Inhibitors interacting with the magnesium binding site of reverse transcriptase: Synthesis and biological activity studies of 3′-(Ω- amino-acyl) amino-3′-deoxy-thymidine

Article abstract of DOI:10.1080/15257770802088902

Active site of reverse transcriptase contains carboxylate groups involved in the magnesium binding. We prepared some nucleoside analogs which could bind to these carboxylates preventing the binding of nucleotides. To the 3′-amino-3′-deoxy-thymidine, different N-protected ω-amino-acids were bound, the protection removed to give the 3′-(ω-amino-acyl-) amino-3′-deoxy-thymidines in good yield. Some showed moderate to low activity in HIV 1 replication test. Copyright Taylor & Francis Group, LLC.

Full text of DOI:10.1080/15257770802088902

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Inhibitors Interacting with the
Magnesium Binding Site of Reverse
Transcriptase: Synthesis and Biological
Activity Studies of 3′-(Ω-Amino-Acyl)
Amino-3′-Deoxy-Thymidine
Thirumani Venkateshwar Goud a , Anne-Marie Aubertin b & Jean-
François Biellmann a
a Institute of Chemistry , Academia Sinica , Taipei, Taiwan
b Institut de Virologie , Strasbourg, France
Published online: 19 Jun 2008.
To cite this article: Thirumani Venkateshwar Goud , Anne-Marie Aubertin & Jean-François Biellmann
(2008) Inhibitors Interacting with the Magnesium Binding Site of Reverse Transcriptase: Synthesis and
Biological Activity Studies of 3′-(Ω-Amino-Acyl) Amino-3′-Deoxy-Thymidine, Nucleosides, Nucleotides
and Nucleic Acids, 27:5, 495-505, DOI: 10.1080/15257770802088902
To link to this article: http://dx.doi.org/10.1080/15257770802088902
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Nucleosides, Nucleotides and Nucleic Acids, 27:495–505, 2008
Copyright ꢀC Taylor & Francis Group, LLC
ISSN: 1525-7770 print / 1532-2335 online
DOI: 10.1080/15257770802088902
INHIBITORS INTERACTING WITH THE MAGNESIUM BINDING SITE
OF REVERSE TRANSCRIPTASE: SYNTHESIS AND BIOLOGICAL
ACTIVITY STUDIES OF 3ꢀ-(Ω-AMINO-ACYL) AMINO-3ꢀ-
DEOXY-THYMIDINE
Thirumani Venkateshwar Goud,1 Anne-Marie Aubertin,2 and
Jean-Franc¸ois Biellmann1
1Institute of Chemistry, Academia Sinica, Taipei, Taiwan
2Institut de Virologie, Strasbourg, France
Active site of reverse transcriptase contains carboxylate groups involved in the magnesium
2
binding. We prepared some nucleoside analogs which could bind to these carboxylates preventing
the binding of nucleotides. To the 3ꢁ-amino-3ꢁ-deoxy-thymidine, different N-protected ω-amino-acids
were bound, the protection removed to give the 3ꢁ-(ω-amino-acyl-) amino-3ꢁ-deoxy-thymidines in good
yield. Some showed moderate to low activity in HIV 1 replication test.
Keywords 3ꢁ-Amino-3ꢁ-deoxy-thymidine; magnesium binding site; reverse transcriptase;
kinases; HIV
INTRODUCTION
Magnesium ion is added in almost every test systems of phosphate
transferring enzymes, even if this ion has not been shown to be required
for the enzymatic activity.[1] It is not easy to demonstrate the precise role of
this ion in the phosphate transfer reaction. Due to its low molecular weight,
it does not show up like other heavy ions in the electronic density maps.
The absence of a concrete method like an x-ray structure determination
leaves the space open for mechanistic speculations. The order in which
magnesium ions are added to the enzyme in the reaction pathway is not
always determined. Does the phosphate ester bind to the enzyme before the
Received 11 October 2007; accepted 13 March 2008.
The authors are thankful to Prof. Nicolas Winssinger (ISIS, ULP, Strasbourg, France) for the
biological evaluation of the inhibition of kinases, and ANRS for financial support of the HIV tests. The
authors are also grateful to Prof. Sunney I. Chan for his encouragement.
