ar); 128.8;
129.4 (CH Ar); 141.4 (5-CH pyrimidine); 150.5; 161.7;
162.8; 170.4; 195.2 (C(O) Ar). Found, %: С 58.31; Н 5.30;
N 6.97. С19H22N2O7. Calculated, %: С 58.46; Н 5.68; N 7.18.
2-[(3-{[(4-Fluorophenyl)sulfanyl]methyl}-2,4-dioxo-
3,4-dihydropyrimidin-1(2H)-yl)methoxy]ethyl acetate
(10). Yield 700 mg (72%). Yield after preparative HPLC
340 mg (35%), yellowish oil, assay 100% (ELSD). Rf 0.67
(EtOAc), 0.38 (EtOAc–cyclohexane, 4:1). 1H NMR
spectrum, δ, ppm (J, Hz): 2.04 (3H, s, CH3); 3.68–3.71
(2H, m, OCH2CH2); 4.17–4.19 (2H, m, OCH2CH2); 5.15
(2H, s, NCH2O); 5.25 (2H, s, NCH2S); 5.76 (1H, d, J = 7.9,
6-CH pyrimidine); 6.93–6.99 (2H, m, H-3,5); 7.24 (1H, d,
J = 7.9, 5-CH pyrimidine); 7.46–7.52 (2H, m, H-2,6).
13C NMR spectrum, δ, ppm: 20.7 (СH3C(O)O); 46.1
(CH2S); 62.7 (CH2); 67.6 (CH2); 77.5 (CH2); 102.4 (6-CH
pyrimidine); 115.7 (CH Ar); 116.0 (CH Ar); 128.8; 135.1
(2CH Ar); 141.0 (5-CH pyrimidine); 150.9; 161.3; 164.0;
170.5. Found, %: С 51.98; Н 4.31; N 7.61; S 9.00.
С16H17FN2O5S. Calculated, %: С 52.17; Н 4.65; N 7.60;
S 8.70.
2-({3-[2-(4-Fluorophenyl)-2-oxoethyl]-2,4-dioxo-3,4-di-
hydropyrimidin-1(2Н)-yl}methoxy)ethyl acetate (7).
Yield 700 mg (73%), assay 81% (UV). Yield after
preparative HPLC 291 mg (30%), white crystals, assay
100% (ELSD). Mp 105.6–106.2°С. Rf 0.51 (EtOAc), 0.38
1
(EtOAc–cyclohexane, 4:1). H NMR spectrum, δ, ppm
(J, Hz): 2.07 (3H, s, CH3); 3.77–3.79 (2H, m, OCH2CH2);
4.20–4.23 (2H, m, OCH2CH2); 5.22 (2H, s, NCH2O); 5.34
(2H, s, NCH2C(O)); 5.87 (1H, d, J = 7.9, 6-CH pyrimidine);
7.13–7.19 (2H, m, H-3,5); 7.35 (1H, d, J = 7.9, 5-CH
pyrimidine); 7.99–8.04 (2H, m, H-2,6). 13C NMR
spectrum, δ, ppm: 20.7 (СH3C(O)O); 46.7 (CH2C(O)); 62.8
(CH2); 67.6 (CH2); 77.3 (CH2); 102.5 (6-CH pyrimidine);
115.8 (CH Ar); 116.0 (CH Ar); 131.2 (2CH Ar); 131.3;
141.3 (5-CH pyrimidine); 151.6; 162.0; 164.6; 167.4;
170.6; 189.8 (C(O) Ar). Found, %: С 55.89; Н 4.82;
N 7.41. С17H17FN2O6. Calculated, %: С 56.04; Н 4.70;
N 7.69.
2-[2,4-Dioxo-3-(2-oxo-2-phenylethyl)-3,4-dihydropyri-
midin-1(2Н)-yl]ethyl acetate (11). Obtained according to
method II from 1-(2-acetoxyethyl)uracil (4) (0.62 g,
3.13 mmol), K2CO3 (0.52 g, 3.29 mmol), 2-bromo-
1-phenylethan-1-one (0.65 g, 3.75 mmol), and anhydrous
MeCN (75 ml). Yield 510 mg (52%). Yield after
preparative HPLC 250 mg (25%), colorless syrup, assay
Synthesis of pyrimidine-2,4(1Н,3Н)-diones 8–10
(General procedure). Method II. Similar to method I,
except for using anhydrous MeCN (40 ml) as the solvent
and carrying out the synthesis at reflux.
