7964 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 22
Wu et al.
compound 4 was obtained as a white solid (52.5 mg, 90%). Mp
198-200 °C. 1H NMR (400 MHz, CD3OD) δ 8.55 (s, 1H), 8.22
δ154.7, 150.3, 143.7, 130.3, 118.4, 104.1, 87.1, 84.0 (Jc,p=8Hz),74.3,
70.6, 63.1 (Jc,p =4 Hz), 46.6, 16.7, 8.2; 31P NMR (162 MHz, D2O),
6.72 (s); HRMS (ESI-) m/z 328.0706 (M-, C12H15N3O6P requires
328.0689).
0
(d, 1H, J=5.0 Hz), 7.21 (d, 1H, J=5.0 Hz), 6.06 (d, 1H, J1 ,2
0
=
0
0
0
0
6.4 Hz), 4.82 (dd, 1H, J2 ,1 =6.4 Hz, J2 ,3 =5.2 Hz), 4.34 (dd, 1H,
0
0
0
0
0
0
0
0
J
3 ,2 =5.2 Hz, J3 ,4 =2.6 Hz), 4.19 (ddd, 1H, J4 ,3 =2.6 Hz, J4 ,5 =
4-Methyl-7-β-D-ribofuranosylpyrrolo[2,3-d]pyrimidine 50-Tri-
phosphate (7-Deaza-6-methyl-9-β-D-ribofuranosylpurine 50-Tri-
phosphate, 9). Prior to the reaction, tris(tetra-n-butylammonium)
hydrogen pyrophosphate (prepared as previously described,41
dried over P2O5, and stored at -20 °C, 116 mg, 0.13 mmol) and
compound 25 (55.0 mg, 0.130 mmol) were dried overnight under
vacuum at room temperature (22 °C) in two separate round-
bottom flasks. Anhydrous DMF (1.5 mL) and pyridine (250 μL,
3.00 mmol) were added to the round-bottom flask containing 22.
After the solid was dissolved, TMSCl (132 μL, 1.04 mmol) was
added by gastight microsyringe. After 5 min, a solution of I2 in
DMF (0.2 M, 910 μL) was added dropwise. The mixture was
stirred for 5 min at 22 °C before a solution of tris(tetra-n-
butylammonium) hydrogen pyrophosphate in DMF (0.5 mL) was
added. The reaction mixture was stirred at room temperature
(22 °C) for 30 min and concentrated in vacuo. The residue was
dissolved in cold deionized water (1 mL) by sonication for 1 min.
The precipitated iodine was removed by filtration through a small
plug of cotton inserted in the bottom of a 12 cm glass Pasteur pipet.
The product was purified by Sephadex LH-20 column with ice-
cold aqueous TEAB buffer (10 mM, pH 8) as the eluent. The
fractions containing the triphosphate were identified by mass spec-
trometry, combined, and lyophilized to yield the crude product,
which was further purified by preparative reverse-phase HPLC
with a linear gradient of 0-10% CH3CN in aqueous TEAB buffer
(10 mM, pH 7.5, adjusted with acetic acid) over 30 min (retention
time=10.8-12.0 min). Repeated lyophilization and resuspension
in deionized water (3 ꢀ 3 mL) yielded 9 as the triethylammonium
0
0
2.4, 2.6 Hz), 3.89 (dd, 1H, Jgem = 12.5 Hz, J5 a,4 = 2.4 Hz), 3.76
(dd, 1H, Jgem =12.5 Hz, J5 b,4 =2.6 Hz), 2.66 (s, 3H); 13C NMR
(100MHz, CD3OD) δ145.1, 143.5, 143.4, 140.4, 135.6, 119.7, 90.0,
73.7, 71.3, 62.1, 20.6, 14.9; IR (film) λmax 3271, 2912, 2852, 1610,
1501, 1206, 1081 cm-1;HRMS(ESIþ) m/z266.1138 (Mþ, C12H16-
N3O4 requires 266.1141).
0
0
4-Methyl-7-β-D-ribofuranosylpyrrolo[2,3-d]pyrimidine (7-Deaza-
6-methyl-9-β-D-ribofuranosylpurine, 6). After deprotection of
19, compound 6 was obtained as a white solid (52.7 mg, 90%).