Address correspondence to Jean-Franc¸ois Biellmann, Institute of Chemistry, Academia Sinica,
Taipei 115, Taiwan. or Anne-Marie Aubertin, Inserm U74, Institut de Virologie, 3 rue Koeberle67000,
Strasbourg, France. E-mail: An.Aubertin@viro-ulp.u-strasbg.fr
495

496
T. V. Goud et al.
magnesium ion to the enzyme? In a number of cases this has been shown to
occur. So the phosphate ester may bind to the enzyme without magnesium
ion. This has a certain implication for the rational design of inhibitors of
phosphate transferring enzymes. There are even kinases where magnesium
may not be involved in the binding nor in the catalysis.[1] With this fact
in mind, we looked at the structure of a number of phosphate transferring
enzymes and the first one was reverse transcriptase from HIV. Indeed this
enzyme catalyses at two active sites, two reactions involving phosphate esters:
polymerase and RNase.[2] In solution the binding of the substrate to the
RNase H domain is a precondition for metal ion binding.[3] In RNase active
site four acidic residues are located: Asp443, Glu478, Asp498, and Asp549. In the
polymerase site three Asp110, Asp185, and Asp186 bind magnesium ions.[4–6]
The resistance of a zwitterionic RNA to the exonuclease has its origin
to the binding of the ammonium of 3-amino-propyl group at C-2ꢁ to the
metal binding site, interfering with the phosphoryl transfer.[7] This induced
the design of nucleoside analogs bearing a group binding to the carboxylic
groups present in the active site. Their binding interferes on the subsequent
binding of magnesium ion. As group binding to the carboxylate residues we
chose the primary amine of a ω-amino-acyl chain. This chain is bound at C-3ꢁ
through an amide as in structure of puromycin, an antibiotic which inhibits
the protein synthesis by substituting the incoming aminoacyl-tRNA.[8,9] This
group of puromycin seems to be stable under physiological conditions and
we inferred that the same holds for other amides at C-3ꢁ.
RESULTS AND DISCUSSION
Procedure
3ꢁ-Amino-3ꢁ-deoxy-thymidine (6) have been prepared as described
previously.[10.11] The carbobenzoxyamino acids a–h have been condensed
with the amine 6 in the presence of HBTU and diisopropylethylamine to
give amides 7a–7h in 60–70% yield (Schemes 1 and 2). The hydrogenolysis
was performed with hydrogen in presence of Pd/C and the free amines
8a–8h were obtained as solids in a yield of 60–80%. Their spectral data
correspond to the proposed structure. The acids were racemates and thus
the compounds 8f and 8g were obtained as diastereoisomers even if their
NMR spectra did not show any sign of heterogeneity. We did not try to
separate them.
Anticancer Activity
The anticancer properties of compounds 8a, 8c and 8g were studied un-
der the developmental program of the National Cancer Institute NCI/NIH.
Results obtained indicated that at a concentration of 10−5 M, compounds 8c

3ꢁ-(ꢀ-Amino-acyl) Amino-3ꢁ-deoxy-thymidine
497
SCHEME 1 Synthesis of amino-3ꢁ-deoxy-thymidine 6 and of carbobenzoxyamino acids a–h.
and 8g showed total inhibition of strain HCC-2998 of colon cancer, whereas
8a did not show positive result.
Inhibition of HIV-1 Replication
Nucleoside analogs 8a–8h were studied for anti-HIV-1 activity on CEM-SS
infected by HIV-1 Lai[12] (Table 1). Compound 8a had a modest antiviral

498
T. V. Goud et al.
SCHEME 2 Synthesis of 3ꢁ-(ω-amino-acyl)-3ꢁ-deoxy-thymidine.
activity (IC50 = 660 µM), while compounds 8c and 8f showed little activity
but the IC50 was close to the CC50 cytotoxic concentrations, thus the
selectivity indexes were low (2–4 CC50/IC50) (Table 1). Compound 8e had a
selectivity index of 1 CC50/IC50 (Table 1). On MT4 cells, no specific antiviral
activity was measurable (Table 1).
