K. Barral et al. / European Journal of Medicinal Chemistry 45 (2010) 849–856
853
(370 mg, 1.65 mmol) in dry THF (16.5 mL) was slowly added over
45 min. After 2 h at ꢀ78 ꢁC, the reaction was quenched with satu-
rated aqueous NaHCO3 solution (1 mL) and solid NaHCO3 (329 mg).
The white suspension was allowed to warm to room temperature
overnight. The solvent was evaporated, the resulting slimy residue
resuspended in CH2Cl2 (60 mL), and the mixture filtered through
Celite. The white residue was twice removed from the top of the
Celite, washed with additional CH2Cl2 (40 mL), and refiltered. The
combined organic layers were concentrated to dryness and purified
by flash chromatography (CH2Cl2/MeOH 90:10) to afford compound
3 (662 mg, quant) as a colorless foam.
2 h then solvents were evaporated on vacuo to afford pure H-
phosphinate 6 (120 mg, quant) as a white solid; HPLC purity >98%.
1H NMR (D2O)
d
: 8.03 and 5.81 (dm, 2H, JPH ¼ 555.0 Hz), 7.45 (s,
1H), 6.05 (dd, 1H, J ¼ 2.9, 8.0 Hz), 5.26 (dd, 1H, J ¼ 3.2, 4.9 Hz), 4.17
(m, 1H), 3.17 (m, 1H), 3.12 (s, 3H), 2.80 (m, 1H), 2.41 (m, 1H), 2.10 (m,
1H), 2.03 (s, 3H), 1.79 (m, 2H). 13C NMR (D2O)
d: 165.73, 150.70,
136.27, 110.12, 83.90, 82.52, 79.40, 38.36, 36.98, 25.85
(d, JCP ¼ 93.3 Hz), 19.40 (d, J ¼ 2.0 Hz), 10.90. 31P NMR (D2O)
d:
34.79. HRMS (FAB) cald for C12H20N2O8PS (M þ H)þ 383.3392,
found 383.0678.
1H NMR (CDCl3)
d: 8.57 (s, 1H), 7.65 (s, 1H), 6.12 (dd, 1H, J ¼ 3.2,
4.1.6. 1-[(30R,40R)-30-Azido-20,30,50,60-tetradeoxy-60-
(hydroxyphosphinyl)-b-hexofuranosyl]thymine (7)
8.5 Hz), 4.31 (m,1H), 4.05 (m, 4H), 3.71 (m,1H), 2.55 (m,1H), 2.05 (m,
1H), 2.00 (m, 2H),1.83 (s, 3H),1.70 (m, 2H),1.27 (td, 6H, J ¼ 1.8, 7.0 Hz).
Sodium azide (256 mg, 3.94 mmol) was added to a solution of
the H-phosphinate 6 (188 mg, 0.49 mmol) in dry DMF (4 mL). The
reaction was stirred for 24 h at 60 ꢁC, then water (2 mL) was added
and the solvent was evaporated under vacum. The crude residue
was purified by HPLC with an X-Terra semi-preparative reversed-
phase column (linear gradient 0–100% B). Product fractions were
collected and evaporated to dryness. Excess triethylammonium
bicarbonate was removed by repeated freeze-drying with deionized
water to give 7 (83.2 mg, 51%) as a white powder. HPLC purity >97%
13C NMR (CDCl3)
d: 164.15, 150.77, 137.95, 110.47, 84.76, 84.55, 69.38,
62.15 (d, J ¼ 6.5 Hz), 40.85, 22.53 (d, JCP ¼ 142.2 Hz), 21.07 (d,
J ¼ 4.5 Hz),16.45(d, J ¼ 6.1 Hz),12.53. 31PNMR(CDCl3)
d:32.74. HRMS
(FAB) cald for C15H26N2O7P (M þ H)þ 377.3544, found 377.1478.
