A. K. Reid et al. / Tetrahedron Letters 47 (2006) 4201–4203
4203
d6) d ppm: 10.83 (s, <1H, N–H), 8.31 (d, J = 7.48 Hz,
1H, 6 C–H), 7.18 (d, J = 7.44 z, 1H, 5 C–H), 6.10 (m,
1H, 10C–H), 5.24 (m, <1H, 30O–H), 5.01 (m, <1H,
50O–H), 4.21 (m, 1H, 30C–H), 3.84 (m, 1H, 40C–H),
3.57 (m, 2H, 50C–H), 2.30 (m, 1H, 20C–H), 2.09
(s, 3H, –CH3), 2.02 (m, 1H, 20C–H). 13C NMR
(100 MHz, DMSO-d6) d ppm: 171.92 (amide C@O),
163.20, 155.39, 145.91, 96.15, 88.84, 87.08, 61.9, 25.28
(acetyl –CH3), m/z (FAB): 270.11 (MH+). CHN (exp)
found: C (49.07) 48.46; H (5.62) 5.65; N: (15.61) 15.34.
O
O
Ph
O
Ph
No Reaction
H
N
DMF, reflux
N
N
Rapid Breakdown
NO2
Benzoyl chloride
DMF, reflux
Scheme 3. Attempted syntheses of a benzoyl analogue of 1.
Acknowledgement
one-d6) d ppm: 8.71 (dd, J = 8.3, 0.7 Hz, 1H), 8.43 (dd,
J = 7.8, 0.7 Hz, 1H), 8.02 (m, 1H), 3.05 (s, 3H, –CH3).
13C NMR (100 MHz, DMSO) d ppm: 170.0, 138.6,
138.2, 133.6, 131.1, 123.3, 121.5, 23.7, m/z (FAB):
207.1 (MH+), CHN (exp) found: C (46.61) 46.61; H
(2.93) 2.84: N (27.18) 27.08.
The authors would like to acknowledge Avecia for fund-
ing the supply of raw materials, and for their valuable
input.
References and notes
N-Acetyl-cytidine, 3: Into a flame-dried flask under N2
was weighed cytidine (0.1 g, 0.41 mmol, 1 equiv), and
this was dissolved in anhydrous DMF (5 ml). Com-
pound 1 (0.085 g, 0.41 mmol, 1 equiv) was added in
small portions over 5 min, and the resultant yellow solu-
tion was left to stir at room temperature overnight.
After this time, the solvent was removed in vacuo and
the yellow residue loaded onto silica and purified by
flash column chromatography, eluting with a gradient
system of 0–5% methanol in dichloromethane. The
product was obtained as a yellow solid, 0.09 g (89%).
mp 123–124 °C; 1H NMR (400 MHz, DMSO-d6) d
ppm: 10.85 (s, <1H, N–H), 8.40 (d, J = 7.2 Hz, 1H, 6
C–H), 7.17 (d, J = 7.4 Hz, 1H, 5 C–H), 5.78 (m, 1H,
10C–H), 5.43 (m, 1H, 20O–H), 5.13 (m, 1H, 50O–H),
5.02 (m, 1H, 30O–H), 3.95 (m, 2H, 50C–H), 3.90 (m,
1H, 40C–H), 3.72 (m, 1H, 20C–H), 3.59 (m, 1H, 30C–
H), 2.1 (s, 3H, –CH3), m/z (FAB): 286.104 (MH+).
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1
product. Mp 150–152 °C. H NMR (400 MHz, DMSO-