949
3’-(4-Nitroimidazol- 1-yl)-2’,3’-dideoxynucleosides
Synthesis of 3’-(4-Nitroimidazol-l-yl)-2’,3’-dideoxynucleosidesof Pyrimidine Analogues and their Biological Evaluation against HIV Mohammed S. Motawia and Erik B. Pedersen* Department of Chemistry, Odense University, Campusvej 55,DK-5230 Odense, M, Denmark
Jerzy Suwinski Institute of Organic Chemistry and Technology, Silesian Polytechnical University, 44100 Gliwice, Poland
Carsten M. Nielsen Retrovirus Laboratory, Enterovirus Department, Statens Seruminstitut, Amager Boulevard 80,DK-2300 Copenhagen, Denmark Received February 22, 1990
Reaction of 1,5-di-O-acetyl-2,3-dideoxy-3-phthaIimido-~-D-e~fhro-pentoSynthese von 3’-(4-Nitroimidazol-l-yl)-2’,3’didesoxynukleosiden von Pyrimidin-Analogen und ihre biologische Priifung gegen HIV furanose (1) with silylated pyrimidinediones 2a-c using the Lewis acid trimethylsilyl triflate as catalyst afforded nucleosides 3a-c and 4a,c which were Die Reaktion von 1,5-Di-O-acetyl-2,3-didesoxy-3-phthalimido-P-D-e~fhrodeprotected with 33% methylmine,ethanol give the conesponding 3-aminonucleosides 5ac 6. were reacted with ,4dinitroimidazoles pentofuranose (1) mit den silylierten Pyrimidindionen 2a-c. katalysien durch
7a,b lo give the 3-imidamlyldideoxynucleosides 8a,b and 9a-f. At sub-toxic concentrations these compounds were ineffective aganist HN-I.
die Lewis-Saure Trimethylsilyltriflat, lieferte die Nukleoside 3a-c und 4a,c, deren Schutzgruppen mit 33 % Methylamin/Ethanol entfemt wurden. Dabei bildeten sich die entspr. 3-Aminonukleoside 5a-c und 6. Diese wurden mit den 1.4-Dinitroimidazolen 7a,b zu den 3-lmidazolyl-didesoxynukleosiden 8a,b und 9a-f umgesetzt. - Diese Verbindungen enviesen sich in subtoxischen Dosen als unwirksam gegen HIV- I.
Analogues of nucleosides that lack the 3’-OH group are being extensively studied as potential therapeutic agents for the treatment of AIDS. These compounds have been shown to be effective inhibitors of human immunodeficiency virus HIV1-6).3’-Deoxynucleosides are thought to be able to enter cells and are converted by cellular enzymes to their 5’-triphosphates which, upon incorporation into DNA by acting as competitive inhibitors or alternate substrates to HIV reverse transcriptase, produce chain termination’-’). In particular, 3’-azido-3’-deoxythymidinewas the first nucleoside analogue for which a selective inhibition of HIV was demonstrated in vitro*) and it is used clinically for the therapy of AIDS””). However, there is concern regarding the toxicity of AZT which has been recognized in clinical trials particularly on hematopoiesi~’~’’~’. As a result, several other nucleoside analogues have been reported that display HIV-inhibitory activity in ~ i f r o ~among ’ ~ ~ ) which , 3’-deoxy-3’-fluorothymidine has been found to be a more potent inhibitor of HIV than AZT but its toxicity deserves further investigation 15). There is, therefore, still a demand for compounds that are at least as active but less toxic than AZT.
3’-position. The nitroimidazole ring has a strong inductive electronegative character which, like fluorine atom, would affect the electronic properties of the substituted molecules and may produce a biologically active compound with an interesting activity against HIV.
As sugar-modified nucleosides are at present the most active class of compounds in HIV therapy, further efforts to change the structure of the sugar moiety seem to be warranted. On the other hand, the introduction of a strong electronegative atom like fluorine in organic compounds has frequently led to dramatic changes in their biological activity and enzymatic stability probably due to altering the electronic properties of the substituted molecule. These considerations led us to synthesize novel pyrimidine nucleoside derivatives having a nitroimidazole moiety at the
Arch. Pharm. (Weiriheini) 323.949-953 (1990)
Chemistry We have reported 16) the synthesis of 1,5-di-O-acetyl-2,3dideoxy-3-phthalimido-~-D-eryrhru-pentofuranose (1) which has been used for the synthesis of 3’-amino-3’-deoxythymidine (Sb) and its a-isomer 16) 6. Similarly, here we report the synthesis of 3’-amino-2’,3’-dideoxyuridine (5a) and 3’-amino-2’,3’-dideoxy-5-chlorouridine (Sc). Thus, uracil and 5-chlorouracil were silylated by the method of Wirrenburg ”) to give the corresponding silylated derivatives 2a and 2c. Using the reported procedure for nucleoside synthesis with trimethylsilyl triflate, the reaction of 1 with the silylated compounds 2a and 2c in acetonitrile could be easily completed to give an anomeric mixture of the corresponding 3’-phthalimido-2’,3’-dideoxynucleosidesin pla ratio = 312 from which the pure p-anomers 3a and 3c were obtained by crystallization from ethanol in 17% and 40% yields, respectively (Table 1, Scheme 1 ). The a-isomer 4c was obtained from the mother liquor of 3c in 11% yield. Actually, chromatographic separation of
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0365-6233/90/1212-0949 $3.50 + 2.510
950
Pedersen and coworkers
the anomeric mixtures to the corresponding a- and panomers proved to be extremely difficult since both anomers have exactly the same Rfvalue in all available eluents, probably due to the high lipophilicity of the phthalimido group. Treatment of 3a or 3c with 33% CH3NHfitOH at reflux temp. resulted in complete deprotection of both the hydroxy and the amino group to give the corresponding 3'-amino2',3'-dideoxynucleosides 5a and 5c in 70% and 84% yield, respectively. The 3'-amino-2',3'-dideoxynucleosides 5a-c and 6 were reacted with 1,4-dinitroimidazoles ") 7 in aqueous methanol at room temp. to give the corresponding 3'4troimidazolyl-2',3'-dideoxynucleosides 8a,b and 9a-f in 32-68% yields (Table 1, Scheme 2). The structures of the synthesized compounds were confirmed by their 'H-NMR, I3C-NMR data (Table 2 and 3) and elemental analysis (Table 1).