Inhibition on a Panel of Kinases
Compounds 6, 8a, 8b, 8d, 8e, 8f, and 8g were tested for their inhibition
on a panel of kinases. The panel of kinases included AKT1, ARK5, Aurora-
A, Aurora-B, B-RAF-VE, CDK2/CycA, CDK4/CycD1, COT, FAK, EPHB4,
ERBB2, EGF-R, IGF1-R, SRC, VEGF-R2, VEGF-R3, FLT3, INS-R, MET,
PDGFR-beta, PLK1, SAK, TIE2, and CK2-alpha1. Data obtained showed

3ꢁ-(ꢀ-Amino-acyl) Amino-3ꢁ-deoxy-thymidine
499
TABLE 1 Anti-HIV Activity on HIV-1 Lai wild type in CEM-SS
HIV-1 LAI CEM-SS
IC50 (µM)a CC50(µM)b
HIV-1 IIIB MT4
Compound
IC50 (µM)
CC50(µM)
6
20
660
500
>103
>103
660
>CC50
>CC50
>CC50
>1.103
>5.102
>CC50
>CC50
>500
2.3
150
780
8a
8b
8c
8d
8e
8f
8g
8h
AZT
>103
390
>1.103
>5.102
24
>5.102
150
>5.102
160
60
220
22
>5.102
240
>5.102
8−70
>500
6−90
>CC50
2.1 10−3
1.9.10−2
aIC50 : 50% inhibitory concentration or concentration required to inhibit the
replication of HIV by 50%;
bCC50 : cytotoxic concentration or concentration required to reduce the viability
of uninfected cell by 50%.
that all the above mentioned compounds were found to be inactive at a
concentration of 10 µM.[13]
CONCLUSION
Some of the 3ꢁ-(ω-amino-acyl) amino-3ꢁ-deoxy-thymidine derivatives
were found to exhibit low activity in HIV-1 replication test. Whether this is
due to the inhibition of the reverse transcriptase remains an open question.
The cytotoxic effects observed with some compounds were not reflected
in the results of the anticancer trials, but those trials were done at lower
concentration. None of the kinases were significantly inhibited with these
thymidine derivatives, which may not be too surprising since the attachment
is at C-3ꢁ. Finally the question raised with these results is: Is the amide
group a proper attachment of the side chain bearing the group interacting
with the carboxylate groups Some analogs with chain bearing amino group
linked at C-3ꢁ by a ether had been reported as inactive against Herpes virus
and HIV.[14,15] The presence of hydrophobic group in 8f and 8h gives an
indication for the design of new analogs as well as the fact in 8c and 8h the
distance between the amide and the amino group is a C5 and C6 chain. It
would be interesting to determine the activity of the products with ether as
link at C-3ꢁ and the C6 chain.
EXPERIMENTAL
General Procedure
All the reactions were carried out under an atmosphere of nitrogen.
Melting points (mp) were taken on a MEL-TEMP capillary tube apparatus

500
T. V. Goud et al.
1
and are uncorrected. H NMR and 13C NMR spectra were recorded in d4-
MeOH solution using Bruker 400 or 500 MHz.
2H4-MeOH instrument and chemical shifts were reported using d4-
MeOH (49.1 ppm) as 2H4-MeOH internal standards. Purification by column
chromatography was carried out with neutral silica gel 60 (70–230 mesh
ASTM). MS spectra were determined on a Shimadzu QP-1000 spectrometer
or VG 70–250S spectrometer. HRMS spectra were collected on Autospec
orthogonal acceleration-time of flight mass spectrometer with a resolution
of 6000 (5%). All the starting materials are purchased from Aldrich.
<aq>Please provide names and locations for manufacturers used and
mentioned</aq>
General Procedure for the Preparation of 3ꢁ-[(N-benzyloxycarbonyl
-amino acids)-amino] -3ꢁ-deoxy-thymidine (7a–7h.
3ꢁ- Amino thymidine (6)11 (100 mg, 1 equiv.), corresponding N-
benzyloxycarbonyl-amino acid (1 equiv.), and HBTU (1.1 equiv.), were
dissolved in dry DMF (3 ml) under nitrogen with a syringe, after few
minutes diisopropyl ethyl amine (DIEA) (2 equiv.) was added to the reaction
mixture. The reaction mixture was stirred at room temperature for 3 hours.