4.1.3. 1-[(30S,40R)-30-O-mesyl-20,50,60-trideoxy-60-
(diethoxyphosphonyl)-
To a stirred solution of compound 3 (438 mg, 1.17 mmol) in dry
pyridine (6 mL), methanesulfonyl chloride (108 L, 1.39 mmol) was
b-hexofuranosyl]thymine (4)
m
1H NMR (D2O)
d
: 8.07and 5.92 (dm, 2H, JPH ¼ 537.0 Hz), 7.50
slowly added at 0 ꢁC. The temperature was maintained at 0 ꢁC during
1 h. Then the reaction was allowed to warm to room temperature
overnight. The solvent was co-evaporated with toluene (10 mL). The
crude product was purified by flash chromatography (CH2Cl2/MeOH
93:7) to give 4 (405 mg, 77%) as a white foam.
(s, 1H), 6.23 (t, 1H, J ¼ 6.7 Hz), 4.31 (dd, 1H, J ¼ 5.6, 12.0 Hz), 4.08
(dd, 1H, J ¼ 5.6, 12.0 Hz), 2.56 (m, 2H), 1.98 (m, 2H), 1.93 (s, 3H), 1.72
(m, 2H). 13C NMR (D2O)
d: 167.50, 152.51, 137.17, 111.96, 84.73, 84.21,
83.94, 35.43, 26.80 (d, JCP ¼ 92.9 Hz), 25.49 (d, J ¼ 2.1 Hz), 11.74. 31
P
NMR (D2O)
d
: 29.49. HRMS (FAB) cald for C11H16N5O5P (M)ꢀ
1H NMR (CDCl3)
d
: 9.24 (s,1H), 7.26 (d,1H, J ¼ 1.2 Hz), 6.16 (dd,1H,
328.2447, found 328.0918.
J ¼ 3.2, 8.5 Hz), 5.12 (dd,1H, J ¼ 3.2, 5.0 Hz), 4.05 (m, 5H), 3.02 (s, 3H),
2.77 (m, 1H), 2.35 (dd, 1H, J ¼ 3.2, 16 Hz), 2.05 (m, 2H), 1.88 (d, 3H,
4.1.7. 1-[(30R,40R)-30-Azido-20,30,50,60-tetradeoxy-60-
J ¼ 1.2 Hz), 1.85 (m, 2H), 1.27 (t, 6H, J ¼ 7.0 Hz). 13C NMR (CDCl3)
d:
(boranophosphono)-
Compound 7 (50 mg, 0.14 mmol) was dried over P2O5 under
vacuum for 4–5 h then dissolved in dry THF (15 mL). BSA (195 L,
0.76 mmol) was added by syringe and the solution was stirred for
about 1 h at room temperature. DIPEA$BH3 (264 L, 1.5 mmol) was
b-hexofuranosyl]thymine (8)
163.83,150.52,135.06,111.25, 83.29, 82.15, 78.62, 61.94 (d, J ¼ 6.5 Hz),
39.92, 38.72, 25.21 (d, JCP ¼ 143.9 Hz), 24.31 (d, J ¼ 5.0 Hz), 16.51
m
(d, J ¼ 5.9 Hz), 12.69. 31P NMR (CDCl3)
d: 30.46. HRMS (FAB) cald for
C16H28N2O9PS (M þ H)þ 455.4461, found 455.1253.
m
added, and the solution stirred for 4 h, then a mixture H2O–MeOH
(1:1, 12 mL) was added. After the solvents were evaporated under
reduce pressure, the residue was purified by reversed-phase column
chromatography (linear gradient 0–100% B). Product fractions were
collected and evaporated to dryness. Excess of triethylammonium
bicarbonate was removed by repeated freeze-drying with deionized
water to give compound 8 (10 mg, 20%) as a white powder. HPLC
purity >98%.
4.1.4. 1-[(30S,40R)-30-O-mesyl-20,50,60-trideoxy-60-(phosphanyl)-
b-
hexofuranosyl]thymine (5)
Chlorotrimethylsilane (1.35 mL, 10.20 mmol) was added drop-
wise to a stirred solution of LiAlH4 (443 mg, 10.20 mmol) in dry THF
(8 mL) at ꢀ78 ꢁC. The resulting mixture was allowed to warm to
room temperature and stirred for 2 h. Compound 4 (800 mg,
1.70 mmol) in dry THF (8 mL) was added to the reducing mixture at
ꢀ70 ꢁC. The mixture was allowed to warm to room temperature
and stirred for 1 h. The reaction was stopped by slow addition of
H2O (2 mL) at ꢀ70 ꢁC. The mixture was allowed to warm to room
temperature and filtered through Celite. The organic layer was
dried over anhydrous MgSO4, filtered and concentrated under
reduced pressure. A purification by flash chromatography (CH2Cl2/
MeOH 95:5) yielded 5 (402 mg, 68%) as a white foam.