(CH,13Sio
*cod*c
ICH313SiOAN N+JR
phthN 1
+
2
TMS- triflote
0 H t 9 R
0"
N
phthN
4a R=CH, 4c RsCI
3
Biology
Scheme 1
8 a R'=W 8b R'zCH3
Compounds 8a,b and 9a-f were selected for in virro studies of biological effects. The compounds did not show any significant activity at sub-toxic concentrations against herpes simplex virus, type 1 (HSV-l), strain Mclntyre, when propagated in a continuous cell line from rabbit cornea (SIRL) which was maintained in Eagle's MEM containing 1% fetal calf serum and antibiotics. The same compounds were devoid of any activity against HIV-1 (strain HTLV-IIIB) in MT-4 cells, when MT-4 cells were incubated with virus, washed and added in a proportion of 1 : l O to uninfected MT-4 cells which had been preincubated in drug containing growth medium for 2 h. Expression of HIV in the culture medium was quantitated by HIV antigen detection ELISA. Only compound 9d showed cytotoxicity against MT-4 cells with TD50 = 70 pM. At sub-toxic concentrations this compound did not show any significant activity against HIV-I. The Danish Natural Science Research Council is gratefully acknowledged for supporting M.S. Motawia.
?(N. 0" N
Experimental Part 1,5-Di-O-acetyl-2,3-dideoxy-3-phthalimido-~-D-eryfhro-~ntofuranoseI6) (1). 3'-amin0-3'-deoxythyrnidine'~) (5b), and 1-(3-amino-2,3dideoxy-a-D-eryfhro-pentofuranosyl)-5-methyl-2.4-dioxo1,2,3,4tetrahydropyrimidine'6) (6) were prepared in our laboratory as reported. were pre1,4-Dinitr0imidazole'~)and 1,4-dinitr0-2-methylimidazole'~) pared as reported.
Scheme 2
CH3
CHa
CI
CH3
5'-0-Aceryl-2' 3'-dideoxy-3'-phthalimidouridine(3a), S'-O-acery~-2',3'-dideoxy-3'-phrhalimido-S-chlorouridine(3~), and I -(S-O-aceryl-23-dideoxy-3-phthalimidoaD-eryfhro-penfofuranosyl)S-chloro-2,4-dioxo1.2 3,4-fetrahydropyrimidine(4c) GeneralProcedure To a solution of 1 19) (6.95 g, 20 mmol) in 100 ml dry acetonitrile (refluxed over Pz05and subsequently over CaHz), the silylated uracil derivatives 17) (20 mmol) dissolved in 50 ml dry acetonitrile were added and the mixture was cooled to -3o'C. then a solution of trimethylsilyl
Arch.Pharm.(Weinheim)323,949-953(1990)
95 1
3’-(4-Nitroimidazol-I -yl)-2’,3’-dideoxynucleosides Table 1: Elemental analytical data of compounds 3a,c, 4c, 8a,b, and 9a-f.
Compound Yield
M-p.
No.
[%I
“Cl
3a
17
254-256
3c
4c
8a
8b
9a
9b
9c
9d
9e
9f
40
11
49
58
32
39
47
55
68
48
Formula
204-206
188-190 dec.
218-220 dec.
261-263 d e .
222-224 d e .
250-252
124-126
218-220 dec.
226-228 dec.
triflate (4 ml, 22 mmol) in 50 ml dry acetonitrile was added with magnetic stining over a 10 min period. The reaction mixture was stirred at -30’C for 2 h. Then the mixture was diluted with 250 ml methylene chloride and extracted with ice-cold saturated aq. NaHC03 solution. The org. phase was separated, washed with cold HzO (3 x 150 ml), dried over Na2S04. and evaporated under reduced pressure to give the crude products which, upon crystallization from EtOH, afforded the pure products 3a or 3c. Compound 4c was obtained from the mother liquour of 3c. Yields, m.p. and elemental analysis data: Table 1. - ‘H-NMFt and I3C-NMR: Tables 2 and 3.
H
Found
206-208
Arch. Pharni. (Weinheim)323.949-953 (1990)
Analysis
Calcd.