The solvents were evaporated under vacuum, and the crude residue was
purified by flash column chromatography (gradient EtOAc—MeOH).
3ꢁ-[(N-benzyloxycarbonyl-glycyl)-amino]-3ꢁ-deoxy-thymidine
(7a). Com-
1
pound 7a obtained as fluffy white solid. Yield (0.120 g, 67%), H NMR
(d4-MeOH, 500 MHz): δ 1.86 (s, 3H), 2.32 (m, 2H), 3.69 (m, 1H), 3.72 (br
m, 2H), 4.51 (m, 1H), 5.08 (s, 2H), 6.19 (t, 1H, J = 4.2 Hz), 7.27—7.35
(m, 5H), 7.85 (s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ 12.4 (CH3), 38.5
(CH2), 44.8 (CH2), 49.7 (CH), 62.3 (CH2), 67.8 (CH2), 85.8 (CH), 86.3
(CH), 111.4 (C), 129.0 (CH), 129.1 (CH), 129.4 (CH), 138.0 (CH), 138.0
(C), 152.0 (C), 159.0 (C), 166.3 (C), 172.3 (C). Mass spectrum (FABMS):
m/z 433 (M+H)+; exact mass calcd. for C20H25N4O7 433.1268, found
433.1262.
3ꢁ-[(N-benzyloxycarbonyl-β−alanyl)amino]-3ꢁ-deoxy-thymidine (7b). Com-
1
pound 7b obtained as fluffy white solid. Yield (0.145 g, 78.3%), H NMR
(d4-MeOH, 500 MHz): δ 1.85 (s, 3H), 2.25 (m, 2H), 2.40 (t, 1H, J = 6.8
Hz), 3.38 (t, 1H, J = 6.8 Hz), 3.71 (m, 1H), 3.82 (m, 2H), 4.52 (m, 1H),
5.0 (s, 2H), 6.18 (t, 1H, J = 4.2 Hz), 7.28 (m, 5H), 7.82 (s, 1H). 13C NMR
(d4-MeOH, 125 MHz): δ 13.0 (CH3), 37.6 (CH2), 38.8 (CH2), 39.1 (CH2),
49.7 (CH), 62.8 (CH2), 67.8 (CH2), 86.2 (CH), 86.9 (CH), 111.9 (C), 129.2
(CH), 129.4 (CH), 129.8 (CH), 138.5 (CH), 138.6 (C), 152.7 (C), 159.1 (C),
166.7 (C), 174.3 (C). Mass spectrum (FABMS): m/z 447 (M+H)+; exact mass
calcd. for C21H27N4O7 447.1801 found 447.1794.
3ꢁ-[(N-benzyloxycarbonyl-amino-γ -butyryl)amino]-3ꢁ-deoxy-thymidine (7c).
Compound 7c obtained as off-white solid. Yield (0.145 g, 76.3%), 1H NMR

3ꢁ-(ꢀ-Amino-acyl) Amino-3ꢁ-deoxy-thymidine
501
(d4-MeOH, 500 MHz): δ 1.76 (m, 2H), 1.86 (s, 3H), 2.27 (t, 2H, J = 6.0
Hz), 3.13 (t, 2H, J = 5.2 Hz), 3.70 (m, 1H), 3.83 (m, 2H), 4.45 (m, 1H),
5.0 (s, 2H), 6.20 (t, 1H, J = 4.8 Hz), 7.29 (m, 5H), 7.84 (s, 1H). 13C NMR
(d4-MeOH, 125 MHz): δ 12.4 (CH3), 27.0 (CH2), 34.0 (CH2), 38.6 (CH2),
41.2 (CH2), 50.2 (CH), 62.4 (CH2), 67.4 (CH2), 85.8 (CH), 86.5 (CH),
111.5 (C), 128.7 (CH), 128.9 (CH), 129.4 (CH), 138.0 (CH), 138.3 (C),
152.2 (C), 158.8 (C), 166.3 (C), 175.6 (C). Mass spectrum (FABMS): m/z
461 (M+H)+; exact mass calcd. for C22H29N4O7 461.1958 found 461.1952.
3ꢁ-[(N-benzyloxycarbonyl-amino-δ−valeryl)amino]-3ꢁ-deoxy-thymidine (7d).
