Synthesis of 6-arylvinyl analogues of the HIV drugs SJ-3366 and Emivirine

Article abstract of DOI:10.1016/j.bmc.2003.11.032

This paper reports the synthesis and the antiviral activities of a series of 6-arylvinyl substituted analogues of SJ-3366, a highly potent agent against HIV. The objective was to investigate whether substitution of the 6-arylketone with a 6-arylvinyl grou

Full text of DOI:10.1016/j.bmc.2003.11.032

Bioorganic & Medicinal Chemistry 12 (2004) 1141–1149
Synthesis of 6-arylvinyl analogues of the HIV drugs
SJ-3366 and Emivirine
Michael Wamberg,a Erik B. Pedersen,a,* Nasser R. El-Brollosya and Claus Nielsenb
aNucleic Acid Centery, Department of Chemistry, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
bRetrovirus Laboratory, Department of Virology, State Serum Institute, Artillerivej 5, DK-2300 Copenhagen S, Denmark
Received 7 July 2003; accepted 28 November 2003
Abstract—This paper reports the synthesis and the antiviral activities of a series of 6-arylvinyl substituted analogues of SJ-3366, a
highly potent agent against HIV. The objective was to investigate whether substitution of the 6-arylketone with a 6-arylvinyl group
could lead to an improved antiviral activity against HIV-1. The most active compounds 1-ethoxymethyl, 1-(2-propynyloxymethyl),
and 1-(2-methyl-3-phenylallyloxymethyl) substituted 6-[1-(3,5-dimethylphenyl)vinyl]-5-ethyl-1H-pyrimidine-2,4-dione (5b, 16, and
18) showed activities against HIV-1 wild type in the range of Efavirenz, and moderate activities against Y181C and
Y181C+K103N mutant strains were also observed.
# 2003 Elsevier Ltd. All rights reserved.
1. Introduction
In the treatment of patients suffering from HIV/AIDS
four classes of compounds are used, fusion inhibitors,
protease inhibitors (PIs), nucleoside reverse tran-
scriptase inhibitors (NRTIs), and non-nucleoside
Figure 1.
reverse transcriptase inhibitors (NNRTIs). The latter
consist of many classes of compounds (reviewed in ref
1), and among them the most potent anti-HIV agents
are found. The NNRTIs are highly specific as their
binding site is a hydrophobic pocket located approxi-
mately 10 A from the polymerase active site.2 They bind
allosterically forcing the RT-subunit into an inactive
conformation.3 However, the specificity results in
NNRTI being vulnerable to mutations among the
amino acids around the binding site,4 which leads to
drug resistance. A serious concern is the commonly
found Y181C mutation which causes loss of antiviral
activity among all NNRTIs including the FDA (US
Food and Drug Administration) approved drugs,
Nevirapine,5 Delavirdine,6 and Efavirenz.7
scriptase (RT). But it was not acting as a NRTI as no
activity against HIV-2 was measured. A new inhibitory
mechanism was found and therefore HEPT was con-
sidered a lead compound for NNRTI synthesis, even
though it was not very active itself. Among the many
HEPT analogues synthesized in the last decade are
Emivirine10À12 (formerly known as MKC-442), GCA-
186,13 and SJ-336614 which all showed potent activity
against HIV-1 (Fig. 1).
Emivirine was chosen as a drug candidate for clinical
trials15 by Triangle Pharmaceuticals, but phase III
studies was abandoned in January 2002, when com-
parative studies showed Emivirine to be less potent than
other anti-HIV compounds.16 Meanwhile it was repor-
ted that Emivirine triggers the liver enzyme Cytochrome
P450, leading to drug interactions between Emivirine
and protease inhibitors.17
One of the first NNRTIs was 1-[(2-hydroxy-
ethoxy)methyl]-6-(phenylthio)thymine (HEPT)8,9 which
was synthesized in 1989. It was originally designed as a
chain terminator in the viral enzyme Reverse Tran-
GCA-186 differs structurally from Emivirine only in
the introduction of two methyl substituents in 3- and
5-position at the C-6 benzyl group. This modification
has improved the antiviral acitivity against the wild type
* Corresponding author. Tel.: +45-6550-2555; fax: +45-6615-8780;
e-mail: EBP@chem.sdi.dk
A research center founded by The Danish National Research Foun-
dation for studies on nucleic acid chemical biology.
y
0968-0896/$ - see front matter # 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2003.11.032

1142
M. Wamberg et al. / Bioorg. Med. Chem. 12 (2004) 1141–1149
HIV-1, but more interesting also against the mutated
HIV strains. The loss in activity towards the Y181C
mutation is significantly lower for GCA-186 than for
Emivirine.13
SJ-3366 is a highly potent inhibitor of HIV-1, that con-
trary to other NNRTIs; also shows activity against
HIV-2. Besides the inhibitory effect on HIV-1 RT, SJ-
3366 also inhibits the attachment of HIV-1 and HIV-2
to the target cells. The inhibitory concentration against
HIV-1 has been reported to be approximately 1 nM in
CEM-SS T cells.14
This paper reports a series of 6-arylvinyl substituted
analogues of SJ-3366. The objective was to investigate
whether substitution of the 6-arylketone with an iso-
steric 6-arylvinyl group could lead to an improved anti-
viral activity against HIV-1. In addition, the synthesis of
new HEPT analogues would also provide information
to the ongoing investigation of the NNRTI binding site.
Scheme 1. (a) Ref 18; (b) ArCH2CN, NaH, DMF; (c) NaH, O2,
DMF, 66–93% (one-pot synthesis); (d) CH3MgBr, THF; (e) HCl
(aq), 69–86% (two steps); (f) BSA, CH3CH2OCH2Cl, CHCl3, 24–48%;
(g) BSA, TMS-triflate, RCH2OCH2OCH2R, CH3CN, 10–99%.
2. Chemistry
It was believed that the SJ-3366 analogues could be
synthesized using literature procedures18,19 for the first
two steps to get compound 3 followed by a Wittig reac-
tion for the methylenation of the ketone. The ketones
3a–c were prepared in 66–93% yield by a nucleofilic
aromatic substitution with arylacetonitriles in a one-pot
synthesis19 where the intermediate nitrile was immedi-
ately oxidized to the ketone by passing pure oxygen
through the reaction mixture. The Wittig reaction for
obtaining the nucleobase 4 did not work when we did
the reaction with methyltriphenylphosphonium bromide
presumably because of steric hindrance of the ketone.
Dolle et al.20 tried to prepare a vinylic HEPT analogue
from (3,5-dimethylphenyl) 5-ethyl-2-methoxy-6-methyl-
3-pivaloylaminopyridin-4-yl ketone in a two step reac-
tion using methyllithium to form a tertiary alcohol but
failed as this alcohol could not be dehydrated under
acidic conditions using p-toluenesulfonic acid, acetic
anhydride nor hydrochloric acid.
under the Vorbruggen conditions23 using BSA, TMS-
triflate as a catalyst, and various substituted bis(ally-
loxy)methanes or bis(propynyloxy)methanes leading to
target molecules 6–19. The latter reagents have been
developed recently in our group to produce active Emi-
virine analogues against HIV in the near picomolar
range.24,25 The yield for the alkylations reactions varied
greatly from 10–99%. Especially the propynyloxymethyl
substituents coupled badly, even though the reaction
time was extended to 3 days. N-1 alkylations were ver-
ified by the NOE enhacement on NCH2O-protons when
vinylic protons were irradiated and vice versa.
1H NMR spectra of the compounds 5–19 revealed
diastereotopic protons in the methylene groups of the
5-ethyl and N-1 alkoxymethyl substituents. This is
ascribed to hindered rotation of the exocyclic bond at
the 6-position of the uracil ring which results in two
enantiomeric rotamers with the phenylvinyl group per-
pendicular to the uracil ring.
Nevertheless, the compounds 3a–c could be converted
to the corresponding 6-arylvinyl substituted compounds
4a–c in a two step reaction in 69–86% yield. First step
was introduction of a methyl group and formation of a
tertiary alcohol by a Grignard reaction with methylmag-
nesium bromide in dry THF as described by Boyd et al.21
for a similar diaryl ketone. The tertiary alcohol was then
dehydrated in refluxing 4M hydrochloric acid. The inter-
mediate alcohol was isolated only for the phenyl com-
pound 4a in order to verify the intermediate product
(Scheme 1).