Mp 175-176 °C. 1H NMR (400 MHz, CD3OD) δ 8.61 (s, 1H),
7.70 (d, 1H, J = 3.8 Hz), 6.74 (d, 1H, J = 3.8 Hz), 6.20 (d, 1H,
0 0 0 0 0 0
J1 ,2 =6.2 Hz), 4.61 (dd, 1H, J2 ,1 =6.2 Hz, J2 ,3 =5.5 Hz), 4.29
(dd,1H,J3 ,2 =5.5Hz,J3 ,4 =3.3 Hz), 4.10 (ddd, 1H, J4 ,3 =3.3Hz,
0
0
0
0
0
0
0
0
0
0
J4 ,5 =3.0, 3.3 Hz), 3.84 (dd, 1H, Jgem =12.2 Hz, J5 a,4 =3.0 Hz),
3.74 (dd, 1H, Jgem =12.2 Hz, J5 b,4 =3.3 Hz), 2.72 (s, 3H); 13C
NMR (100 MHz, DMSO-d6) δ 175.0, 159.4, 149.8, 127.3, 119.0,
100.0, 89.0, 85.6, 74.3, 71.0, 62.0, 20.7; IR (film) λmax 3293, 2923,
0
0
1594, 1569, 1514, 1432, 1361, 1232, 1125, 1084, 1042 cm-1
;
HRMS (ESIþ) m/z 266.1133 (Mþ, C12H16N3O4 requires
266.1141).
4-Methyl-7-(20,30-O-isopropylidene-β-D-ribofuranosyl)pyrrolo-
[2,3-d]pyrimidine (7-Deaza-6-methyl-9-(20,30-O-isopropylidene-
β-D-ribofuranosyl)purine, 20). Compound 6 (450 mg, 1.70 mmol)
was dissolved in acetone (5 mL). 1,2-Dimethoxypropane (5 mL)
and p-toluenesulfonic acid (442 mg, 4.20 mmol) were added. The
mixture was stirred at room temperature (22 °C) for 20 min.
MeOH (20 mL) was added to dilute the solution, and Amberlite
IRA-400 (OH) resin (from Supelco) was used to modify the pH
to 7. The resin was removed by filtration and washed with
MeOH (30 mL), and the filtrate was evaporated in vacuo. The
product was purified by flash chromatography (eluent: CH2Cl2/
MeOH, 25:1) to afford 404 mg of 20 as a white foam (78%). Mp
1
salt, a colorless glassy solid. H NMR (400 MHz, D2O) δ 8.56
(s, 1H), 7.76 (d, 1H, J=3.8 Hz), 6.82 (d, 1H, J=3.8 Hz), 6.30 (d,
0
1H, J1 ,2 = 7.0 Hz), 4.65 (dd, 1H, J2 ,1 =7.0 Hz, J2 ,3 =4.7 Hz),
0
0
0
0
0
0
0
0
0
4.48 (dd, 1H, J3 ,2 =4.7 Hz, J3 ,4 = 2.8 Hz), 4.27-4.26 (m, 1H),
4.18-4.04 (m, 2H), 3.08 (q, 18H, J = 7.3 Hz), 2.65 (s, 3H), 1.15
=
1
(t, 27H, J=7.3 Hz); 31P NMR (162 MHz, D2O) δ -10.2 (d, Jp,p
67-68 °C; H NMR (400 MHz, CD3OD) δ 8.64 (s, 1H), 7.69
0
0
=
3.6 Hz), 5.21 (dd, 1H, J2 ,1 = 3.6 Hz, J2 ,3 = 6.3 Hz), 5.03 (dd,
(d, 1H, J=3.8 Hz), 6.74 (d, 1H, J=3.8 Hz), 6.34 (d, 1H, J1 ,2
19.9 Hz), -11.3 (d, Jp,p = 19.9 Hz), -23.1 (t, Jp,p = 19.9 Hz);
HRMS (ESI-) m/z 503.9962 (M-, C12H17N3O13P3 requires
503.9974).
0
0
0
0
0
0
0
0
0
0
1H, J3 ,2 =6.3 Hz, J3 ,4 =2.9 Hz), 4.30 (dd, 1H, J4 ,3 =2.9 Hz,
4-Methyl-7-(20,30-O-isopropylidene-50-O-methyl-β-D-ribofu-
ranosyl)pyrrolo[2,3-d]pyrimidine (7-Deaza-6-methyl-9-(20,30-O-
isopropylidene-50-O-methyl-β-D-ribofuranosyl)purine, 21). 4-Methyl-
7-(20,30-O-isopropylidene-β-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidine
(20, 44.0 mg, 0.144 mmol) was dissolved in CH3CN (1 mL) and
cooled to 4 °C. NaH (11.6 mg, 0.288 mmol) was added, and the
resulting suspension was stirred at 4 °C for 0.5 h before adding MeI
(0.180 mL, 0.288 mmol). The mixture was stirred at room tempera-
ture (22 °C) for 2 h. MeOH (3 mL) was added to quench excess
NaH. After removal of solvent in vacuo, the crude product was
purified by flash chromatography (eluent: hexane/EtOAc, 1:1) to
0
0
0
0
J4 ,5 = 3.9 Hz), 3.78 (dd, 1H, Jgem = 12.0 Hz, J5 a,4 = 3.9 Hz),
0
0
3.72 (dd, 1H, Jgem=12.0 Hz, J5 b,4 =3.9 Hz), 2.72 (s, 3H), 1.63
(s, 3H), 1.39 (s, 3H); 13C NMR (100 MHz, CD3OD) δ 159.4,
150.1, 149.9, 127.3, 118.7, 114.0, 100.2, 90.6, 85.8, 84.0, 81.3,
62.0, 26.2, 24.2, 19.5; IR (film) λmax 3275, 2984, 2928, 1676,
1588, 1566, 1427, 1374, 1210, 1073 cm-1; HRMS (ESIþ) m/z
306.1443 (Mþ, C15H20N3O4 requires 306.1454).