1
Compound 7d obtained as fluffy white solid. Yield (0.180 g, 91.8%), H
NMR (d4-MeOH, 500 MHz): δ 1.48 (m, 2H), 1.62 (m, 2H), 1.86 (s, 3H),
2.23 (t, 2H, J = 7.2 Hz), 2.32 (m, 2H), 3.11 (t, 2H, J = 6.8 Hz), 3.72 (m,
1H), 3.84 (m, 2H), 4.47 (m, 1H), 5.0 (s, 2H), 6.20 (t, 1H, J = 6.0 Hz), 7.28
(m, 5H), 7.84 (s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ 12.5(CH3), 24.0
(CH2), 30.3 (CH2), 37.0 (CH2), 38.7 (CH2), 41.4 (CH2), 50.2 (CH), 62.5
(CH2), 67.3 (CH2), 85.9 (CH), 86.5 (CH), 111.5 (C), 128.7 (CH), 128.9
(CH), 129.5 (CH), 138.2 (CH), 138.4 (C), 152.3 (C), 158.8 (C), 166.4 (C),
176.0 (C). Mass spectrum (FABMS): m/z 475 (M+H)+; exact mass calcd. for
C23H31N4O7 475.2114 found 475.2109.
3ꢁ- [(N-benzyloxycarbonyl-amino-ε-hexanoyl)amino]-3ꢁ-deoxy-thymidine (7e).
Compound 7e obtained as fluffy white solid. Yield (0.123 g, 81.4%), 1H NMR
(d4-MeOH, 500 MHz): δ 1.32 (m, 2H), 1.50 (m, 2H), 1.62 (m, 2H), 1.86 (s,
3H), 2.19 (m, 2H), 2.26—2.32 (m, 2H), 3.0 (m, 2H), 3.73 (m, 1H), 3.85 (m,
2H), 4.48 (m, 1H), 5.0 (s, 2H), 6.20 (t, 1H, J = 6.0 Hz), 7.26 (m, 5H), 7.82
(s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ 12.5 (CH3), 26.5 (CH2), 27.3
(CH2), 30.5 (CH2), 36.8 (CH2), 38.7 (CH2), 41.6 (CH2), 50.3 (CH), 62.6
(CH2), 67.3 (CH2), 85.9 (CH), 86.6 (CH), 111.5 (C), 128.7 (CH), 128.9
(CH), 129.4 (CH), 138.0 (CH), 138.4 (C), 152.3 (C), 158.8 (C), 166.3 (C),
176.2 (C). Mass spectrum (FABMS): m/z 489 (M+H)+; exact mass calcd. for
C24H33N4O7 489.2305 found 489.2298.
3ꢁ-(N-benzyloxycarbonyl-dl-phenylalanyl)amino-3ꢁ-deoxy-thymidine
(7f).
1
Compound 7f obtained as off-white solid. Yield (0.142 g, 65.7%), H NMR
(d4-MeOH, 500 MHz): δ 1.85 (s, 3H), 2.20 (m, 2H), 2.27 (m, 1H), 2.95 (m,
1H), 3.03 (m, 2H), 3.29 (m, 1H) 3.55—3.69 (m, 2H), 4.30 (m, 1H), 4.33
(m, 1H), 5.0 (s, 2H), 6.11 (t, 1H, J = 6.0 Hz), 7.18—7.29 (m, 10 H), 7.78
(s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ 12.4 (CH3), 38.4 (CH2), 39.4
(CH2), 50.0 (CH), 58.0 (CH), 62.3 (CH2), 67.6 (CH2), 85.9 (CH), 86.1
(CH), 111.5 (C), 127.9 (CH), 128.9 (CH), 129.5 (CH), 129.54 (CH), 130.4
(CH), 138.1 (CH), 138.4 (CH), 152.2 (C), 158.4 (C), 166.3 (C), 174.0 (C),
174.1 (C). Mass spectrum (FABMS): m/z 523 (M+H)+; exact mass calcd.
for C27H31N4O7 523.2114 found 523.2110.
3ꢁ-(N-benzyloxycarbonyl-β-phenyl-β-dl-alanyl)amino-3ꢁ-deoxy-thymidine (7g).