57.14
4.29
10.52
57.03
4.26
10.42
52.61
3.72
9.69
52.59
3.76
9.55
52.61
3.72
9.69
52.47
3.69
9.53
46.29
4.48
20.76
46.13
4.39
20.56
47.86
4.88
19.93
47.66
4.59
19.76
44.59
4.05
21.66
44.44
4.09
21.19
45.09
4.66
20.22
44.93
4.55
19.59
45.09
4.66
20.22
44.91
4.56
20.15
45.53
5.19
18.96
45.72
4.95
19.09
39.30
3.57
19.10
39.44
3.45
19.18
41.50
3.88
18.61
41.55
3.87
18.53
3’-Amino-2’3’-dideoxyuridine (5a) and 3’-Amino-2’3’-dideoxy-S. chlorouridine (5c) General Procedure
A 33% solution of methylamine in absol. EtOH (60 ml) was added to a stirred suspension of compound 3a or 3c (3.6 mmol) in 30 ml99.9% EtOH at room temp. After 5 min the clear solution obtained was refluxed for 2 h. The mixture was then cooled to room temp. and the solvent was evaporated under reduced pressure. The residue was chromatographed on silica
952
Pedersen and coworkers
Table 2: 'H-NhfR data of compounds 3a,c, 4c, 8a,b, and 9a-f (250 MHz, d6-DMSO. 6 in ppm).
11.40
11.39
11.39
11.39
11.36
11.37
11.92
11.86
s
8.77
8.87
8.69
8.72
8.70
8.74
8.69
8.72
s
8.05
NH
brs
5"-H 2"-H
11.40
11.94
11.95
8.03
8.03
8.03
6-H
7.83(d)
8.2Q(s)
8.22(s)
7.82(s)
7.91(s)
7.92(d)
7.95(d)
7.75(s)
7.77(9)
8.42(s)
8.4 l(s)
1'-H
6.47(t)
6.46(t)
6.30(t)
6.17(t)
6.22(t)
6.28c)
6.33c)
6.30cl
6.36(dd)
6.23(dd)
6.27(dd)
4.86
4.89
5.03
5.04
5.09
5.01
5.09
5.01
5.11
5.03
4.48
4.44
4.24
4.19
4.20
4.15
4.27
4.20
3.46
3.52
3.62
3.6Q
3.62
3.61
3.64
3.62
2.87
2.87
3'-H
m
4.84
4'-H
n~
4.44
4.45
5'4
in
4.22
4.26
2'a-H
m
2.76
2.79
4.18
2.76 2'PH
m
2.44
2.77
2.76 2.60
2.49
a)
1.85
s
phtli-A: 6 = 7.68
CH3CO:6 = 2.05 0.02 (s);
(ill),
f
2.77
2.72 2.44
2.45
1.88
b)
5-H: 6 = 5.71
2.78
2.73
2.67
2.45
2"-CH3 s
CH3
2.91
1.81
* 0.01 (d) and
C)
2.44
1.83
br s.
Table 3: 13C-NMR data of compounds 3a,c, 4c, 8a,b, and 9a-f (62.50 MHz, d6-DMS0, 6 in ppm). 3aa )
3c.)
4ca)
8a
8b
9a
9b
9c
9d
9e
9f
~
c-2 C-4
C-5 C-6 C-1' c-2' c-3'
C-4' C-5' c-2" C-4" C-5" CH3
a)
162.98 102.13 140.96
149.42 158.88 107.65 138.08
149.46 158.84 107.85 137.04
150.45 163.69 109.65 136.71
150.49 163.72 109.69 136.86
150.24 163.05 101.63 136.92
150.33 163.13 101.75 141.00
150.27 163.68 109.39 136.30
150.31 163.71 109.45 136.48
149.36 159.00 107.05 136.98
149.39 159.01 107.10 138.09
84.78 33.65 48.73 77.88 63.92
85.15 33.83 48.56 78.17 63.84
84.78 33.23 49.29 76.95 63.79
84.90 37.02 56.97 82.89 60.42
83.65 37.10 55.03 82.83 59.96
83.95 37.88
84.02 37.78 54.35 83.49 59.29
83.78 37.71 56.17 83.32 59.62
83.83 37.60 54.51 83.11 59.42
84.26 38.11 55.28 84.26 58.91
84.25 37.98 53.63 84.04 58.79
137.20 147.34 120.27 12.02
145.78 146.21 119.60 12.05 12.74
140.72 147.36 120.17
145.72 146.23 119.44 12.80
136.96 147.39 120.20 12.17
145.66 146.21 119.52 12.17 12.84
137.91 147.39 120.18
145.69 146.24 119.45 12.79
150.28
56.06
83.78 59.53
Shift values of CH3CO: 6 = 20.42, 167.50 and shift values of phthalimido group: 6 = 131.50 (C-3a), 123.00 (C-4), 134.40 (C-5), 167.50 (CO).
Arch. Pharm. (Webiheim) 323.949-953 (1990)
3’-(4-Nitroimidazol- 1-yl)-2’,3’-dideoxynucleosides gel (40 g. 0.04-0.063 mm) using CHCI3IMeOH (8:2) to obtain the pure products. Compound 5a: Yield 0.51 g (70%): M.p. 174-176’C (lit?”: 174-176’C). Compound 5c: Yield 0.7 g (84%): M.p. 110-112’C (lit?’): 108-112’C).