2-{[2,4-Dioxo-3-(1-oxo-1-phenylpropan-2-yl)-3,4-di-
hydropyrimidin-1(2Н)-yl]methoxy}ethyl acetate (8).
Yield 400 mg (42%), assay 87% (UV). Yield after
preparative HPLC 390 mg (41%), colorless syrup, assay
100% (ELSD). Rf 0.69 (EtOAc), 0.44 (EtOAc–cyclo-
hexane, 4:1). 1H NMR spectrum, δ, ppm (J, Hz): 1.61 (3H,
d, J = 6.8, CH3CH); 2.02 (3H, s, CH3C(O)O); 3.07–3.39
(2H, m, OCH2CH2); 3.92–4.05 (2H, m, OCH2CH2); 4.97 (2H,
1
100% (ELSD). Rf 0.53 (EtOAc). H NMR spectrum, δ, ppm
(J, Hz): 2.07 (3Н, s, СН3); 3.90 (2Н, t, J = 1.9, OСН2CH2);
4.30 (2Н, t, J = 1.9, OСН2CH2); 5.38 (2H, s, NCH2C(O));
5.79–5.81 (1H, d, J = 2.9, 6-СН pyrimidine); 7.19–7.21
(1H, d, J = 2.8, 5-СН pyrimidine); 7.46–7.51 (2Н, m,
H-2,6); 7.58–7.62 (1Н, m, H-4); 7.97–8.00 (2Н, m,
773

Chemistry of Heterocyclic Compounds 2020, 56(6), 769–775
H-3,5). 13C NMR spectrum, δ, ppm: 20.6 (СН3С(О)); 47.0
3. ''Chloral hydrate sleep'' was caused by intraperitoneal
administration of the hypnotic chloral hydrate in a dose of
325 mg/kg. The criterion for evaluating the effect was the
time of loss and restoration of the reflex of turning of the
mice from a lateral position.31 The time of falling asleep,
awakening, and duration of sleep were estimated. The
duration of sleep was calculated by the difference between
the indicator of time falling asleep (the moment of loss of
the flipping reflex) and the time of awakening (reflex
recovery).
Chloral hydrate and diazepam were administered after
1 h for intragastric administration and after 30 min for
intraperitoneal administration of the test compounds.
Statistical data processing was carried out using the
program Statistica 6.0. Data are presented as the arithmetic
mean and standard error of the mean. Comparisons
between groups were performed using the nonparametric
Mann–Whitney U test. For a significant level of
significance, p ≤0.05. Differences at the trend level were
considered at 0.05 <p <0.1.
(СН2С(О)); 61.7 (СН2); 77.0 (СН2); 101.4 (6-СН
pyrimidine); 128.0 (2СН Ar); 128.7 (2СН Ar); 133.6 (СН
Ar); 134.8; 142.8 (5-СН pyrimidine); 151.2; 162.3; 170.3;
191.8 (С(О) Ar). Found, %: С 61.00; Н 4.89; N 9.01.
С16H16N2O5. Calculated, %: С 60.76; Н 5.10; N 8.86.
Biological activity of the obtained compounds was
studied on female outbred (nonlinear) laboratory mice
(CD-1) weighing 20–25 g. Animals were obtained from the
vivarium of the Federal Research Center of the Institute of
Cytology and Genetics, Siberian Branch of the Russian
Academy of Sciences, where they were kept under standard
vivarium conditions with free access to water and granular
feed. After quarantine, animals were randomized by weight
and divided into groups of 8–10 mice. Work with animals
was carried out in strict accordance with the Order of the
Ministry of Health of the Russian Federation No. 199н
dated April 1, 2016 ''Rules of Good Laboratory Practice''
and the provisions of Directive 2010/63/EU of the
European Parliament (Directive 2010/63/EU on the
protection of animals used for scientific purposes) and the
Council of the European Union of 22 September 2010 on
the protection of animals used for scientific purposes.
Test compounds were administered in two ways:
This work was supported by the Russian Science
Foundation (grant 19-13-00123) using the equipment
of the Center for Collective Use ''Physico-Chemical
Research Methods'' of Volgograd State Technical
University.