Compound 7g obtained as off-white solid. Yield (0.130 g, 60.1%), 1H NMR
(d4-MeOH, 500 MHz): δ 1.86 (s, 3H), 2.20—2.28 (m, 2H), 2.49 (m, 1H),

502
T. V. Goud et al.
2.62 (m, 1H), 2.89 (m, 1H), 3.61 (m, 1H), 3.77 (m, 2H) 4.33 (m, 1H), 4.41
(m, 1H), 5.01 (s, 2H), 6.13 (s, 1H), 7.18—7.31 (m, 10 H), 7.81 (s, 1H). 13C
NMR (d4-MeOH, 125 MHz): δ 12.4 (CH3), 38.7 (CH2), 38.8 (CH2), 45.6
(CH2), 50.1 (CH), 54.4 (CH), 62.3 (CH2), 85.9 (CH), 86.2 (CH), 111.5 (C),
127.6 (CH), 128.2 (CH), 129.4 (CH), 129.5 (CH), 129.7 (CH), 138.1 (CH),
142.0 (CH), 144.7 (CH), 152.3 (C), 164.9 (C), 173.5 (C), 175.3 (C). Mass
spectrum (FABMS): m/z 523 (M+H)+; exact mass calcd. for C27H31N4O7
523.2114 found 523.2107.
3ꢁ-(N-benzyloxycarbonyl-4-aminomethylbenzoyl)
amino-3ꢁ-deoxy-thymidine
(7h). Compound 7h obtained as fluffy white solid. Yield (0.050 g, 68.5%),
mp 180–185 ◦C, 1H NMR (d4-MeOH, 500 MHz): δ 1.88 (s, 3H), 2.42—2.44
(m, 2H), 3.78 (dd, 1H, J = 3.5 Hz), 3.86 (dd, 1H, J = 3.5 Hz), 4.0 (m, 1H),
4.33 (s, 2H), 4.68 (m, 1H), 6.26 (t, 1H, J = 5.2 Hz), 7.32—7.36 (m, 7H),
7.77 (d, 2H, J = 8.5 Hz), 7.88 (s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ
12.5 (CH3), 38.9 (CH2), 44.5 (CH2), 50.7 (CH), 62.5 (CH2), 67.7 (CH2),
86.1 (CH), 86.4 (CH), 111.6 (C), 128.3 (CH), 128.7 (CH), 128.8 (CH),
129.0 (CH), 129.5 (CH), 134.0 (C), 138.3 (CH), 145.0 (C), 152.4 (C), 159.1
(C), 166.5 (C), 170.2 (C). Mass spectrum (FABMS): m/z 509 (M+H)+;
exact mass calcd. for C26H29N4O7 509.1958 found 509.1951.
General Procedure for the Preparation of 3ꢁ-[(Amino acids)-amino]
-3‘-deoxy-thymidine (8a–8h)
Substrates (7a–7h) (100 mg) were dissolved in EtOH (10 ml), followed
by 10% palladium on charcoal (70 mg) was exposed to a positive pressure
of hydrogen gas at room temperature for overnight. The reaction mixture
was filtered through celite pad that was successively washed with DCM and
ethanol. Solvents were removed under vacuum from the combined filtrates
to afford compounds 8a–8h as white solids.
3ꢁ-glycylamino-3ꢁ-deoxy-thymidine (8a). Compound 8a obtained as white
◦
1
solid. Yield (0.078 g, 63.4%), mp 140–145 C, H NMR (d4-MeOH, 500
MHz): δ 1.84 (s, 3H), 2.30 (m, 2H), 3.70 (m, 1H), 3.82 (m, 2H), 4.48
(m, 1H), 6.19 (s, 1H), 7.84 (s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ
12.5 (CH3), 38.8(CH2), 44.7 (CH2), 48.7 (CH), 62.4 (CH2), 85.1 (CH),
85.5 (CH), 111.5 (C), 138.2 (CH), 152.4 (C), 166.5 (C), 174.6 (C). Mass
spectrum (FABMS): m/z 299 (M+H)+; exact mass calcd. for C12H19N4O5
299.1268, found 299.1262.