953 7 8
9 I -[3-(4-Nitroimidazol-I -yl)-23-dideoxya-D-erythro-peniofuranosyl]-5methyl-2,4-dioxo-l23.4-te~rahydropyrimidines 8a,b and I -[3-(4-Nitroimidazol- 1-ylJ-23-dideoxyQ-D-erylhro-pentofuranosyll2.4-dioxo- I 2 3.4-tetrahydropyrimidines 9a-f 10 General Procedure
To a vigorously stirred suspension of well powdered 1.4-dinitroimida-
ole'^' 7 (1.26 mmol) in 3.75 ml H20/MeOH (2:l) was added compound 5 or 6 (1.24 mmol) in portions at room temp. Stirring was continued for 2 h, then the resulting mixture was left overnight in an open flask. The precipitate formed was collected and recrystallization from aqueous ethanol yielded in most cases the pure products. Compounds 9b, 9d, and 9f were purified by chromatography on silica (20 g, 0.04-0.063 mm) using CHCIfleOH (9:l) as eluent. Yields, m.p., and elemental analysis data are reported in Table 1, ‘H-NMR and I3C-NMR data are reported in Tables 2 and 3.
11
12
13 14 15
References 1
2 3 4
5 6
E. DeClercq, J. Med. Chem. 29,1561 (1986). H. Mitsuya and S. Broder, Nature (London) 325,773 (1987). R. Dagani, Chem. & Eng. News 20.41 (1987). C.-H. Kim, V.E. Marquez, S. Broder, H. Mitsuya, and J.S. Driscoll, J. Med. Chem. 30,862 (1987). P. Herdewijn, J. Balzarini, E. DeClercq, R. Pauwels, M. Baba, S. Broder. and H. Vanderhaeghe, J. Med. Chem. 30,1270 (1987). R. Pauwels, M. Baba, J. Balzarini. P. Herdewijn, J. Desmyter, M.J. Robins, R. Zou, D. Madej, and E. DeClercq, Biochem. Pharmacol. 37, 1317 (1988).
Arch. Pharm. (Wcinheint) 323.949-953 (1990)
16 17 18
19 20 21
L. Vrang, H. Bazin, G. Remaud, J. Chartopadhyaya, and B. Oberg, Antiviral Res. 7. 139 (1987). H. Mitsuya, K.J. Weinhold, P.A. Furman, M.H.St. Clair, S. NusinoffLehrmann, R. C. Gallo, D. Bolognesi, D.W. Barry, and S. Broder, Proc. Natl. Acad. Sci. U.S.A. 82.7096 (1985). R. Yarchoan, R.W. Klecker, K.J. Weinhold, P.D. Markham, H.K. Lyerly, D.T. Durak, E. Gelmann, S. Nusinoff-Lehrman, R.M. Blum. D.W. Bany, G.M. Shearer, M.A. Fischl, H. Mitsuya, R.C. Gallo, J.M. Collins, D.P. Bolognesi, C.E. Myers, and S. Broder, Lancet 1986,575. R.E. Chaisson. J.-P. Allain, M. Leuther, and P.A. Volberding, N. Eng. J. Med.315, 1610(1986). M.A. Fischl, D.D. Richman, M.H. Grieco, M. S. Gottlieb, P.A. Volberding, O.L. Laskin, J.M. Leedom, J.E. Groopman, D. Mildvan, R.T. Schooley. G.G. Jackson, D.T. Durack, and D. King, N. Eng. J. Med. 317,185 (1987). D.D. Richman, M.A. Fischl, M.H. Grieco. M.S. Gottlieb. P.A. Volberding, 0.L. Laskin, J.M. Leedom, J.E. Groopman. D. Midvan. M.S. Hirsch, G.G. Jackson, D.T. Durak, and S. Nusinoff-Lehrman, N. Eng. J. Med.317, 192 (1987). J.-P. Sommadossi and R.Carlisle. Antimicrob. Agents Chemother. 3 / , 452 (1987). P. Herdewijn, R. Pauwels, M. Baba, J. Balzarini, and E. DeClercq, J. Med. Chem. 30.2 13I ( 1987). H. Hartmann, M.W. Vogt, A.G. Durno, M.S. Hirsch. G. Hunsmann. and F. Eckstein, AIDS Res. and Human Retmvir. 4,457 (1988). M.S. Motawia, J. Wengel, A.E.4. Abdel-Megied, and E.B. Pedersen, Synthesis 1989,384. E. Wittenburg,Z. Chem.4.303 (1964). H. Vorbriiggen, K. Krolikiewicz, and B. Bennua, Chem. Ber. 114, 1234(1981). J. Suwinski and E. Salwinska, Polish J. Chem. 61. 913 (1987): C.A. 109, 128905 (1988). M.S. Motawia, J.P. Jacobsen, and E.B. Pedersen, Chem. Scr. 29, 5 1 (1989): C.A. fI2,99088a(1990). T.A. Krenitsky, G.A. Freeman, S.R. Shaver, L.M. Beacham 111, S. Hurlbert, N.K. Cohn, L.P. Elwell, and J.W.T. Selway, J. Med. Chem. 26, 891 (1983) [Ph785]
3’-(4-Nitroimidazol- 1-yl)-2’,3’-dideoxynucleosides
Synthesis of 3’-(4-Nitroimidazol-l-yl)-2’,3’-dideoxynucleosidesof Pyrimidine Analogues and their Biological Evaluation against HIV Mohammed S. Motawia and Erik B. Pedersen* Department of Chemistry, Odense University, Campusvej 55,DK-5230 Odense, M, Denmark
Jerzy Suwinski Institute of Organic Chemistry and Technology, Silesian Polytechnical University, 44100 Gliwice, Poland
Carsten M. Nielsen Retrovirus Laboratory, Enterovirus Department, Statens Seruminstitut, Amager Boulevard 80,DK-2300 Copenhagen, Denmark Received February 22, 1990
Reaction of 1,5-di-O-acetyl-2,3-dideoxy-3-phthaIimido-~-D-e~fhro-pentoSynthese von 3’-(4-Nitroimidazol-l-yl)-2’,3’didesoxynukleosiden von Pyrimidin-Analogen und ihre biologische Priifung gegen HIV furanose (1) with silylated pyrimidinediones 2a-c using the Lewis acid trimethylsilyl triflate as catalyst afforded nucleosides 3a-c and 4a,c which were Die Reaktion von 1,5-Di-O-acetyl-2,3-didesoxy-3-phthalimido-P-D-e~fhrodeprotected with 33% methylmine,ethanol give the conesponding 3-aminonucleosides 5ac 6. were reacted with ,4dinitroimidazoles pentofuranose (1) mit den silylierten Pyrimidindionen 2a-c. katalysien durch