1. Intragastrically (i/g) with a probe, once, in the form of
a thin suspension in Tween-20 with a volume of 0.2 ml per
10 g of body weight at a dose of 10 or 50 mg/kg. The
control group of animals were injected with an equal
volume of aqueous Tween solution intragastrically.
References
2. Intraperitoneally (i/p) with an insulin syringe, once,
sterile solution of 0.9% NaCl was used as the solvent with
a volume of 0.1 ml per 10 g of body weight at a dose of 10
or 50 mg/kg. An equal volume of solvent was also
administered intraperitoneally to the control group of
animals.
1. Tanious, M. K.; Beutler, S. S.; Kaye, A. D.; Urman, R. D.
Anesthesiol. Clin. 2017, 35, e95.
2. Yamamoto, I.; Kuze, J.; Kimura, T.; Watanabe, K.; Kondo, S.;
Ho, I. K. Biol. Pharm. Bull. 1994, 17, 514.
3. Kimura, T.; Kuze, J.; Watanabe, K.; Kondo, S.; Ho, I. K.;
Yamamoto, I. Eur. J. Pharmacol. 1996, 311, 265.
4. Kimura, T.; Miki, M.; Ikeda, M.; Yonemoto, S.; Watanabe, K.;
Kondo, S.; Ho, I. K.; Yamamoto, I. Biol. Pharm. Bull. 2001,
24, 729.
5. Kimura, T.; Ho, I. K.; Yamamoto, I. Sleep 2001, 24, 251.
6. Kimura, T.; Miki, M.; Watanabe, K.; Kondo, S.; Ho, I. K.;
Yamamoto, I. Xenobiotica 2000, 30, 643.
7. Kimura, T.; Kuze, J.; Teraoka, S.; Watanabe, K.; Tateoka, Y.;
Kondo, S.; Ho, I. K.; Yamamoto, I. Biol. Pharm. Bull. 1996,
19, 142.
The choice of doses was justified by the literature data
for 3-phenacyluridine and its analogs.2,15,16
The following tests were used to determine the effect of
the test compounds on the central nervous system:
1. Determination of the locomotor response of animals
in the open field test30 using an automated TruScan
photosensor installation (Coulbourn, USA), which is a
square arena measuring 26 × 26 × 33 cm (length × width ×
height) and contains 16 evenly spaced holes (burrows) with
a diameter of 2.2 cm. The test animal was placed in the
center of the installation with its tail to the experimenter
one hour after a single intragastric administration of the
studied agents. Within 2 min, the following indicators were
recorded: total locomotor activity (number of locomotor
acts), time of locomotor activity (s), distance traveled (cm),
average speed (cm/s), number of jumps, vertical activity
(number of racks), time of vertical activity (s), number and
time of looking (s) into holes, vertical distance (cm).
2. Locomotor activity against the background of
diazepam (diazepam was administered intraperitoneally at
a dose of 10 mg/kg.31 Locomotor response of animals was
evaluated 30 min after the administration of diazepam by
the open field test30 using an automated TruScan
photosensor system (Coulbourn, USA).
8. Sato, Y.; Utsumi, K.; Maruyama, T.; Kimura, T.; Yamamoto, I.;
Richman, D. D. Chem. Pharm. Bull. 1994, 42, 595.
9. Maruyama, T.; Kozai, S.; Shimizu, T.; Kimura, T.; Watanabe, K.;
Yamamoto, I. Nucleic Acids Res. Suppl. 2003, 25.
10. Shimizu, T.; Kimura, T.; Funahashi, T.; Watanabe, K.; Ho, I. K.;
Yamamoto, I. Chem. Pharm. Bull. 2005, 53, 313.
11. Yamamoto, I.; Kimura, T.; Tateoka, Y.; Watanabe, K.; Ho, I. K.
Chem. Pharm. Bull. 1985, 33, 4088.
12. Yamamoto, I.; Kimura, T.; Tateoka, Y.; Watanabe, K.; Ho I. K.
J. Med. Chem. 1987, 30, 2227.
13. Tateoka, Y.; Hiramura, S.; Usami, N.; Kimura, T.; Watanabe, K.;
Yamamoto, I. Yakugaku Zasshi 1992, 112, 470.