3. Biological results
Target compounds 5–19 were tested for biological
activity against wild type HIV-1 strain IIIB in MT-4
cells. Results were compared with the anti-viral activity
of Emivirine, a well examined HEPT analogue, and
Efavirenz, the most active anti-HIV drug used in therapy.
Compounds showing an antiviral activity against HIV-1 in
the range of Emivirine (0.02 mM) were also tested against
the HIV-1 strains with Y181C and Y181C+K103N
mutations. All results are listed in Table 1.
A variety of N-1 alkylations on 4 were carried out to get
a series of SJ-3366 and Emivirine analogues to reveal
their biological potential. 4a–c were N-1 alkylated
according to the procedure described by Danel et al.22
using N,O-bis(trimethylsilyl)acetamide (BSA) and
chloromethyl ethyl ether to give 5a–c in 24–48% yield.
Futhermore N-1 alkylations on 4a–b were carried out
4. Discussion
The biological results reveal that a 6-(1-naphthyl)vinyl
group is too big a substituent for this type of analogues,

M. Wamberg et al. / Bioorg. Med. Chem. 12 (2004) 1141–1149
1143
Table 1. Inhibitory and Cytotoxic Concentrations of the SJ-3366 and Emivirine analogues (compounds 5–19). Data for Emivirine and Efavirenz
are given for comparison
Wild type
CC50 (mM)b
Y181C
IC50 (mM)a
Y181C+K103N
IC50 (mM)a
Compd
R1
R2
IC50 (mM)a
SIc
>36
>2857
17
>115
>29
21
91
>67
7
1200
358
187
133
5a
5b
5c
6
7
8
CH3
CH3
CH3
H
CH3
2.8
0.035
4.0
0.87
3.4
3.1
0.32
1.5
>100
>100
66
>100
>100
66
NTd
17
NTd
29
NTd
NTd
NTd
NTd
NTd
NTd
NTd
>100
NTd
NTd
>100
17
NTd
NTd
NTd
NTd
NTd
NTd
NTd
>100
NTd
NTd
>100
23
CH2¼CH
H
H
H
H
H
CH2¼ C(CH)3
(CH3)2C¼ CH
Ph-CH¼ CH
HCꢀC
9
29
10
11
12
13
14
15
16
17
18
19
>100
28
36
Ph-CꢀC
H
3.8
CH2¼ CH
CH2¼ C(CH)3
(CH3)2C¼ CH
Ph-CH¼ CH
HCꢀC
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
0.03
0.10
0.15
0.03
0.03
0.29
0.03
0.30
34
28
4
>100
31
31
>3333
107
1033
113
Ph-CꢀC
NTd
7
NTd
NTd
>100
NTd
Ph-CH¼ C(CH3)
34
Emivirine
Efavirenz
0.02
0.01
>100
>100
>5000
>10,000
44
0.3
>100
2.7
a Inhibitory concentration of compound required to achieve 50% inhibition of HIV-1 multiplication in MT-4-infected cells.
b Cytotoxic concentration of compound required to reduce the viability of normal uninfected MT-4 cells by 50%. The symbol (>) indicates that the
CC50 was not reached at the highest concentration tested.
c Selectivity index: ratio CC50/IC50
d NT: Not tested.
.
as 5c was the least active among the synthesized com-
pounds. A similar conclusion was reached in a recently
published study24 and therefore no further analogues
with 6-(1-naphthyl)vinyl substituents were synthesized.
The remaining compounds in Table 1 can be divided
into two series with reference to their (phenyl)vinyl (6–
11) or (3,5-dimethylphenyl)vinyl (12–19) substituents in
the 6-position.
group result in a drop in activity which could be due to
steric interactions with adjacent amino acids. However,
introduction of a phenylsubstituent at the allyl group
does not result in lower activity. Most likely, this region
of the NNRTI binding site is flexible to larger aromatic
rings with the ability to make p-interactions.
Emivirine analogues having a (2-propynyloxy)methyl
substituent or phenylsubstituted allyloxymethyl at the
N-1 position have shown high activities against HIV-
1.24,25 In continuation of this work a (3-phenyl-2-pro-
pynyloxy)methyl alkylating agent was prepared accord-
ing to the method of Nazaretyan et al.27 as described by
El-Brollosy et al.24 However, compounds 11 and 17
having this (3-phenyl-2-propynyloxy)methyl substituent
in the N-1 position were the least active for R2=H and
CH3, respectively. In comparison, compounds 9 and 15
which instead of the triple bond have a double bond in
the N-1 substituent were among the most active in the
present series of analogues, but also the most toxic ones.
The reason for the lower activity of 11 and 17 may be due
to the low flexibility of the 3-phenyl-2-propynyl system
to allocate the phenyl ring for stacking in the RT.
It is well known, that introduction of 3,5-dimethyl sub-
stituents on the aromatic ring in Emivirine leads to an
up to 100-fold rise in biologic activity.13,26 This is also
the case in the present series of compounds, where the
increase in activity rises up to 80-fold. In analogy with
previous results,13,26 the cytotoxicity for the series with
3,5-dimethyl substituents at the phenyl ring were higher
than for the series without.
As seen from examination of the results listed in Table
1, the substitution pattern of the allyl group at the N-1
substituent should rather be unsubstituted (6,12) or
phenylsubstituted (9,15) than methyl (7,13) or dime-
thylsubstituted (8,14) in order to achieve the more active
compounds. The N-1 substituent of these analogues is
believed to interact with the amino acids in the reverse
transcriptase enzyme, but the exact binding still needs to
be elucidated. It is thought that the allyl group interacts
through p-stacking with RT-amino acid Phe227 or
Pro236. Increasing the bulkyness around this allyl
The five most potent compounds towards the wild type
HIV-1 were also tested against HIV-1 strains with
Y181C and Y181C+K103N mutations. Both strains
are associated with high-level resistance to NNRTIs
Emivirine, Nevirapine, Delavirdine and for the latter

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M. Wamberg et al. / Bioorg. Med. Chem. 12 (2004) 1141–1149
also Efavirenz. 12 and 15 showed no activity at the
highest concentration tested, while 5b, 16 and 18
showed a marginally higher activity against the Y181C
single mutated strain than Emivirine. 5b and 16 were
also active against the Y181C+K103N double mutated
strain.
5.3. 6-[1-(3,5-Dimethylphenyl)vinyl]-5-Ethyl-1H-pyrimid-
ine-2,4-dione (4b)
Yield: 3.85 g (86%); as beige, needle formed crystals;
mp 246–247 ꢁC; Rf 0.51 (10% MeOH/CH2Cl2). 1H
NMR (DMSO-d6): d 0.84 (t, 3H, J=7.1 Hz, CH2CH3),
2.05 (q, 2H, J=7.1 Hz, CH2CH3), 2.29 (s, 6H, 2ꢂCH3),
5.40 (s, 1H, C¼CH2a), 6.01 (s, 1H, C¼CH2b), 7.00 (s,
1H, Harom), 7.05 (s, 2H, Harom), 10.76 (s, 1H, NH),
11.11 (s, 1H, NH). 13C NMR (DMSO-d6): d 13.51
(CH3), 18.46 (CH2), 20.83 (2ꢂCH3), 111.17 (C-5),
117.43 (¼CH2), 123.47, 129.99, 136.17, 137.67 (Carom),
140.23 (C=CH2), 148.89 (C-6), 150.81 (C-2), 164.44 (C-
4). HRMS (MALDI) m/z calcd for C16H18N2O3Na+
(MNa+) 293.1261, found 293.1269. Anal. calcd for
C16H18N2O3: C, 71.09; H, 6.71; N, 10.36. Found: C,
70.90; H, 6.72; N, 10.31.
5. Experimental
NMR spectra were recorded on a Varian Gemini
2000 NMR spectrometer at 300 MHz for 1H and
75 MHz for 13C with TMS as internal standard.
MALDI spectra were recorded on a Fourier Transform
Ion Cyclotron Resonance Mass Spectrometer. Melting
points were determined on a Buchi melting point appa-
ratus. Elementary analyses were performed at H.C.