7a,b lo give the 3-imidamlyldideoxynucleosides 8a,b and 9a-f. At sub-toxic concentrations these compounds were ineffective aganist HN-I.
die Lewis-Saure Trimethylsilyltriflat, lieferte die Nukleoside 3a-c und 4a,c, deren Schutzgruppen mit 33 % Methylamin/Ethanol entfemt wurden. Dabei bildeten sich die entspr. 3-Aminonukleoside 5a-c und 6. Diese wurden mit den 1.4-Dinitroimidazolen 7a,b zu den 3-lmidazolyl-didesoxynukleosiden 8a,b und 9a-f umgesetzt. - Diese Verbindungen enviesen sich in subtoxischen Dosen als unwirksam gegen HIV- I.
Analogues of nucleosides that lack the 3’-OH group are being extensively studied as potential therapeutic agents for the treatment of AIDS. These compounds have been shown to be effective inhibitors of human immunodeficiency virus HIV1-6).3’-Deoxynucleosides are thought to be able to enter cells and are converted by cellular enzymes to their 5’-triphosphates which, upon incorporation into DNA by acting as competitive inhibitors or alternate substrates to HIV reverse transcriptase, produce chain termination’-’). In particular, 3’-azido-3’-deoxythymidinewas the first nucleoside analogue for which a selective inhibition of HIV was demonstrated in vitro*) and it is used clinically for the therapy of AIDS””). However, there is concern regarding the toxicity of AZT which has been recognized in clinical trials particularly on hematopoiesi~’~’’~’. As a result, several other nucleoside analogues have been reported that display HIV-inhibitory activity in ~ i f r o ~among ’ ~ ~ ) which , 3’-deoxy-3’-fluorothymidine has been found to be a more potent inhibitor of HIV than AZT but its toxicity deserves further investigation 15). There is, therefore, still a demand for compounds that are at least as active but less toxic than AZT.
3’-position. The nitroimidazole ring has a strong inductive electronegative character which, like fluorine atom, would affect the electronic properties of the substituted molecules and may produce a biologically active compound with an interesting activity against HIV.
As sugar-modified nucleosides are at present the most active class of compounds in HIV therapy, further efforts to change the structure of the sugar moiety seem to be warranted. On the other hand, the introduction of a strong electronegative atom like fluorine in organic compounds has frequently led to dramatic changes in their biological activity and enzymatic stability probably due to altering the electronic properties of the substituted molecule. These considerations led us to synthesize novel pyrimidine nucleoside derivatives having a nitroimidazole moiety at the
Arch. Pharm. (Weiriheini) 323.949-953 (1990)
Chemistry We have reported 16) the synthesis of 1,5-di-O-acetyl-2,3dideoxy-3-phthalimido-~-D-eryrhru-pentofuranose (1) which has been used for the synthesis of 3’-amino-3’-deoxythymidine (Sb) and its a-isomer 16) 6. Similarly, here we report the synthesis of 3’-amino-2’,3’-dideoxyuridine (5a) and 3’-amino-2’,3’-dideoxy-5-chlorouridine (Sc). Thus, uracil and 5-chlorouracil were silylated by the method of Wirrenburg ”) to give the corresponding silylated derivatives 2a and 2c. Using the reported procedure for nucleoside synthesis with trimethylsilyl triflate, the reaction of 1 with the silylated compounds 2a and 2c in acetonitrile could be easily completed to give an anomeric mixture of the corresponding 3’-phthalimido-2’,3’-dideoxynucleosidesin pla ratio = 312 from which the pure p-anomers 3a and 3c were obtained by crystallization from ethanol in 17% and 40% yields, respectively (Table 1, Scheme 1 ). The a-isomer 4c was obtained from the mother liquor of 3c in 11% yield. Actually, chromatographic separation of
OVCH Verlagsgesellschaft mbH, D-6940 Weinheim. 1990
0365-6233/90/1212-0949 $3.50 + 2.510
950
Pedersen and coworkers
the anomeric mixtures to the corresponding a- and panomers proved to be extremely difficult since both anomers have exactly the same Rfvalue in all available eluents, probably due to the high lipophilicity of the phthalimido group. Treatment of 3a or 3c with 33% CH3NHfitOH at reflux temp. resulted in complete deprotection of both the hydroxy and the amino group to give the corresponding 3'-amino2',3'-dideoxynucleosides 5a and 5c in 70% and 84% yield, respectively. The 3'-amino-2',3'-dideoxynucleosides 5a-c and 6 were reacted with 1,4-dinitroimidazoles ") 7 in aqueous methanol at room temp. to give the corresponding 3'4troimidazolyl-2',3'-dideoxynucleosides 8a,b and 9a-f in 32-68% yields (Table 1, Scheme 2). The structures of the synthesized compounds were confirmed by their 'H-NMR, I3C-NMR data (Table 2 and 3) and elemental analysis (Table 1).