3ꢁ-β-alanylamino-3ꢁ-deoxy-thymidine (8b). Compound 8b obtained as
◦
1
white solid. Yield (0.089 g, 88.1%), mp 135–140 C, H NMR (d4-MeOH,
500 MHz): δ 1.83 (s, 3H), 2.30 (m, 2H), 2.37 (t, 2H, J = 6.4 Hz), 2.89 (t,
2H, J = 6.4 Hz), 3.69 (m, 1H), 3.81 (m, 2H), 4.45 (m, 1H), 6.17 (t, 1H,
J = 4.2 Hz), 7.82 (s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ 13.0 (CH3),
39.1 (CH2), 39.15 (CH2), 39.2 (CH2), 50.7 (CH), 62.9 (CH2), 86.3 (CH),
86.9 (CH), 111.9 (C), 138.5 (CH), 153.0 (C), 167.1 (C), 174.7 (C). Mass

3ꢁ-(ꢀ-Amino-acyl) Amino-3ꢁ-deoxy-thymidine
503
spectrum (FABMS): m/z 313 (M+H)+; exact mass calcd.for C13H21N4O5
313.1434 found 313.1426.
3ꢁ-(γ -amino-butyryl)amino-3ꢁ-deoxy-thymidine (8c). Compound 8c ob-
◦
tained as white solid. Yield (0.098 g, 72.5%), mp 110–115 C, 1H NMR
(d4-MeOH, 500 MHz): δ 1.77 (m, 2H), 1.87 (s, 3H), 2.25—2.34 (m, 4H),
2.67 (m, 2H), 3.70 (m, 1H), 3.85 (m, 2H), 4.47 (m, 1H), 6.21 (t, 1H, J = 4.2
Hz), 7.84 (s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ 12.5 (CH3), 28.9 (CH2),
34.2 (CH2), 38.6 (CH2), 41.6 (CH2), 50.2 (CH), 62.4 (CH2), 84.5 (CH),
85.0 (CH), 111.5 (C), 138.0 (CH), 152.8 (C), 167.0 (C), 175.7 (C). Mass
spectrum (FABMS): m/z 327 (M+H)+; exact mass calcd. for C14H23N4O5
327.1668 found 327.1673.
3ꢁ-(δ-aminovaleryl)amino-3ꢁ-deoxy-thymidine (8d). Compound 8d ob-
tained as white solid. Yield (0.100 g, 76.9%), mp 170–175 ◦C, 1H NMR (D2O,
500 MHz): δ 1.68 (m, 4H), 1.92 (s, 3H), 2.36—2.44 (m, 4H), 2.94 (m, 2H),
3.77 (m, 1H), 3.88 (m, 1H), 4.0 (br s, 1H), 4.50 (m, 1H), 6.30 (s, 1H), 7.63
(s, 1H). 13C NMR (D2O 125 MHz): δ 12.3(CH3), 22.2 (CH2), 27.3 (CH2),
34.9 (CH2), 36.4 (CH2), 39.3 (CH2), 48.8 (CH), 61.0 (CH2), 83.8 (CH),
84.6 (CH), 111.6 (C), 136.6 (CH), 156.5 (C), 173.0 (C), 176.2 (C). Mass
spectrum (FABMS): m/z 341 (M+H)+; exact mass calcd. for C15H25N4O5
341.1825 found 341.1830.
3ꢁ-(δ-aminohexanoyl)amino-3ꢁ-deoxy-thymidine (8e). Compound 8e ob-
tained as white solid. Yield (0.078 g,), mp 115–120 ◦C, 1H NMR (d4-MeOH,
500 MHz): δ 1.35 (m, 2H), 1.52 (m, 2H), 1.62 (m, 2H), 1.87 (s, 3H), 2.22
(m, 2H), 2.27—2.31 (m, 2H), 3.72 (m, 1H), 3.86 (m, 2H), 4.48 (m, 1H),
6.21 (t, 1H, J = 6.0 Hz), 7.84 (s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ
12.6 (CH3), 26.6 (CH2), 27.4 (CH2), 32.0 (CH2), 38.8 (CH2), 41.9 (CH2),
50.3 (CH), 62.5 (CH2), 85.9 (CH), 86.5 (CH), 111.6 (C), 138.1 (CH), 128.9
(CH), 152.9 (C), 167.2 (C), 176.2 (C). Mass spectrum (FABMS): m/z 355
(M+H)+; exact mass calcd. for C16H27N4O5 355.1981 found 355.1983.