Ørsted Institute, University of Copenhagen. Silica gel
(0.040–0.063 mm) used for column chromatography
and analytical silica gel TLC plates 60 F254 were pur-
5.4. 5-Ethyl-6-[1-(1-naphthyl)vinyl]-1H-pyrimidine-2,4-
dione (4c)
chased from Merck. UV-light or
a solution of
.
(NH4)6Mo7O24 4H2O (50 g) and Ce2(SO4)3 (1 g) in 5%
sulfuric acid were used for visualization. Solvents used
for column chromatography were distilled prior to use.
Reagents were used as purchased.
Yield: 0.78 g (80%) as brown, needle formed crystals;
mp: decomposes at 244 ꢁC; Rf 0.25 (25% EtOAc/Pet-
roleum ether). 1H NMR (DMSO-d6): d 0.42 (t, 3H,
J=7.2 Hz, CH2CH3), 1.91 (q, 2H, J=7.2 Hz,
CH2CH3), 5.89 (s, 1H, C¼CH2a), 5.97 (s, 1H,
C¼CH2b), 7.49–8.06 (m, 7H, Hnaphthyl) 11.01 (s, 1H,
NH), 11.17 (s, 1H, NH). 13C NMR (DMSO-d6): d
12.57 (CH3), 18.03 (CH2), 111.15 (C-5), 124.50, 124.83,
125.44, 125.99, 126.52, 126.78, 128.59, 128.73, 130.13,
133.39, 136.26 (=CH2, 10ꢂCnaphthyl), 140.05
(C=CH2), 149.04 (C-6), 150.90 (C-2), 164.42 (C-4).
HRMS (MALDI) m/z calcd for C18H17N2O+3 (MH+)
293.1284, found 293.1281.
5.1. General procedure for synthesis of 6-[1-(Aryl)vinyl]-
5-ethylpyrimidine-2,4-diones (4a–c)
6-(Arylcarbonyl)-5-ethyl-2,4-dimethoxypyrimidine (3a–c)
(3–17 mmol) was dissolved in dry THF (50–100 mL)
under nitrogen atmosphere. The solution was cooled to
0 ꢁC, and methylmagnesium bromide (2 equiv, 1.4 M in
THF/Toluene) was added. The temperature was
increased to rt and the solution was stirred at rt for 1–6
days until the colour of the solution turned yellow-red-
dish. Then the reaction was quenched with satd NH4Cl
(50 mL) and extracted with ethylacetate (3ꢂ100 mL).
The combined organic phases were washed with water
(2ꢂ100 mL) and satd NaCl (100 mL) and dried
(MgSO4), the solvent was evaporated off under reduced
pressure yielding a yellow oil.
5.5. General procedure for N-1alkylation of 4a–c
5.5.1. Method A. N,O-bis(trimethylsilyl)acetamide
(BSA) (3 equiv) was dissolved in dry CHCl3 (100 mL)
and the pyrimidine 4 was added. After 20 min, chlor-
omethyl ethyl ether (2 equiv) was added and the solu-
tion was stirred at rt overnight. The reaction was
quenched with satd NaHCO3 (50 mL). The mixture
was evaporated to dryness by co-evaporation with
ethanol (2ꢂ50 mL) under reduced pressure. The solid,
white compound was suspended in diethyl ether (200
mL) and stirred for 2 h, after which the ether was
decanted. This procedure was repeated with more die-
thyl ether (2ꢂ200 mL) The combined ether phases
were washed with satd. NaHCO3 (2ꢂ50 mL) that was
back-extracted with diethyl ether (2ꢂ100 mL). The
combined ether phases were dried (MgSO4) and eva-
porated under reduced pressure. The products were
purified by silica column chromatography using ethyl
acetate (5a) or 25% EtOAc/Petroleum ether (5b and
5c) as eluents.
The oil was refluxed in 4M HCl (80 mL) overnight.
Upon cooling to rt crystals precipitated. These were fil-
tered off and dried in vacuo.
5.2. 5-Ethyl-6-[1-(phenyl)vinyl]-1H-pyrimidine-2,4-dione
(4a)
Yield: 1.07 g (69%) as beige, needle formed crystals; mp
196 ꢁC; Rf 0.45 (10% MeOH/CH2Cl2). 1H NMR
(DMSO-d6): d 0.84 (t, 3H, J=7.2 Hz, CH2CH3), 2.07
(q, 2H, J=7.2 Hz, CH2CH3), 5.46 (s, 1H, C¼CH2a),
6.09 (s, 1H, C¼CH2b), 7.36–7.47 (m, 5H, Harom), 10.81
(s, 1H, NH) 11.12 (s, 1H, NH). 13C NMR (DMSO-d6):
d 13.53 (CH3), 18.43 (CH2), 111.31 (C-5), 117.77
(¼CH2), 125.78, 128.50, 128.68, 136.21 (Carom), 140.05
(C¼CH2), 148.68 (C-6), 150.82 (C-2), 164.41 (C-4).
HRMS (MALDI) m/z calcd for C14H14N2O2Na+
(MNa+) 265.0948, found 265.0946. Anal. calcd for
C14H14N2O2: C, 69.41; H, 5.82; N, 11.56. Found: C,
69.32; H, 5.94; N, 11.02.
5.6. 1-Ethoxymethyl-5-ethyl-6-[1-(phenyl)vinyl]-1H-pyr-
imidine-2,4-dione (5a)
Yield: 69 mg (48%) as beige crystals; mp 80–83 ꢁC; Rf
1
0.59 (EtOAc). H NMR (CDCl3): d 0.99 (t, 3H, J=7.1
Hz, CH2CH3), 1.03 (t, 3H, J=7.0 Hz, OCH2CH3), 2.15

M. Wamberg et al. / Bioorg. Med. Chem. 12 (2004) 1141–1149
1145
(dq, 1H, J=14.2 Hz, 7.1 Hz, CH2aCH3), 2.44 (dq,
5.9. General procedure for N-1alkylation of 4a,b
1H, J=14.2 Hz, 7.1 Hz, CH2bCH3), 3.48 (dq, 2H,
J=7.0 Hz, OCH2CH3), 4.82 (d, 1H, J=10.3 Hz,
NCH2aO), 5.30 (d, 1H, J=10.3 Hz, NCH2bO), 5.46
(s, 1H, C¼CH2a), 6.16 (s, 1H, C¼CH2b), 7.34–7.40
(m, 5H, Harom), 9.47 (s, 1H, NH). 13C NMR
(CDCl3): d 13.76 (CH3), 14.84 (CH3CH2O), 20.04
(CH2), 64.56 (CH3CH2O), 73.59 (NCH2O), 116.07
(C-5), 118.63 (=CH2), 125.39, 129.00, 129.05,
135.74 (Carom), 138.69 (C=CH2), 150.37 (C-6),
151.68 (C-2), 163.41 (C-4). HRMS (MALDI) m/z
calcd for C17H20N2O3Na+ (MNa+) 323.1366,
found 323.1369. Anal. calcd for C17H20N2O3: C,
67.98; H, 6.71; N, 9.33. Found: C, 67.93; H,
6.71; N, 9.18.
5.9.1. Method B. The pyrimidine 4a,b (1 mmol) was
suspended in dry acetonitrile (15 mL) under N2 and
N,O-bis(trimethylsilyl)acetamide (BSA) (0,87 mL, 3.5
mmol) was added. After a clear solution was obtained
(10 min), the reaction mixture was cooled to À45 ꢁC,
and TMS triflate (0.18 mL, 1 mmol) was added fol-
lowed by dropwise addition of the appropriate acetal
(2 mmol). The temperature was slowly increased to rt
and the reaction mixture stirred at rt overnight. (For
bis(2-propynyloxy)methane and bis(3-phenyl-2-pro-
pynyloxy)methane the reaction time was 3 days).