(CH,13Sio
*cod*c
ICH313SiOAN N+JR
phthN 1
+
2
TMS- triflote
0 H t 9 R
0"
N
phthN
4a R=CH, 4c RsCI
3
Biology
Scheme 1
8 a R'=W 8b R'zCH3
Compounds 8a,b and 9a-f were selected for in virro studies of biological effects. The compounds did not show any significant activity at sub-toxic concentrations against herpes simplex virus, type 1 (HSV-l), strain Mclntyre, when propagated in a continuous cell line from rabbit cornea (SIRL) which was maintained in Eagle's MEM containing 1% fetal calf serum and antibiotics. The same compounds were devoid of any activity against HIV-1 (strain HTLV-IIIB) in MT-4 cells, when MT-4 cells were incubated with virus, washed and added in a proportion of 1 : l O to uninfected MT-4 cells which had been preincubated in drug containing growth medium for 2 h. Expression of HIV in the culture medium was quantitated by HIV antigen detection ELISA. Only compound 9d showed cytotoxicity against MT-4 cells with TD50 = 70 pM. At sub-toxic concentrations this compound did not show any significant activity against HIV-I. The Danish Natural Science Research Council is gratefully acknowledged for supporting M.S. Motawia.
?(N. 0" N
Experimental Part 1,5-Di-O-acetyl-2,3-dideoxy-3-phthalimido-~-D-eryfhro-~ntofuranoseI6) (1). 3'-amin0-3'-deoxythyrnidine'~) (5b), and 1-(3-amino-2,3dideoxy-a-D-eryfhro-pentofuranosyl)-5-methyl-2.4-dioxo1,2,3,4tetrahydropyrimidine'6) (6) were prepared in our laboratory as reported. were pre1,4-Dinitr0imidazole'~)and 1,4-dinitr0-2-methylimidazole'~) pared as reported.
Scheme 2
CH3
CHa
CI
CH3
5'-0-Aceryl-2' 3'-dideoxy-3'-phthalimidouridine(3a), S'-O-acery~-2',3'-dideoxy-3'-phrhalimido-S-chlorouridine(3~), and I -(S-O-aceryl-23-dideoxy-3-phthalimidoaD-eryfhro-penfofuranosyl)S-chloro-2,4-dioxo1.2 3,4-fetrahydropyrimidine(4c) GeneralProcedure To a solution of 1 19) (6.95 g, 20 mmol) in 100 ml dry acetonitrile (refluxed over Pz05and subsequently over CaHz), the silylated uracil derivatives 17) (20 mmol) dissolved in 50 ml dry acetonitrile were added and the mixture was cooled to -3o'C. then a solution of trimethylsilyl
Arch.Pharm.(Weinheim)323,949-953(1990)
95 1
3’-(4-Nitroimidazol-I -yl)-2’,3’-dideoxynucleosides Table 1: Elemental analytical data of compounds 3a,c, 4c, 8a,b, and 9a-f.
Compound Yield
M-p.
No.
[%I
“Cl
3a
17
254-256
3c
4c
8a
8b
9a
9b
9c
9d
9e
9f
40
11
49
58
32
39
47
55
68
48
Formula
204-206
188-190 dec.
218-220 dec.
261-263 d e .
222-224 d e .
250-252
124-126
218-220 dec.
226-228 dec.
triflate (4 ml, 22 mmol) in 50 ml dry acetonitrile was added with magnetic stining over a 10 min period. The reaction mixture was stirred at -30’C for 2 h. Then the mixture was diluted with 250 ml methylene chloride and extracted with ice-cold saturated aq. NaHC03 solution. The org. phase was separated, washed with cold HzO (3 x 150 ml), dried over Na2S04. and evaporated under reduced pressure to give the crude products which, upon crystallization from EtOH, afforded the pure products 3a or 3c. Compound 4c was obtained from the mother liquour of 3c. Yields, m.p. and elemental analysis data: Table 1. - ‘H-NMFt and I3C-NMR: Tables 2 and 3.
H
Found
206-208
Arch. Pharni. (Weinheim)323.949-953 (1990)
Analysis
Calcd.
