Notes
J . Org. Chem., Vol. 64, No. 6, 1999 2151
ambient temperature for 30 min [TLC (S3) showed complete
conversion of 3 to 2b plus a small amount of 1-methyluracil (1b,
nm (ꢀ 5400, 9400), min 215, 260 nm (ꢀ 2200, 500), (pH 12) max
1
20
323 nm (ꢀ 15 000), min 268 nm (ꢀ 4200); H NMR δ 5.71 (d, J
<
2
10%)]. The solution was added cautiously to H O (10 mL), and
) 1.8 Hz, 1H), 9.70 (s, 1H), 12.05 (br s, 1H, ex); MS m/z 158.0195
-
+
+
this solution was applied to a Dowex 1 × 2 (AcO ) column. The
column was eluted with H
O, the eluate was concentrated (∼5
mL), EtOH (2 mL) was added, and the solution was cooled (∼0
(15, [BH
Anal. Calcd for C
C, 37.48; H, 3.85, N, 14.43.
2
]
) 158.0202), 133.0505 (24, [sugar] ) 133.0501).
2
9 11 3 8
H N O
: C, 37.38; H, 3.84; N, 14.53. Found:
°
C) overnight to give 2b (99 mg, 73%): mp 266-267 °C (lit.12
1-(â-D-Ar a bin ofu r a n osyl)-5-n itr ou r a cil (7b). Treatment of
6b (3.11 g, 7.5 mmol) in NaOMe/MeOH (0.2 M, 150 mL) by
procedure C (1 h) and crystallization (EtOH, three crops) gave
mp 264-265 °C); UV (pH 2) max 241, 310 nm (ꢀ 6600, 9700),
min 216, 263 nm (ꢀ 3700, 2300), (pH 12) max 325 nm (ꢀ 9200),
1
min 271 nm (ꢀ 3400); H NMR δ 3.41 (s, 3H), 9.32 (s, 1H), 12.02
a product (2.12 g, 97%) that was recrystallized (EtOH/MeOH or
+
4
(
br s, 1H, ex); MS m/z 171.0278 (100, M ) 171.0279). Anal.
H
2
O) to give 7b: mp 202-205 °C, ∼207 °C dec (lit. 197 °C dec);
Calcd for C
5
H
5
N
3
O
4
‚H
2
O: C, 31.75; H, 3.73; N, 22.22. Found:
UV (pH 2) max 239, 306 nm (ꢀ 7200, 9300), min 216, 262 nm (ꢀ
4400, 2400), (pH 12) max 324 nm (ꢀ 15 800), min 259 nm (ꢀ 4100);
C, 31.60; H, 3.79; N, 22.08.
1
4
+
Treatment of 1b with fuming nitric acid (d ) 1.51 g/mL, 4.5
equiv) at ambient temperature for 30 min gave 2b (85%) with
identical data.
( H NMR ); MS m/z 271.0436 (1, [M - H
2
O] ) 271.0441),
+
+
158.0163 (4, [BH
2
]
) 158.0202), 133.0499 (2, [sugar]
)