The reaction was quenched with cold satd. NaHCO3
(5 mL) and the solvent evaporated to near dryness
under reduced pressure. The residue was extracted
with CH2Cl2 (3ꢂ75 mL), and the combined organic
phases were dried (MgSO4) and evaporated under
reduced pressure yielding an oil, which was purified
by silica column chromatography to afford the pro-
duct using 2% MeOH/CH2Cl2 (10), chloroform (6–8,
12–14) or 25% EtOAc/Petroleum ether (9,11, 15–19)
as eluents.
5.7. 6-[1-(3,5-Dimethylphenyl)vinyl]-1-ethoxymethyl-5-
ethyl-1H-pyrimidine-2,4-dione (5b)
Yield: 78 mg (24%) as white crystals; mp 167–169 ꢁC; Rf
1
0.53 (EtOAc). H NMR (CDCl3): d 1.00 (t, 3H, J=7.3
Hz, CH2CH3), 1.07 (t, 3H, J=7.4 Hz, OCH2CH3),
2.14 (dq, 1H, J=14.6 Hz, 7.3 Hz, CH2aCH3), 2.31
(s, 6H, 2ꢂCH3), 2.44 (dq, 1H, J=14.6 Hz, 7.3 Hz,
CH2bCH3), 3.48–3.53 (m, 2H, OCH2CH3), 4.76 (d,
1H, J=10.1 Hz, NCH2aO), 5.32 (d, 1H, J=10.1
Hz, NCH2bO), 5.42 (s, 1H, C¼CH2a), 6.12 (s, 1H,
C¼CH2b), 6.97 (s, 2H, Harom), 6.98 (s, 1H, Harom), 9.45
(s, 1H, NH). 13C NMR (CDCl3): d 13.79 (CH3), 14.91
(CH3CH2O), 20.06 (CH2), 21.32 (2ꢂCH3), 64.61
(CH3CH2O), 73.61 (NCH2O), 115.93 (C-5), 118.33
(=CH2), 123.16, 130.81, 135.60, 138.60 (Carom), 138.70
(C=CH2), 150.73 (C-6), 151.74 (C-2), 163.51 (C-4).
HRMS (MALDI) m/z calcd for C19H25N2O+3 (MH+)
329.1859, found 329.1857, m/z calcd for (MNa+)
351.1679, found 351.1664. Anal. calcd for C19H24N2O3:
C, 69.49; H, 7.37; N, 8.53. Found: C, 69.36; H, 7.39; N,
8.51.
5.10. 1-Allyloxymethyl-5-ethyl-6-[1-(phenyl)vinyl]-1H-
pyrimidine-2,4-dione (6)
Yield: 253 mg (80%) as yellow crystals; mp 105–107 ꢁC;
Rf 0.32 (CHCl3). 1H NMR (CDCl3): d 0.99 (t, 3H,
J=7.5 Hz, CH2CH3), 2.16 (dq, 1H, J=15.0 Hz, 7.5 Hz,
CH2aCH3), 2.45 (dq, 1H, J=15.0 Hz, 7.5 Hz,
CH2bCH3), 3.00–4.03 (m, 2H, OCH2CH¼), 4.81 (d, 1H,
J=10.5 Hz, NCH2aO), 5.09–5.20 (m, 2H, C¼CH2), 5.35
(d, 1H, J=10.5 Hz, NCH2bO), 5.48 (s, 1H, C¼CH2a),
5.68–5.74 (m, 1H, CH), 6.16 (s, 1H, C¼CH2b), 7.27–
7.39 (m, 5H, Harom), 9.57 (s, 1H, NH). 13C NMR
(CDCl3): d 13.75 (CH3), 20.04 (CH2), 70.27 (CH2O),
73.38 (NCH2O), 116.29 (C-5), 117.29 (¼CH2), 118.82
(=CH2), 125.39, 129.05, 129.09 (Carom), 133.66
(CH=CH2), 135.66 (Carom), 138.58 (PhC¼CH2), 150.27
(C-6), 151.71 (C-2), 163.41 (C-4). HRMS (MALDI) m/z
calcd for C18H20N2O3Na+ (MNa+) 335.1366, found
5.8. 1-Ethoxymethyl-5-ethyl-6-[1-(naphthyl)vinyl]-1H-
pyrimidine-2,4-dione (5c)
Yield: 109 mg (31%) as white crystals; mp 58–60 ꢁC; Rf
335.1361. Anal. calcd for C18H20N2O3 0.25H2O: C,
68.23; H, 6.52; N, 8.84. Found: C, 68.42; H, 6.38; N,
8.85.
.
1
0.52 (EtOAc). H NMR (CDCl3): d 1.01 (t, 3H, J=7.0
Hz, CH2CH3), 1.09 (t, 3H, J=7.1 Hz, OCH2CH3), 2.37
(dq, 1H, J=14.0 Hz, 7.0 Hz, CH2aCH3), 2,63 (dq, 1H,
J=14.0 Hz, 7.0 Hz, CH2bCH3), 3.44 (q, 2H, J=7.1 Hz,
OCH2CH3), 4.83 (d, 1H, J=10.5 Hz, NCH2aO), 5.32 (d,
1H, J=10.5 Hz, NCH2bO), 6.00 (s, 1H, C¼CH2a), 6.09
(s, 1H, C¼CH2b), 7.24 (m, 1H, Hnaphthyl), 7.42 (t, 1H,
J=7.7 Hz, Hnaphthyl), 7.57 (m, 2H, Hnaphthyl), 7.84 (d,
1H, J=8.2 Hz, Hnaphthyl), 7.92 (d, 1H, J=7.7 Hz,
Hnaphthyl), 8.49 (d, 1H, J=8.2 Hz, Hnaphthyl), 9.34 (s,
1H, NH). 13C NMR (CDCl3): d 14.23 (CH3), 14.87
(CH3CH2O), 20.66 (CH2), 64.46 (CH3CH2O), 73.55
(NCH2O), 116.40 (C-5), 124.33, 124.96, 124.98, 125.43,
126.12, 127.03, 129.03, 129.24, 130.41, 134.35, 134.62
(¼CH2, 10ꢂCnaphthyl), 136.44 (C=CH2), 151.54, 151.84
(C-6, C-2), 163.52 (C-4). HRMS (MALDI) m/z calcd
for C21H22N2O3Na+ (MNa+) 373.1522, found
5.11. 5-Ethyl-1-(2-methylallyloxymethyl)-6-[1-(phenyl)-
vinyl]-1H-pyrimidine-2,4-dione (7)
Yield: 327 mg (99%) as yellow crystals; mp 104–105 ꢁC;
Rf 0.24 (CHCl3). 1H NMR (CDCl3): d 0.99 (t, 3H,
J=7.3 Hz, CH2CH3), 1.64 (s, 3H, CH3), 2.15 (dq, 1H,
CH2aCH3), 2.45 (dq, 1H, CH2bCH3), 3.92 (s, 2H,
CH2O), 4.77 (d, 1H, J=10.1 Hz, NCH2aO), 4.82, 4.85
(2ꢂs, 2H, C¼CH2), 5.34 (d, 1H, J=10.1 Hz, NCH2bO),
5.49 (s, 1H, C¼CH2a), 6.16 (s, 1H, C¼CH2b), 7.35–7.39
(m, 5H, Harom), 9.36 (br s, 1H, NH). 13C NMR
(CDCl3): d 13.76 (CH2CH3), 19.36 (CH3), 20.06 (CH2),
73.42 (OCH2), 73.60 (NCH2O), 112.14 (C(CH3)¼CH2),
116.05 (C-5), 118.89 (¼CH2), 125.40, 129.12,
129.09, 135.69 (Carom), 138.58 (C=CH2), 141.33
(C(CH3)¼CH2), 150.32 (C-6), 151.59 (C-2), 163.34 (C-
4). HRMS (MALDI) m/z calcd for C19H22N2O3Na+
.
373.1510. Anal. calcd for C21H22N2O3 0.25H2O: C,
71.07; H, 6.39; N, 7.89. Found: C, 71.29; H, 6.27; N,
7.92.

1146
M. Wamberg et al. / Bioorg. Med. Chem. 12 (2004) 1141–1149
(MNa+) 349.1522, found 349.1522. Anal. calcd for
.
C19H22N2O3 0.25H2O: C, 68.97; H, 6.85; N, 8.47.
Found: C, 69.07; H, 6.80; N, 8.49.