4-Methyl-7-β-D-ribofuranosylpyrrolo[2,3-d]pyrimidine 50-H-
Phosphonate (7-Deaza-6-methyl-9-β-D-ribofuranosylpurine 50-H-
Phosphonate, 22).To a solution of phosphorus trichloride (0.500 mL,
5.73 mmol) in anhydrous CH2Cl2 at -20 °C, 4-methyl-7-(20,30-O-
isopropylidene-β-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidine (20, 174
mg, 0.570 mmol) was added, and the solution was stirred for 1 h at
-20 °C. The mixture was warmed to room temperature (22 °C) and
stirred for 4 h. The solvent was evaporated in vacuo, and the residue
was treated with aqueous TFA (2 mL, 30%) for 20 min. The reaction
mixture was concentrated in vacuo, the crude product was dissolved
in aqueous triethylammonium bicarbonate (TEAB) buffer (1 mL,
10 mM, pH 8), and the product was purified by Sephadex LH-20
column (2.5 cmꢀ40 cm). Elution with 10 mM aqueous TEAB buffer
and lyophilization yielded 22 as the triethylammonium salt, a color-
less glassy solid (139 mg, 62%). 1H NMR (400 MHz, D2O) δ 8.37
(s,1H),7.55(d,1H,J=3.8 Hz), 6.62 (d, 1H, J=3.8 Hz), 6.61 (d, 1H,
1
afford 40.0 mg of a colorless oil (86%). H NMR (400 MHz,
CDCl3) δ 8.78 (s, 1H), 7.38 (d, 1H, J =3.7 Hz), 6.58 (d, 1H, J =
0
0
0
0
3.7 Hz), 6.38 (d, 1H, J1 ,2 =2.9 Hz), 5.21 (dd, 1H, J2 ,1 =2.9 Hz,
0
0
0
0
0
0
J2 ,3 =6.4 Hz), 5.00 (dd, 1H, J3 ,2 =6.4 Hz, J3 ,4 =3.4 Hz), 4.39
0
0
0
0
(ddd, 1H, J4 ,3 =3.4 Hz, J4 ,5 =3.9, 4.8 Hz), 3.63 (dd, 1H, Jgem
=
0
0
0
0
10.3 Hz, J5 a,4 =3.9 Hz), 3.59 (dd, 1H, Jgem =10.3 Hz, J5 b,4 =4.8
Hz), 3.39 (s, 3H), 2.73 (s, 3H), 1.66 (s, 3H), 1.39 (s, 3H); 13C NMR
(100 MHz, CDCl3) δ 159.5, 151.5, 150.3, 125.9, 118.6, 114.4, 100.4,
90.4, 84.7, 84.5, 81.5, 72.9, 59.3, 27.3, 25.4, 21.5; IR (film) λmax 2984,
2928, 1586, 1512, 1460, 1374, 1347, 1215, 1092 cm-1;HRMS(ESIþ)
m/z 320.1595 (Mþ, C16H22N3O4 requires 320.1610).
4-Methyl-7-(50-O-methyl-β-D-ribofuranosyl)pyrrolo[2,3-d]-
pyrimidine (7-Deaza-6-methyl-9-(50-O-methyl-β-D-ribofuranosyl)-
purine, 7). Compound 21 (40.0 mg, 0.125 mmol) was treated with
aqueous TFA (70%, 1 mL) and stirred at room temperature
(22 °C) for 15 min. The solvent was removed in vacuo, and the
residue was purified by flash chromatography (eluent: CH2Cl2/
MeOH, 20:1) to yield 30.4 mg of 7 as a white foam (87%).
0
JP, H = 638 Hz), 6.19 (d, 1H, J1 ,2 = 6.4 Hz), 4.57 (dd, 1H, J2 ,1 =
6.4 Hz, J2 ,3 =5.6 Hz), 4.36 (dd, 1H, J3 ,2 =5.6 Hz, J3 ,4 =3.2 Hz),
0
4.22 (ddd, 1H, J4 ,3 = 3.2 Hz, J4 ,5 = 1.5, 1.2 Hz), 3.98 (dd, 1H,
0
0
0
0
0
0
0
0
0
0
0
0
0
gem=2.8 Hz, J5 a,4 =1.5 Hz), 3.97 (dd, 1H, Jgem=2.8 Hz, J5 b,4 =
0
0
0
J
1.2 Hz), 3.05 (q, 6H, J=7.4 Hz, N(CH2CH3)3), 2.46 (s, 3H), 1.13
(t, 9H, J = 7.4 Hz, N(CH2CH3)3); 13C NMR (100 MHz, D2O)