14. Koshigami, M.; Watanabe, K.; Kamura, T.; Yamamoto, I.
Chem. Pharm. Bull. 1991, 39, 2597.
15. Kimura, T.; Watanabe, K.; Tateoka, Y.; Kondo, S.; Ho, I. K.;
Yamamoto, I. Chem. Pharm. Bull. 1993, 41, 1180.
16. Kimura, T.; Yao, S.; Watanabe, K.; Kondo, S.; Ho, I. K.;
Yamamoto, I. Chem. Pharm. Bull. 2001, 49, 111.
774

Chemistry of Heterocyclic Compounds 2020, 56(6), 769–775
17. Matsumoto, H.; Kaneko, C.; Yamada, K.; Takeuchi, T.;
24. Babkov, D. A.; Paramonova, M. P.; Ozerov, A. A.;
Khandazhinskaya, A. L.; Snoeck, R.; Andrei, G.; Novikov, M. S.
Acta Naturae 2015, 7, 142.
Mori, T.; Mizuno, Y. Chem. Pharm. Bull. 1988, 36,
1153.
18. Novakov, I. А.; Babushkin, А. S.; Brunilina, L. L.;
Kirillov, I. А.; Navrotskii, М. B.; Robinovich, М. D.;
Yablokov, А. S. RF Patent 2697804 C1.
19. Karkishchenko, N. N.; Tarakanov А. V. Experimental and
clinical pharmacology of neuro-psychotropic drugs [in
Russian]; Rostov-on-Don: RODNMI, 1985.
20. Tyurenkov, I. N.; Ozerov, A. A.; Solodunova, E. A.;
Archakova, Yu. V.; Shmatova, E. N. Pharm. Chem. J. 2013,
47, 239. [Khim-Farm. Zh. 2013, 47(5), 7.]
21. Archakova, Yu. V.; Glukhova, E. G.; Shmatova, Е. N.;
Solodunova, Е. А.; Tyurenkov, I. N.; Novikov, M. S.;
Ozerov, А. А. Uspekhi sovremennogo estestvoznaniya 2016,
3, 9.
22. Tyurenkov, I. N.; Ozerov, A. A.; Shmatova, E. N.;
Archakova, Yu. V. Pharm. Chem. J. 2015, 49, 88. [Khim.
Farm. Zh. 2015, 49(2), 18.]
25. Novikov, M. S.; Babkov, D. A.; Paramonova, M. P.;
Chizhov, A. O.; Khandazhinskaya, A. L.; Seley-Radtke, K. L.
Tetrahedron Lett. 2013, 54, 576.
26. Novikov, M. S.; Babkov, D. A.; Paramonova, M. P.;
Khandazhinskaya, A. L.; Ozerov, A. A.; Chizhov, A. O.;
Andrei, G.; Snoeck, R.; Balzarini, J.; Seley-Radtke, K. L.
Bioorg. Med. Chem. 2013, 21, 4151.
27. Paramonova, M. P.; Ozerov, A. A.; Chizov, A. O.; Snoeck, R.;
Andrei, G.; Khandazhinskaya, A. L.; Novikov, M. S.
Mendeleev Commun. 2019, 29, 638.
28. Tietze, L. F.; Eicher, T. Preparative Organic Chemistry.
Reactions and Syntheses in the Organic Chemistry
Laboratory [Russian translation]; Moscow: Mir, 1999.
29. Kaulinya, L. T.; Liepin'sh, E. E.; Lidak, M. Yu.; Zhuk, R. A.
Chem. Heterocycl. Compd. 1982, 18, 85. [Khim. Geterotsikl.
Soedin. 1982, 101.]
23. Magri, A.; Ozerov, A. A.; Tunitskaya, V. L.; Valuev-Elliston, V. T.;
Wahid, A.; Pirisi, M.; Simmonds, P.; Ivanov, A. V.;
Novikov, M. S.; Patel, A. H. Sci. Rep. 2016, 6, 29487.
30. Walsh, R. N.; Cummins, R. A. Psychol. Bull. 1976, 83, 482.
31. Tolstikova, T. G.; Voevoda, Т. V.; Dolgikh, M. P.;
Sorokina, I. V. Eksperim. Klin. Farmakol. 2002, 65(2), 9.
775