129.16, 135.49 (Carom), 138.12 (C=CH2), 150.12 (C-6),
151.79 (C-2), 163.37 (C-4). HRMS (MALDI) m/z calcd
for C18H18N2O3Na+ (MNa+) 333.1209, found
333.1206. Anal. calcd for C18H18N2O3 0.5H2O: C,
67.70; H, 6.00; N, 8.77. Found: C, 67.68; H, 5.86; N,
8.47.
.
5.12. 5-Ethyl-1-(3-methyl-2-butenyloxymethyl)-6-[1-
(phenyl)vinyl]-1H-pyrimidine-2,4-dione (8)
Yield: 162 mg (47%) as white crystals; mp 105–107 ꢁC;
Rf 0.37 (CHCl3). 1H NMR (CDCl3): d 1.00 (t, 3H,
J=7.3 Hz, CH2CH3), 1.62 (s, 3H, CH3), 1.70 (s, 3H,
CH3), 2.15 (dq, 1H, J=14.6 Hz, 7.3 Hz, CH2aCH3),
2.46 (dq, 1H, J=14.6 Hz, 7.3 Hz, CH2bCH3), 3.98 (d,
2H, J=7.0 Hz, CH2O), 4.74 (d, 1H, J=10.2 Hz,
NCH2aO), 5.14 (t, 1H, J=7.0 Hz, C¼CH), 5.34 (d, 1H,
J=10.2 Hz, NCH2bO), 5.49 (s, 1H, C¼CH2a), 6.15 (s,
1H, C¼CH2b), 7.34–7.39 (m, 5H, Harom), 9.31 (br s, 1H,
NH). 13C NMR (CDCl3): d 13.78 (CH2CH3), 17.97
(CH3), 20.03 (CH2), 25.73 (CH3), 65.74 (OCH2), 73.34
(NCH2O), 116.06 (C-5), 118.80 (¼CH2), 120.09 (¼
C(CH3)2), 125.38, 129.04, 135.71 (Carom), 137.63
(C¼C(CH3)2), 138.50 (C=CH2), 150.34 (C-6), 151.54
(C-2), 163.32 (C-4). HRMS (MALDI) m/z calcd for
C20H24N2O3Na+ (MNa+) 363.1679, found 363.1678.
5.15. 5-Ethyl-1-(3-phenyl-2-propynyloxymethyl-6-[1-
(phenyl)vinyl]-1H-pyrimidine-2,4-dione (11)
Yield: 39 mg (10%) as a colourless oil; Rf 0.08 (25%
1
EtOAc/Petroleum ether). H NMR (CDCl3): d 0.94 (t,
3H, J=7.5 Hz, CH2CH3), 2.12 (dq, 1H, J=15.0 Hz, 7.5
Hz, CH2aCH3), 2.44 (dq, 1H, J=15.0 Hz, 7.5 Hz,
CH2bCH3), 4.44 (d, 2H, ꢀCCH2O), 4.88 (d, 1H, J=10.5
Hz, NCH2aO), 5.51 (d, 1H, J=10.5 Hz, NCH2bO), 5.57
(s, 1H, C¼CH2a), 6.17 (s, 1H, C¼CH2b), 7.28–7.40 (m,
10H, Harom), 9.24 (s, 1H, NH). 13C NMR (CDCl3): d
13.66 (CH3), 20.05 (CH2), 57.84 (ꢀCCH2O), 73.47
(NCH2O), 84.46 (CH2Cꢀ), 86.35 (ꢀ CPh), 116.19 (C-5),
119.30 (¼CH2), 122.26 (ꢀC-Carom), 125.41, 128.29,
128.58 129.11, 129.14, 131.74, 135.55 (Carom), 138.18
(C=CH2), 150.20 (C-6), 151.69 (C-2), 163.18 (C-4).
HRMS (MALDI) m/z calcd for C24H22N2O3Na+
(MNa+) 409.1522, found 409.1507.
.
Anal. calcd for C20H24N2O3 0.25H2O: C, 69.64; H, 7.16;
N, 8.12. Found: C, 69.48; H, 7.06; N, 8.02.
5.13. 5-Ethyl - 1 - ((E) - 3 - phenylallyloxymethyl) - 6 - [1 -
(phenyl)vinyl]-1H-pyrimidine-2,4-dione (9)
5.16. 1-Allyloxymethyl-6-[1-(3,5-dimethylphenyl)vinyl]-5-
ethyl-1H-pyrimidine-2,4-dione (12)
Yield: 196 mg (49%) as white foam; mp 53–55 ꢁC; Rf
0.08 (25% EtOAc/Petroleum ether). 1H NMR (CDCl3):
d 1.01 (t, 3H, J=7.4 Hz, CH2CH3), 2.16 (dq, 1H,
J=14.8 Hz, 7.4 Hz, CH2aCH3), 2.47 (dq, 1H, J=14.8
Hz, 7.4 Hz, CH2bCH3), 4.17 (d, 2H, J=6.0 Hz, CH2O),
4.87 (d, 1H, J=10.1 Hz, NCH2aO), 5.39 (d, 1H, J=10.1
Hz, NCH2bO), 5.51 (s, 1H, C¼CH2a), 6.10 (td, 1H,
J=6.0 Hz, 15.9 Hz, PhCH¼CHCH2), 6.17 (s, 1H,
C¼CH2b), 6.50 (d, 1H, J=15.9 Hz, PhCH=CH), 7.24–
7.39 (m, 10H, Harom), 9.38 (s, 1H, NH). 13C NMR
(CDCl3): d 13.78 (CH3), 20.08 (CH2CH3), 69.91
(CH2O), 73.32 (NCH2O), 116.17 (C-5), 118.79 (¼CH2),
124.78, 125.43, 126.46, 127.75, 128.49, 129.07, 132.83,
135.67 (7ꢂCarom, CH¼), 136.43 (PhCH¼), 138.69
(C=CH2), 150.26 (C-6), 151.67 (C-2), 163.29 (C-4).
HRMS (MALDI) m/z calcd for C24H24N2O3Na+
(MNa+) 411.1679, found 411.1670. Anal. calcd for
Yield: 269 mg (77%) as a yellow solid; mp 133–134 ꢁC;
Rf 0.38 (CHCl3). 1H NMR (CDCl3): d 1.01 (t, 3H,
J=7.3 Hz, CH2CH3), 2.15 (dq, 1H, J=14.6 Hz, 7.3 Hz,
CH2aCH3), 2.32 (s, 6H, 2ꢂCH3), 2.46 (dq, 1H, J=14.6
Hz, 7.3 Hz, CH2bCH3), 4.04 (m, 2H, OCH2CH¼), 4.77
(d, 1H, J=10.2 Hz, NCH2aO), 5.17 (m, 2H, C¼CH2),
5.37 (d, 1H, J=10.2 Hz, NCH2bO), 5.44 (s, 1H,
C¼CH2a), 5.71–5.85 (m, 1H, CH), 6.13 (s, 1H,
C¼CH2b), 6.97 (s, 2H, Harom), 6.99 (s, 1H, Harom), 9.61
(s, 1H, NH). 13C NMR (CDCl3): d 13.79 (CH3), 20.05
(CH2), 21.31 (2ꢂCH3), 70.31 (CH2O), 73.41 (NCH2O),
116.00 (C-5), 117.20 (¼CH2), 118.51 (¼CH2), 123.16,
130.85, 133.75, 135.55 (Carom), 138.64 (2ꢂC¼CH2),
150.63 (C-6), 151.79 (C-2), 163.54 (C-4). HRMS
(MALDI) m/z calcd for C20H24N2O3Na+ (MNa+)
363.1679,
found
.
363.1675.
Anal.
calcd
for
C20H24N2O3 0.25H2O: C, 69.64; H, 7.16; N, 8.12.
Found: C, 69.91; H, 7.07; N, 8.15.
.
C24H24N2O3 0.5H2O: C, 72.52; H, 6.34; N, 7.05. Found:
C, 72.07; H, 5.92; N, 6.81.