57.14
4.29
10.52
57.03
4.26
10.42
52.61
3.72
9.69
52.59
3.76
9.55
52.61
3.72
9.69
52.47
3.69
9.53
46.29
4.48
20.76
46.13
4.39
20.56
47.86
4.88
19.93
47.66
4.59
19.76
44.59
4.05
21.66
44.44
4.09
21.19
45.09
4.66
20.22
44.93
4.55
19.59
45.09
4.66
20.22
44.91
4.56
20.15
45.53
5.19
18.96
45.72
4.95
19.09
39.30
3.57
19.10
39.44
3.45
19.18
41.50
3.88
18.61
41.55
3.87
18.53
3’-Amino-2’3’-dideoxyuridine (5a) and 3’-Amino-2’3’-dideoxy-S. chlorouridine (5c) General Procedure
A 33% solution of methylamine in absol. EtOH (60 ml) was added to a stirred suspension of compound 3a or 3c (3.6 mmol) in 30 ml99.9% EtOH at room temp. After 5 min the clear solution obtained was refluxed for 2 h. The mixture was then cooled to room temp. and the solvent was evaporated under reduced pressure. The residue was chromatographed on silica
952
Pedersen and coworkers
Table 2: 'H-NhfR data of compounds 3a,c, 4c, 8a,b, and 9a-f (250 MHz, d6-DMSO. 6 in ppm).
11.40
11.39
11.39
11.39
11.36
11.37
11.92
11.86
s
8.77
8.87
8.69
8.72
8.70
8.74
8.69
8.72
s
8.05
NH
brs
5"-H 2"-H
11.40
11.94
11.95
8.03
8.03
8.03
6-H
7.83(d)
8.2Q(s)
8.22(s)
7.82(s)
7.91(s)
7.92(d)
7.95(d)
7.75(s)
7.77(9)
8.42(s)
8.4 l(s)
1'-H
6.47(t)
6.46(t)
6.30(t)
6.17(t)
6.22(t)
6.28c)
6.33c)
6.30cl
6.36(dd)
6.23(dd)
6.27(dd)
4.86
4.89
5.03
5.04
5.09
5.01
5.09
5.01
5.11
5.03
4.48
4.44
4.24
4.19
4.20
4.15
4.27
4.20
3.46
3.52
3.62
3.6Q
3.62
3.61
3.64
3.62
2.87
2.87
3'-H
m
4.84
4'-H
n~
4.44
4.45
5'4
in
4.22
4.26
2'a-H
m
2.76
2.79
4.18
2.76 2'PH
m
2.44
2.77
2.76 2.60
2.49
a)
1.85
s
phtli-A: 6 = 7.68
CH3CO:6 = 2.05 0.02 (s);
(ill),
f
2.77
2.72 2.44
2.45
1.88
b)
5-H: 6 = 5.71
2.78
2.73
2.67
2.45
2"-CH3 s
CH3
2.91
1.81
* 0.01 (d) and
C)
2.44
1.83
br s.
Table 3: 13C-NMR data of compounds 3a,c, 4c, 8a,b, and 9a-f (62.50 MHz, d6-DMS0, 6 in ppm). 3aa )
3c.)
4ca)
8a
8b
9a
9b
9c
9d
9e
9f
~
c-2 C-4
C-5 C-6 C-1' c-2' c-3'
C-4' C-5' c-2" C-4" C-5" CH3
a)
162.98 102.13 140.96
149.42 158.88 107.65 138.08
149.46 158.84 107.85 137.04
150.45 163.69 109.65 136.71
150.49 163.72 109.69 136.86
150.24 163.05 101.63 136.92
150.33 163.13 101.75 141.00
150.27 163.68 109.39 136.30
150.31 163.71 109.45 136.48
149.36 159.00 107.05 136.98
149.39 159.01 107.10 138.09
84.78 33.65 48.73 77.88 63.92
85.15 33.83 48.56 78.17 63.84
84.78 33.23 49.29 76.95 63.79
84.90 37.02 56.97 82.89 60.42
83.65 37.10 55.03 82.83 59.96
83.95 37.88
84.02 37.78 54.35 83.49 59.29
83.78 37.71 56.17 83.32 59.62
83.83 37.60 54.51 83.11 59.42
84.26 38.11 55.28 84.26 58.91
84.25 37.98 53.63 84.04 58.79
137.20 147.34 120.27 12.02
145.78 146.21 119.60 12.05 12.74
140.72 147.36 120.17
145.72 146.23 119.44 12.80
136.96 147.39 120.20 12.17
145.66 146.21 119.52 12.17 12.84
137.91 147.39 120.18
145.69 146.24 119.45 12.79
150.28
56.06
83.78 59.53
Shift values of CH3CO: 6 = 20.42, 167.50 and shift values of phthalimido group: 6 = 131.50 (C-3a), 123.00 (C-4), 134.40 (C-5), 167.50 (CO).
Arch. Pharm. (Webiheim) 323.949-953 (1990)
3’-(4-Nitroimidazol- 1-yl)-2’,3’-dideoxynucleosides gel (40 g. 0.04-0.063 mm) using CHCI3IMeOH (8:2) to obtain the pure products. Compound 5a: Yield 0.51 g (70%): M.p. 174-176’C (lit?”: 174-176’C). Compound 5c: Yield 0.7 g (84%): M.p. 110-112’C (lit?’): 108-112’C).