133.0501). Anal. Calcd for C
9
11 3 8
H N O : C, 37.38; H, 3.84; N,
2
′,3′,5′-Tr i-O-a cetyl-3-n itr ou r id in e (5). Treatment of 4a (3.7
g, 10 mmol) by procedure A [Cu(NO ‚3H O (6 g)/Ac O (45 mL),
h; organic phase (CHCl ) was washed additionally with 2%
EDTA/H O] gave a colorless oil that was dissolved (benzene) and
lyophillized to give 5 (4.14 g, quantitative): UV (MeOH) max
14.53. Found: C, 37.41; H, 3.81; N, 14.68.
3
)
2
2
2
2′-Deoxy-5-n itr ou r id in e (7c). Treatment of 4c (3.1 g, 10
mmol) by procedure B (18 h) gave an oil that was dissolved
(CHCl ) and chromatographed (silica gel, 1% MeOH/CHCl ). The
4
3
2
3
3
resulting oil was dissolved (EtOH) and evaporated several times
to give a glass that resolidified (after several days) to give 6c
(2.78 g, 78%): UV (MeOH) max 238, 302 nm (ꢀ 7200, 8700), min
216, 260 nm (ꢀ 4600, 2600); 1H NMR δ 2.08 (s, 6H), 2.56 (m,
2H), 4.28 (m, 2H), 4.38 (m, 1H), 5.23 (m, 1H), 6.10 (“t”, J ) 6.8
Hz, 1H), 8.98 (s, 1H), 12.21 (br s, 1H, ex); MS m/z 201.0760 (4,
1
2
55 nm (ꢀ 7200), sh 320 nm (ꢀ 1000), min 227 nm (ꢀ 3500); H
NMR δ 2.04, 2.06, 2.08 (3 × s, 3 × 3H), 4.32 (m, 3H), 5.36 (m,
1
H), 5.60 (dd, J ) 4.0, 6.0 Hz, 1H), 5.94 (d, J ) 4.0 Hz, 1H),
.17 (d, J ) 8.0 Hz, 1H), 7.95 (d, J ) 8.0 Hz, 1H); MS m/z
6
3
2
+
+
69.0926 (1, [M - NO
59.0818), 158.0187 (1, [BH
reported.
1
2
] ) 369.0934), 259.0816 (70, [sugar] )
+
+
+
2
]
) 158.0202); and other data as
[sugar] ) 201.0763), 158.0184 (1, [BH2] ) 158.0202).
1
0a
Treatment of 6c (2.78 g, 7.8 mmol) by procedure C (1 h) gave
a yellow powder (1.58 g, 74%, mp 140-143 °C) that was
recrystallized (EtOH) to give colorless fine needles of 7c: mp
154-155 °C (lit.12 149-150 °C); UV (pH 2) max 239, 305 nm (ꢀ
7800, 9800), min 215, 261 nm (ꢀ 4700, 2600), (pH 12) max 324
-(2,3,5-Tr i-O-a cet yl-â-D-a r a b in ofu r a n osyl)-5-n it r ou r a -
cil (6b). P r oced u r e B. Triflic acid (0.66 mL, 1.13 g, 7.5 mmol)
was added slowly to a solution of 4b (1.85 g, 5 mmol) and
-nitropyrazole (847 mg, 7.5 mmol) in dried MeCN (75 mL) at
1
1
ambient temperature. Stirring was continued for 72 h [TLC (S1)
nm (ꢀ 12 900), min 270 nm (ꢀ 4300); H NMR δ 2.28 (“t”, J ) 5.8
after 24 h showed ∼20% 4b], volatiles were evaporated, and the
Hz, 2H), 3.65 (m, 2H), 3.89 (“q”, J ) 4 Hz, 1H), 4.28 (m, 1H),
5.25 (t, J ) 5.5 Hz, 1H, ex), 5.31 (d, J ) 6.0 Hz, 1H, ex), 6.06
(“t”, J ) 5.8 Hz, 1H), 9.52 (s, 1H), 12.12 (br s, 1H, ex); MS m/z
3 2
residue was dissolved (CHCl ). The solution was washed (H O)
and dried (Na
2 4
SO ), and volatiles were evaporated. The residual
+
+
oil was crystallized (EtOH/i-PrOH, 10:1, two crops) to give 6b
1.98 g, 96%): mp 164-166 °C; UV (MeOH) max 235, 295 nm (ꢀ
158.0156 (5, [BH ] ) 158.0202), 117.0547 (34, [sugar]
)