5.17. 6-[1-(3,5-Dimethylphenyl)vinyl]-5-ethyl-1-(2-
methylallyloxymethyl)-1H-pyrimidine-2,4-dione (13)
5.14.
ymethyl)-1H-pyrimidine-2,4-dione (10)
5-Ethyl-6-[1-(phenyl)vinyl]-1-(2-propynylox-
Yield: 146 mg (41%) as off-white crystals; mp 139–
Yield: 67 mg (22%) as beige crystals; mp 125–127 ꢁC; Rf
0.32 (2% MeOH/CH2Cl2). 1H NMR (CDCl3): d 0.88 (t,
3H, J=7.5 Hz, CH2CH3), 2.04 (dq, 1H, J=15.0 Hz, 7.5
Hz, CH2aCH3) 2.29 (t, 1H, J=2.3 Hz, ꢀCH), 2.34 (dq,
1H, J=15.0 Hz, 7.5 Hz, CH2bCH3), 4.09 (s, 2H,
ꢀCCH2O), 4.69 (d, 1H, J=10.5 Hz, NCH2aO), 5.33 (d,
1H, J=10.5 Hz, NCH2bO), 5.42 (s, 1H, C¼CH2a), 6.05
(s, 1H, C¼CH2b), 7.15–7.28 (m, 5H, Harom), 9.44 (s, 1H,
NH). 13C NMR (CDCl3): d 13.77 (CH3), 20.03 (CH2),
57.09 (ꢀCCH2O), 73.39 (NCH2O), 74.51 (ꢀ CH), 79.13
(–Cꢀ),116.29 (C-5), 119.27 (¼CH2), 125.37, 129.11,
140 ꢁC; Rf 0.34 (CHCl3). H NMR (CDCl3): d 1.01 (t,
1
3H, J=7.5 Hz, CH2CH3), 1.66 (s, 3H, CH3), 2.14 (dq,
1H, J=15.0 Hz, 7.5 Hz, CH2aCH3), 2.32 (s, 6H,
2ꢂCH3), 2.45 (dq, 1H, J=15.0 Hz, 7.5 Hz, CH2bCH3),
3.94 (s, 2H, CH2O), 4.75 (d, 1H, J=10.1 Hz, NCH2aO),
4.83, 4.87 (2ꢂs, 2H, C¼CH2), 5.36 (d, 1H, J=10.1 Hz,
NCH2bO), 5.44 (s, 1H, C¼CH2a), 6.12 (s, 1H,
C¼CH2b), 6.96 (s, 2H, Harom), 6.99 (s, 1H, Harom), 9.34
(s, 1H, NH). 13C NMR (CDCl3): d 13.80 (CH2CH3),
19.36 (CH3), 20.08 (CH2), 21.33 (2ꢂCH3), 73.42
(OCH2), 73.63 (NCH2O), 112.08 (C(CH3)¼CH2),

M. Wamberg et al. / Bioorg. Med. Chem. 12 (2004) 1141–1149
1147
115.91 (C-5), 118.58 (¼CH2), 123.17, 130.87, 135.59,
138.64 (Carom), 138.64 (C=CH2), 141.40
J=15.0 Hz, 7.5 Hz, CH2aCH3) 2.32 (s, 6H, 2ꢂCH3),
2.42 (t, 1H, J=2.3 Hz, ꢀCH), 2.45 (dq, 1H, J=15.0 Hz,
7.5 Hz, CH2bCH3), 4.22 (d, 2H, J=2.3 Hz, ꢀCCH2O),
4.79 (d, 1H, J=10.3 Hz, NCH2aO), 5.46 (d, 1H, J=10.3
Hz, NCH2bO), 5.49 (s, 1H, C¼CH2a), 6.13 (s, 1H,
C¼CH2b), 6.97 (s, 2H, Harom), 7.00 (s, 1H, Harom), 9.24
(s, 1H, NH). 13C NMR (CDCl3): d 13.83 (CH3), 20.08
(CH2), 21.34 (2ꢂCH3), 57.17 (ꢀCCH2O), 73.48
(NCH2O), 74.45 (ꢀCH), 79.23 (–Cꢀ), 116.16 (C-5),
118.98 (¼CH2), 123.17, 130.95, 135.41, 138.74 (Carom),
138.24 (C=CH), 150.53 (C-6), 151.76 (C-2), 163.35 (C-
4). MS (MALDI) m/z calcd for C20H22N2O3Na+
(MNa+) 361.1522, found 361.1523. Anal. calcd for
C20H22N2O3: C, 70.99; H, 6.55; N, 8.28. Found: C,
71.07; H, 6.72; N, 8.14.
(C(CH3)¼CH2), 148.89 (C-6), 150.81 (C-2), 164.44 (C-
4). HRMS (MALDI) m/z calcd for C21H26N2O3Na+
(MNa+) 377.1835, found 377.1819. Anal. calcd for
.
C21H26N2O3 0.25H2O: C, 70.27; H, 7.44; N, 7.80.
Found: C, 70.53; H, 7.42; N, 7.81.
5.18. 6-[1-(3,5-Dimethylphenyl)vinyl]-5-ethyl-1-(3-
methyl-2-butenyloxymethyl)-1H-pyrimidine-2,4-dione
(14)
Yield: 240 mg (65%) as yellow crystals; mp 134–136 ꢁC;
Rf 0.40 (CHCl3). 1H NMR (CDCl3): d 1.00 (t, 3H,
J=7.3 Hz, CH2CH3), 1.62 (s, 3H, CH3), 1.71 (s, 3H,
CH3), 2.13 (dq, 1H, J=14.6 Hz, 7.3 Hz, CH2aCH3),
2.31 (s, 6H, 2ꢂCH3), 2.42 (dq, 1H, J=14.6 Hz, 7.3 Hz,
CH2bCH3), 3.99 (d, 2H, J=6.9 Hz, CH2O), 4.70 (d, 1H,
J=10.3 Hz, NCH2aO), 5.17 (t, 1H, J=6.9 Hz, C¼CH),
5.34 (d, 1H, J=10.3 Hz, NCH2bO), 5.44 (s, 1H,
C¼CH2a), 6.11 (s, 1H, C¼CH2b), 6.96 (s, 2H, Harom),
6.99 (s, 1H, Harom), 9.39 (s, 1H, NH). 13C NMR
(CDCl3): d 13.81 (CH2CH3), 17.97 (CH3), 20.05 (CH2),
21.31 (2ꢂCH3), 25.73 (CH3), 65.78 (OCH2), 73.36
(NCH2O), 115.93 (C-5), 118.50 (¼CH2), 120.20
(¼C(CH3)2), 123.15, 130.81, 135.59, 137.52 (Carom),
138.55 (C¼C(CH3)2), 138.62 (C=CH2), 150.68 (C-6),
151.63 (C-2), 163.48 (C-4). HRMS (MALDI) m/z calcd
for C22H28N2O3Na+ (MNa+) 391.1992, found
5.21. 6-[1-(3,5-Dimethylphenyl)vinyl]-5-ethyl-1-(3-phenyl-
2-propynyloxymethyl)-1H-pyrimidine-2,4-dione (17)
Yield: 42 mg (10%) as yellow crystals; mp 78 ꢁC; Rf 0.13
(25% EtOAc/Petroleum ether). 1H NMR (CDCl3): d
0.95 (t, 3H, J=7.5 Hz, CH2CH3), 2.13 (dq, 1H, J=15.0
Hz, 7.5 Hz, CH2aCH3), 2.44 (dq, 1H, J=15.0 Hz, 7.5
Hz, CH2bCH3), 4.45 (s, 2H, ꢀCCH2O), 4.85 (d, 1H,
J=10.5 Hz, NCH2aO), 5.52 (d, 1H, J=10.5 Hz,
NCH2bO), 5.52 (s, 1H, C¼CH2a), 6.14 (s, 1H,
C¼CH2b), 6.96 (s, 2H, Harom), 6.98 (s, 1H, Harom), 7.27–
7.41 (m, 5H, Harom), 9.24 (s, 1H, NH). 13C NMR
(CDCl3): d 13.71 (CH3), 20.09 (CH2), 21.29 (2ꢂCH3),
57.81 (ꢀCCH2O), 73.50 (NCH2O), 84.52 (CH2Cꢀ),
86.30 (ꢀCPh), 116.05 (C-5), 118.97 (¼CH2), 122.28
(ꢀC–Carom), 123.14, 128.29, 128.56 130.92, 131.72,
135.43, 138.72 (Carom), 138.23 (C¼CH2), 150.56 (C-6),
151.75 (C-2), 163.33 (C-4). HRMS (MALDI) m/z calcd
for C26H26N2O3Na+ (MNa+) 437.1836, found
437.1821.