3ꢁ- dl-phenylalanylamino-3ꢁ-deoxy-thymidine (8f). Compound 8f obtained
as white solid. Yield (0.085 g, 64.8%), mp 90–95 ◦C, 1H NMR (d4-MeOH, 500
MHz): δ 1.86 (s, 3H), 2.30 (m, 2H), 2.92 (m, 2H), 3.54 (m, 1H), 3.65 (m,
1H), 3.78 (m, 1H), 4.41 (m, 1H), 4.62 (m, 1H), 6.10 (s, 1H), 7.25 (m, 5H),
7.78 (s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ 12.4 (CH3), 38.6 (CH2),
42.8 (CH2), 50.0 (CH), 57.8 (CH), 62.4 (CH2), 85.9 (CH), 86.1 (CH), 111.5
(C), 127.8 (CH), 129.6 (CH), 130.5 (CH), 138.2 (CH), 138.8 (C), 152.4 (C),
166.5 (C), 176.8 (C). Mass spectrum (FABMS): m/z 389 (M+H)+; exact mass
calcd. for C19H25N4O5 389.1825 found 389.1824.
3ꢁ-(β-amino-β-phenyl-dl-alanyl) amino-3ꢁ-deoxy-thymidine (8g). C◦ompo-
1
und 8g obtained as white solid. Yield (0.075 g, 57.1%), mp 95–100 C, H
NMR (d4-MeOH, 500 MHz): δ 1.87 (s, 3H), 2.19—2.27 (m, 2H), 2.58 (m,
1H), 2.62 (m, 1H), 2.90 (m, 1H), 3.60 (m, 1H), 3.77 (m, 2H) 4.33 (br s,
1H), 4.41 (m, 1H), 6.12 (t, 1H, J = 6.0 Hz), 7.14—7.31 (m, 5H), 7.81 (s,
1H). 13C NMR (d4-MeOH, 125 MHz): δ 12.5 (CH3), 38.7 (CH2), 45.6 (CH2),

504
T. V. Goud et al.
50.1 (CH), 54.5 (CH), 62.3 (CH2), 86.0 (CH), 86.5 (CH), 111.5 (C), 127.6
(CH), 129.5 (CH), 129.7 (CH), 138.1 (CH), 142.0 (C), 152.3 (C), 164.9 (C),
173.5 (C). Mass spectrum (FABMS): m/z 389 (M+H)+; exact mass calcd. for
C19H25N4O5 389.1829 found 389.1825.
3ꢁ-(4-aminomethyl-benzoyl) amino-3ꢁ-deoxy-thymidine (8h). Compound 8h
obtained as white solid. Yield (0.030 g, 83.0%), mp 85–90 ◦C, 1H NMR (d4-
MeOH, 500 MHz): δ 1.89 (s, 3H), 2.42 (s, 2H), 2.46 (m, 2H), 3.78 (dd, 1H,
J = 3.5 Hz), 3.88 (dd, 1H, J = 3.5 Hz), 4.0 (m, 1H), 4.72 (m, 1H), 6.27
(t, 1H, J = 6.0 Hz), 7.26 (d, 2H, J = 8.0 Hz), 7.72 (d, 2H, J = 8.0 Hz),
7.89 (s, 1H). 13C NMR (d4-MeOH, 125 MHz): δ 12.5 (CH3), 38.7 (CH2),
43.0 (CH2), 50.6 (CH), 62.5 (CH2), 86.1 (CH), 86.4 (CH), 111.6 (C), 128.5
(CH), 130.2 (CH), 132.4 (C), 138.3 (CH), 143.7 (C), 152.4 (C), 166.5 (C),
170.5 (C). Mass spectrum (FABMS): m/z 375 (M+H)+; exact mass calcd. for
C18H22N4O5 375.1590 found 375.1587.
Biological Evaluation of the Antiviral Activity of the Compounds. The
effects of the compounds on the replication of HIV-1 were evaluated as
previously described.[12]
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3ꢁ-(ꢀ-Amino-acyl) Amino-3ꢁ-deoxy-thymidine
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