1H NMR (D2O)
d
: 7.32 (s, 1H), 6.04 (t, 1H, J ¼ 6.5 Hz), 4.08 (dd, 1H,
J ¼ 5.5, 11.2 Hz), 3.83 (dd, 1H, J ¼ 5.6, 11.0 Hz), 2.32 (t, 2H, J ¼ 6.5 Hz),
1.75 (m, 5H), 1.42 (m, 2H), 0.5 (bq, 3H, J ¼ 82 Hz). 31P NMR (D2O)
d:
103.54. HRMS (ESI) cald for C11H18N5O5PB (M)ꢀ 342.1139, found
342.1123.
1H NMR (CDCl3)
d
: 9.34 (s, 1H), 7.26 (d, 1H, J ¼ 1.2 Hz), 6.15 (dd,
4.1.8. 1-[(40R)-20,30-Didehydro-20,30,50,60-tetradeoxy-60-
(diethoxyphosphonyl)-b-hexofuranosyl]thymine (9)
1H, J ¼ 3.2, 8.5 Hz), 5.09 (dd, 1H, J ¼ 3.2, 5.0 Hz), 3.97 (m, 1H), 3.10
and 2.34 (dm, 2H, JPH ¼ 190.0 Hz), 2.99 (s, 3H), 2.77 (m,1H), 2.28 (m,
1H), 2.02 (m, 1H), 1.89 (d, 3H, J ¼ 1.2 Hz), 1.81 (m, 1H), 1.58 (m, 2H).
Potassium tert-butoxide (185 mg, 1.65 mmol) was added to
a solution of compound 4 (300 mg, 0.66 mmol) in dry DMF (4 mL).
The reaction was stirred at room temperature for 2.5 h, then the
solvent was evaporated on vacuo. The crude residue was purified by
flash chromatography (CH2Cl2/MeOH 95:5) to afford 9 (167 mg,
71%) as a white foam.
13C NMR (CDCl3)
d: 163.80,150.56,135.14,111.19, 83.37, 82.69, 79.09,
39.95, 38.80, 31.86 (d, J ¼ 3.4 Hz), 12.77, 10.36 (d, JCP ¼ 9.2 Hz). 31P
NMR (CDCl3)
d
: ꢀ136.52. HRMS (FAB) cald for C12H20N2O6PS
(M þ H)þ 351.3404, found 351.0780.
1H NMR (CDCl3)
d
: 9.00 (s, 1H), 6.90 (m, 2H), 6.28 (dt, 1H, J ¼ 1.5,
4.1.5. 1-[(30S,40R)-30-O-mesyl-20,50,60-trideoxy-60-
(hydroxyphosphinyl)-b-hexofuranosyl]thymine (6)
5.8 Hz), 5.76 (dt, 1H, J ¼ 5.8, 1.5 Hz), 4.77 (m, 1H), 4.03 (m, 4H), 2.02
(m, 2H), 1.84 (d 3H), 1.75 (m, 2H), 1.25 (td, 6H, J ¼ 1.5, 6.7 Hz). 13C
NMR (CDCl3) d: 163.65, 150.82, 136.38, 135.06, 125.53, 111.42, 89.77,
To a stirred solution of phosphine 5 (112 mg, 0.32 mmol) inwater
85.91, 61.81 (d, J ¼ 6.5 Hz), 28.87 (d, J ¼ 4.6 Hz), 23.14 (d,
(1 mL) and THF (1 mL) was added dropwise 35% aqueous hydrogen
peroxide (62 mL). The mixture was stirred at room temperature for
JCP ¼ 142.0 Hz),16.49 (d, J ¼ 6.0 Hz),12.53. 31P NMR (CDCl3)
d: 30.76.