953 7 8
9 I -[3-(4-Nitroimidazol-I -yl)-23-dideoxya-D-erythro-peniofuranosyl]-5methyl-2,4-dioxo-l23.4-te~rahydropyrimidines 8a,b and I -[3-(4-Nitroimidazol- 1-ylJ-23-dideoxyQ-D-erylhro-pentofuranosyll2.4-dioxo- I 2 3.4-tetrahydropyrimidines 9a-f 10 General Procedure
To a vigorously stirred suspension of well powdered 1.4-dinitroimida-
ole'^' 7 (1.26 mmol) in 3.75 ml H20/MeOH (2:l) was added compound 5 or 6 (1.24 mmol) in portions at room temp. Stirring was continued for 2 h, then the resulting mixture was left overnight in an open flask. The precipitate formed was collected and recrystallization from aqueous ethanol yielded in most cases the pure products. Compounds 9b, 9d, and 9f were purified by chromatography on silica (20 g, 0.04-0.063 mm) using CHCIfleOH (9:l) as eluent. Yields, m.p., and elemental analysis data are reported in Table 1, ‘H-NMR and I3C-NMR data are reported in Tables 2 and 3.
11
12
13 14 15
References 1
2 3 4
5 6
E. DeClercq, J. Med. Chem. 29,1561 (1986). H. Mitsuya and S. Broder, Nature (London) 325,773 (1987). R. Dagani, Chem. & Eng. News 20.41 (1987). C.-H. Kim, V.E. Marquez, S. Broder, H. Mitsuya, and J.S. Driscoll, J. Med. Chem. 30,862 (1987). P. Herdewijn, J. Balzarini, E. DeClercq, R. Pauwels, M. Baba, S. Broder. and H. Vanderhaeghe, J. Med. Chem. 30,1270 (1987). R. Pauwels, M. Baba, J. Balzarini. P. Herdewijn, J. Desmyter, M.J. Robins, R. Zou, D. Madej, and E. DeClercq, Biochem. Pharmacol. 37, 1317 (1988).
Arch. Pharm. (Wcinheint) 323.949-953 (1990)
16 17 18
19 20 21
L. Vrang, H. Bazin, G. Remaud, J. Chartopadhyaya, and B. Oberg, Antiviral Res. 7. 139 (1987). H. Mitsuya, K.J. Weinhold, P.A. Furman, M.H.St. Clair, S. NusinoffLehrmann, R. C. Gallo, D. Bolognesi, D.W. Barry, and S. Broder, Proc. Natl. Acad. Sci. U.S.A. 82.7096 (1985). R. Yarchoan, R.W. Klecker, K.J. Weinhold, P.D. Markham, H.K. Lyerly, D.T. Durak, E. Gelmann, S. Nusinoff-Lehrman, R.M. Blum. D.W. Bany, G.M. Shearer, M.A. Fischl, H. Mitsuya, R.C. Gallo, J.M. Collins, D.P. Bolognesi, C.E. Myers, and S. Broder, Lancet 1986,575. R.E. Chaisson. J.-P. Allain, M. Leuther, and P.A. Volberding, N. Eng. J. Med.315, 1610(1986). M.A. Fischl, D.D. Richman, M.H. Grieco, M. S. Gottlieb, P.A. Volberding, O.L. Laskin, J.M. Leedom, J.E. Groopman, D. Mildvan, R.T. Schooley. G.G. Jackson, D.T. Durack, and D. King, N. Eng. J. Med. 317,185 (1987). D.D. Richman, M.A. Fischl, M.H. Grieco. M.S. Gottlieb. P.A. Volberding, 0.L. Laskin, J.M. Leedom, J.E. Groopman. D. Midvan. M.S. Hirsch, G.G. Jackson, D.T. Durak, and S. Nusinoff-Lehrman, N. Eng. J. Med.317, 192 (1987). J.-P. Sommadossi and R.Carlisle. Antimicrob. Agents Chemother. 3 / , 452 (1987). P. Herdewijn, R. Pauwels, M. Baba, J. Balzarini, and E. DeClercq, J. Med. Chem. 30.2 13I ( 1987). H. Hartmann, M.W. Vogt, A.G. Durno, M.S. Hirsch. G. Hunsmann. and F. Eckstein, AIDS Res. and Human Retmvir. 4,457 (1988). M.S. Motawia, J. Wengel, A.E.4. Abdel-Megied, and E.B. Pedersen, Synthesis 1989,384. E. Wittenburg,Z. Chem.4.303 (1964). H. Vorbriiggen, K. Krolikiewicz, and B. Bennua, Chem. Ber. 114, 1234(1981). J. Suwinski and E. Salwinska, Polish J. Chem. 61. 913 (1987): C.A. 109, 128905 (1988). M.S. Motawia, J.P. Jacobsen, and E.B. Pedersen, Chem. Scr. 29, 5 1 (1989): C.A. fI2,99088a(1990). T.A. Krenitsky, G.A. Freeman, S.R. Shaver, L.M. Beacham 111, S. Hurlbert, N.K. Cohn, L.P. Elwell, and J.W.T. Selway, J. Med. Chem. 26, 891 (1983) [Ph785]