.
391.1987. Anal. calcd for C22H28N2O3 0.25H2O: C,
70.85; H, 7.70; N, 7.51. Found: C, 70.90; H, 7.65; N,
7.61.
5.19. 6-[1-(3,5-Dimethylphenyl)vinyl]-5-ethyl-1-((E)-3-
phenylallyloxymethyl)-1H-pyrimidine-2,4-dione (15)
Yield: 117 mg (28%) as white foam; mp 56–57 ꢁC; Rf
0.10 (25% EtOAc/Petroleum ether). 1H NMR (CDCl3):
d 1.02 (t, 3H, J=7.3 Hz, CH2CH3), 2.16 (dq, 1H,
J=14.6 Hz, 7.3 Hz, CH2aCH3), 2.29 (s, 6H, 2ꢂCH3),
2.48 (dq, 1H, J=14.6 Hz, 7.3 Hz, CH2bCH3), 4.19 (d,
2H, J=6.1 Hz, CH2O), 4.84 (d, 1H, J=10.3 Hz,
NCH2aO), 5.41 (d, 1H, J=10.3 Hz, NCH2bO), 5.47 (s,
1H, C¼CH2a), 6.11 (m, 1H, PhCH=CHCH2), 6.14 (s,
1H, C¼CH2b), 6.52 (d, 1H, J=15.9 Hz, PhCH=CH),
6.97 (s, 3H, Harom), 7.24–7.36 (m, 5H, Harom), 9.50 (s,
1H, NH). 13C NMR (CDCl3): d 13.82 (CH3), 20.10
(CH2CH3), 21.34 (2ꢂCH3), 69.90 (CH2O), 73.31
(NCH2O), 116.17 (C-5), 118.79 (¼CH2), 124.78, 125.43,
5.22. 6-[1-(3,5-Dimethylphenyl)vinyl]-5-ethyl-1-((E)-3-
phenyl-2-methylallyloxymethyl)-1H-pyrimidine-2,4-dione
(18)
Yield: 214 mg (49%) as colourless foam; mp 53 ꢁC; Rf
0.12 (25% EtOAc/Petroleum ether). 1H NMR (CDCl3):
d 1.03 (t, 3H, J=7.2 Hz, CH2CH3), 1.81 (s, 3H, CH3),
2.17 (dq, 1H, J=14.4 Hz, 7.2 Hz, CH2aCH3), 2.30 (s,
6H, 2ꢂCH3), 2.48 (dq, 1H, J=14.4 Hz, 7.2 Hz,
CH2bCH3), 4.09 (s, 2H, CH2O), 4.82 (d, 1H, J=10.2
Hz, NCH2aO), 5.41 (d, 1H, J=10.2 Hz, NCH2bO), 5.49
(s, 1H, C¼CH2a), 6.14 (s, 1H, C¼CH2b), 6.40 (s, 1H,
C¼CH), 6.98 (s, 3H, Harom), 7.22–7.35 (m, 5H, Harom),
9.56 (s, 1H, NH). HRMS (MALDI) m/z calcd for
C27H30N2O3Na+ (MNa+) 453.2148, found 453.2146.
126.46, 127.75, 128.49, 129.07, 132.74, 135.54 (7ꢂCarom
,
CH¼), 136.45 (PhCH¼), 138.69 (C=CH2), 150.26 (C-
6), 151.76 (C-2), 163.46 (C-4). HRMS (MALDI) m/z
calcd for C26H28N2O3Na+ (MNa+) 439.1992, found
.
Anal. calcd for C27H30N2O3 0.25H2O: C, 74.54; H, 7.07;
N, 6.44. Found: C, 74.29; H, 6.93; N, 6.40.
.
439.1982. Anal. calcd for C26H28N2O3 0.25H2O: C,
74.17; H, 6.82; N, 6.65. Found: C, 74.22; H, 6.75; N,
6.59.
5.23. 6-[1-(3,5-Dimethylphenyl)vinyl]-5-ethyl-1-(indan-2-
yloxymethyl)-1H-pyrimidine-2,4-dione (19)
5.20. 6-[1-(3,5-Dimethylphenyl)vinyl]-5-ethyl-1-(2-propy-
nyloxymethyl)-1H-pyrimidine-2,4-dione (16)
Yield: 262 mg (63%) as a white powder; mp 163–165 ꢁC;
Rf 0.14 (25% EtOAc/Petroleum ether). 1H NMR
(CDCl3): d 1.00 (t, 3H, J=7.3 Hz, CH2CH3), 2.13 (dq,
1H, J=14.6 Hz, 7.3 Hz, CH2aCH3) 2.30 (s, 6H,
2ꢂCH3), 2.44 (dq, 1H, J=14.6 Hz, 7.3 Hz CH2bCH3),
Yield: 52 mg (15%) as a white powder; mp 116 ꢁC; Rf
0.08 (25% EtOAc/Petroleum ether). 1H NMR (CDCl3):
d 1.01 (t, 3H, J=7.5 Hz, CH2CH3), 2.13 (dq, 1H,

1148
M. Wamberg et al. / Bioorg. Med. Chem. 12 (2004) 1141–1149
2.81–3.11 (m, 4H, 2ꢂCH2), 4.45 (m, 1H, (CH2)2CHO),
4.80 (d, 1H, J=10.2 Hz, NCH2aO), 5.34 (s, 1H,
C¼CH2a), 5.41 (d, 1H, J=10.2 Hz, NCH2bO), 6.06 (s,
1H, C¼CH2b), 6.95 (s, 2H, Harom), 6.98 (s, 1H, Harom),
7.12–7.18 (m, 4H, Harom), 9.38 (s, 1H, NH). 13C NMR
(CDCl3): d 13.81 (CH3), 20.07 (CH2), 21.33 (2ꢂCH3),
39.03 (CH2), 39.46 (CH2), 72.20 (NCH2O), 78.42
((CH2)2CHO), 116.02 (C-5), 118.52 (¼CH2), 123.16,
124.53, 124.58, 126.48, 126.52, 130.82, 135.56, 138.61,
140.45, 140.61, (Carom), 138.47 (C¼CH2), 150.74 (C-6),
151.67 (C-2), 163.35 (C-4). HRMS (MALDI) m/z calcd
for C26H28N2O3Na+ (MNa+) 439.1992, found
439.1972. Anal. calcd for C26H28N2O3: C, 74.98; H,
6.78; N, 6.73. Found: C, 74.70; H, 6.81; N, 6.30.
4. Seki, M.; Sadakata, Y.; Yuasa, S.; Baba, M. Antiviral
Chem. Chemother. 1995, 6, 73.
5. Merluzzi, V. J.; Hargrave, K. D.; Labadia, M.; Grozinger,
K.; Skoog, M.; Wu, J. C.; Shih, C.-K.; Eckner, K.; Hat-
tox, S.; Adams, J.; Rosenthal, A. S.; Faanes, R.; Eckner,
R. J.; Koup, R. A.; Sullivan, J. L. Science 1990, 250, 1411.
6. Romero, D. L.; Olmsted, R. A.; Poel, T. J.; Morge, R. A.;
Biles, C.; Keiser, B. J.; Kopta, L. A.; Friis, J. M.; Hosley,
J. D.; Stefanski, K. J.; Wishka, D. G.; Evans, D. B.;
Morris, J.; Stehle, R. G.; Sharma, S. K.; Yagi, Y.; Voor-
man, R. L.; Adams, W. J.; Tarpley, W. G.; Thomas, R. C.
J. Med. Chem. 1996, 39, 3769.
7. Young, S. D.; Britcher, S. F.; Tran, L. O.; Payne, L. S.;
Lumma, W. C.; Lule, T. A.; Huff, J. R.; Anderson, P. S.;
Olsen, D. B.; Carroll, S. S.; Pettibone, D. J.; O’Brien,
J. A.; Ball, R. G.; Balani, S. K.; Lin, J. H.; Chen, I.-W.;
Schleif, W. A.; Sardana, V. V.; Long, W. J.; Byrnes, V. W.;
Emini, E. A. Antimicrob. Agents Chemother. 1995, 39,
2602.