2
(
7
2
9 11 3 7
117.0551). Anal. Calcd for C H N O : C, 39.57; H, 4.06; N,
1
800, 8800), min 217, 257 nm (ꢀ 6200, 3300); H NMR δ 2.00,
.10, 2.12 (3 × s, 3 × 3H), 4.37 (m, 3H), 5.23 (m, 1H), 5.44 (dd,
15.38. Found: C, 39.33; H, 4.16; N, 15.23.
2′,3′-O-Isop r op ylid en e-5′-O-n itr ou r id in e (8b). Treatment
of 8a (852 mg, 3 mmol) by procedure B (20 h) and recrystalli-
zation (EtOH, two crops) gave colorless needles of 8b (685 mg,
J ) 4.5, 3.0 Hz, 1H), 6.28 (d, J ) 4.5 Hz, 1H), 8.88 (s, 1H), 12.3
+
(
1
br s, 1H, ex); MS m/z 259.0815 (54, [sugar] ) 259.0818),
+
7b
58.0200 (4, [BH
C, 43.28, H, 4.13; N, 10.12. Found: C, 43.00; H, 4.14; N, 10.19.
-Nitr ou r id in e (7a ). Treatment of 4a (1.11 g, 3 mmol) by
2
]
) 158.0202). Anal. Calcd for C15
H
17
N
3
O
11
:
73%): mp (166-170 °C, transition) 182-183 °C (lit. 182-183
°C); UV (MeOH) max 258 nm (ꢀ 9800), min 230 nm (ꢀ 3000);
5
(
1
H NMR7b); MS m/z 329.0858 (3, [MH]
+
) 329.0860). Anal.
procedure B (28 h) gave a colorless oil that was dissolved (dried
benzene/∆), frozen (dry ice/acetone), and lyophillized to give 6a
Calcd for C12H15N O : C, 43.77; H, 4.59; N, 12.76. Found: C,
3
8
43.70; H, 4.66; N, 12.70.
(
7
6
1.21 g, 97%): mp ∼72-73 °C; UV (MeOH) max 235, 297 nm (ꢀ
3′,5′-Di-O-n itr oth ym id in e (9b). Treatment of 9a (1.21 g, 5
mmol) by procedure B [TfOH (3 equiv)/1-nitropyrazole (3 equiv),
48 h] gave a yellow oil that was chromatographed (silica gel,
1% MeOH/CHCl ) and recrystallized [hot EtOH/H O (1:1, 40
1
100, 8100), min 218, 258 nm (ꢀ 5500, 3300); H NMR δ 2.08 (s,
H), 2.10 (s, 3H), 4.34 (m, 3H), 5.40 (t, J ) 6.0 Hz, 1H), 5.58
(
1
1
dd, J ) 3.5, 6.0 Hz, 1H), 5.97 (d, J ) 3.5 Hz, 1H), 9.11 (s, 1H),
3
2
8b
+
2.3 (br s, 1H, ex); MS m/z 259.0820 (100, [sugar] ) 259.0818),
mL)] to give 9b (640 mg, 39%): mp 124-125 °C (lit. 131-132
+
2
] ) 158.0202).
58.0204 (6, [BH
P r oced u r e C. A sample of 6a (400 mg, 0.96 mmol) in NaOMe/
MeOH (0.2 M, 30 mL) was stirred at ambient temperature for
0 min (a white precipitate separated immediately). MeOH was
°C); UV (MeOH) max 258 nm (ꢀ 9800), min 230 nm (ꢀ 3000);
1
H NMR8b); MS m/z 332.0598 (7, M
[C10H12N O ] ) 332.0605).
+
(
4
9
Anal. Calcd for C10H12N O : C, 36.15; H, 3.64; N, 16.86. Found:
4
9
3
C, 36.01; H, 3.70; N, 17.18.
+
added, the resulting solution was neutralized [Dowex-50W (H )],
and the resin was filtered and washed (MeOH). Volatiles were
evaporated from the combined filtrates, and the residue was
recrystallized (EtOH, two crops) to give 7a (220 mg, 80%): mp
J O9822939
1
(20)
H NMR signals for H2′,3′,4′,5′,5′′ were overlapped multiplets,
1
1
1
88-190 °C (lit. mp 188-190 °C); UV (pH 2) max 236, 306
and peaks for the hydroxyl protons were broad, unresolved singlets.