6. Viruses and cells
8. Baba, M.; Tanaka, H.; De Clercq, E.; Pauwels, R.; Bal-
zarini, J.; Schols, D.; Nakashima, H.; Perno, C.-F.;
Walker, R. T.; Miyasaka, T. Biochem. Biophys. Res.
Commun. 1989, 165, 1375.
9. Miyasaka, T.; Tanaka, H.; Baba, M.; Hayakawa, H.;
Walker, R. T.; Balzarini, J.; De Clercq, E. J. Med. Chem.
1989, 32, 2507.
10. Yuasa, S.; Sadakata, Y.; Takashima, H.; Sekiya, K.;
Inouye, N.; Ubasawa, M.; Baba, M. Mol. Pharmacol.
1993, 44, 895.
11. Baba, M.; Shigeta, S.; Yuasa, S.; Takashima, H.; Sekiya,
K.; Ubasawa, M.; Tanaka, H.; Miyasaka, T.; Walker,
R. T.; De Clercq, E. Antimicrob. Agents Chemother. 1994,
38, 688.
The inhibitory activity against HIV-1 infection was
evaluated using MT-4 cells28 as target cells and the
HIV-1 strain HTLV-IIIB29 as infectious virus. The virus
was propagated in H928 cells at 37 ꢁC, 5% CO2 using
RPMI 1640 with 10% heat-inactivated fetal calf serum
(FCS) and antibiotics (growth medium). Culture super-
natant was filtered (0.45 nm), aliquoted, and stored at
À80 ꢁC until use.
6.1. Inhibition of HIV-1 replication
Compounds were examined for possible antiviral activ-
ity against both strains of HIV-1 using MT4 cells as
target cells. MT4 cells were incubated with virus
(0.005 MOI) and growth medium containing the test
dilutions of compounds for 6 days in parallel with virus-
infected and uninfected control cultures without com-
pound added. Expression of HIV in the cultures was
indirectly quantified using the MTT assay.30 Com-
pounds mediating less than 30% reduction of HIV
expression were considered without biological activity.
Compounds were tested in parallel for cytotoxic effect
in uninfected MT4 cultures containing the test dilutions
of compound as described above. A 30% inhibition of
cell growth relative to control cultures was considered
significant. The 50% inhibitory concentration (IC50)
and the 50% cytotoxic concentration (CC50) were
determined by interpolation from the plots of percent
inhibition versus concentration of compound. The test
for activity against HIV-1 was performed in MT-4 cell
cultures infected with either wild-type HIV-1(strain
IIIB30) or NNRTI resistant HIV-1 (strain N119,31 strain
A17,31b,32).
12. Tanaka, H.; Takashima, H.; Ubasawa, M.; Sekiya, K.;
Inouye, N.; Baba, M.; Shigeta, S.; Walker, R. T.; De
Clercq, E.; Miyasaka, T. J. Med. Chem. 1995, 38, 2860.
13. Hopkins, A. L.; Ren, J.; Tanaka, H.; Baba, M.; Okamato,
M.; Stuart, D. I.; Stammers, D. K. J. Med. Chem. 1999,
42, 4500.
14. Buckheit, R. W., Jr.; Watson, K.; Fliakas-Boltz, V.; Rus-
sell, J.; Loftus, T. L.; Osterling, M. C.; Turpin, J. A.;
Pallansch, L. A.; White, E. L.; Lee, J.-W.; Lee, S.-H.; Oh,
J.-W.; Kwon, H.-S.; Chung, S.-G.; Cho, E.-H. Anti-
microb. Agents Chemother. 2001, 45, 393.
15. Baba, M.; Tanaka, H.; Miyasaka, T.; Yuasa, S.; Uba-
sawa, M.; Walker, R. T.; De Clercq, E. Nucleosides
Nucleotides 1995, 14, 575.
16. Press statement from Triangle Pharmaceuticals Inc. 17th
of January 2002 http://www.tripharm.com
17. Szczech, G. M.; Furman, P.; Painter, G. R.; Barry, D. W.;
Borroto-Esoda, K.; Grizzle, T. B.; Blum, M. R.; Somma-
dossi, J.-P.; Endoh, R.; Niwa, T.; Yamamoto, M.; Mox-
ham, C. Antimicrob. Agents Chemother. 2000, 44, 123.
18. Merkatz, A. V. Ber. Dtsch. Chem. Ges 1919, 52, 869.
19. Son, J. C.; Lee, I. Y.; Bae, B. I.; Han, J. S.; Choi, J. K.;
Chae, Y. B. PCT Int. Appl. WO 95 18109, 1995.
20. Dolle, V.; Nguyen, C. H.; Legraverend, M.; Aubertin, A.-
M.; Kirn, A.; Andreola, M. L.; Ventura, M.; Tarrago-
Litvak, L.; Bisagni, E. J. Med. Chem. 2000, 43, 3949.
21. Boyd, R. E.; Rasmussen, C. R.; Press, J. B.; Raffa, R. B.;
Codd, E. E.; Connelly, C. D.; Li, Q. S.; Martinez, R. P.;
Lewis, M. A.; Almond, H. R.; Reitz, A. B. J. Med. Chem.
2001, 44, 863.
References and notes
1. Pedersen, O. S.; Pedersen, E. B. Antiviral Chem. Che-
mother. 1999, 10, 285.
2. Hopkins, A. L.; Ren, J.; Esnouf, R. M.; Willcox, B. E.;
Jones, E. Y.; Ross, C.; Miyasaka, T.; Walker, R. T.;
Tanaka, H.; Stammers, D. K.; Stuart, D. I. J. Med. Chem.
1996, 39, 1589.
3. Esnouf, R.; Ren, J.; Ross, C.; Jones, Y.; Stammers, D.;
Stuart, D. Nature Struct. Biol. 1995, 2, 303.
22. Danel, K.; Larsen, E.; Pedersen, E. B. Synthesis 1995, 934.
23. Vorbruggen, H.; Krolikiewicz, K.; Bennua, B. Chem. Ber.
1981, 114, 1234.
24. El-Brollosy, N. R.; Jørgensen, P. T.; Dahan, B.; Boel,
A. M.; Pedersen, E. B.; Nielsen, C. J. Med. Chem. 2002,
45, 5721.

M. Wamberg et al. / Bioorg. Med. Chem. 12 (2004) 1141–1149
1149
25. El-Brollosy, N. R.; Pedersen, E. B.; Nielsen, C. Arch.
Pharm. Pharm. Med. Chem. 2003, 336, 236.
26. Tanaka, H.; Takashima, H.; Ubasawa, M.; Sekiya, K.;
Nitta, I.; Baba, M.; Shigeta, S.; Walker, R. T.; De Clercq,
E.; Miyasaka, T. J. Med. Chem. 1992, 35, 337.
27. Nazaretyan, A. K.; Torosyan, G. O.; Babayan, A. T. J.
Appl. Chem. USSR 1985, 58, 2396.
30. Mosmann, T. J. Immunol. Methods 1983, 65, 55.
31. (a) Richman, D.; Shih, C. K.; Lowy, I.; Rose, J.; Proda-
novich, P.; Goff, S.; Griffin, J. Proc. Natl. Acad. Sci.
U.S.A. 1991, 88, 11241. (b) Hara, H.; Fujihashi, T.;
Sakata, T.; Kaji, A.; Kaji, H. AIDS Res. Hum. Retro-
viruses 1997, 13, 695.
32. Nunberg, J. H.; Schleif, W. A.; Boots, E. J.; O’Brien, J. A.;
Quintero, J. C.; Hoffman, J. M.; Emini, E. A.; Goldman,
M. E. J. Virol. 1991, 65, 4887.
28. Harada, S.; Koyanagi, Y.; Yamamoto, N. Science 1985,
229, 563.
29. Popovic, M.; Sarngadharan, M. G.; Read, E.; Gallo, R. C.
Science 1984, 224, 497.