Vol. 21, No. 5, 2010
Meier et al.
865
Experimental
de Oliveira Tabalipa and Mr. Angelo Ruzza for the NMR
experiments. M.M.S. is grateful to CNPq for a research
fellowship. L.M. and G.C.M. thank CNPq and CAPES
for fellowships. Financial support by FAPESC-CNPq/
PRONEX-2003 and INCT-CAT are also gratefully
acknowledged.
General procedure for the solvolysis of acetylated
nucleosides
Microwave reactions were performed in 10 mL sealed
tubes in a commercially available monomode reactor
(CEM Discover) with IR temperature monitoring and a
non-invasive pressure transducer. In a typical procedure
(Condition A), acetylated nucleosides 1-12 (1.0 mmol),
MeOH (2.0 mL), water (2.0 mL) and Et3N (7.0 mmol)
were placed in a 10 mL glass tube. The vessel was then
sealed with a septum, placed into the microwave cavity and
irradiated with a maximum power of 50 W under stirring.
Substrate consumption was monitored by TLC (AcOEt/
MeOH 4:1) Total reaction times presented in Tables 1-3
refer to pulsed irradiations of 2-3 min with pre-set ramp
periods of 1 min. After allowing the mixture to cool to rt,
the vessel was opened and the contents were concentrated
under reduced pressure. The resulting residue was triturated
with MeOH and filtered to give a white solid in high purity.
All nucleoside derivatives were characterized by matching
their spectral data with those in the literature.
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o
o
White solid; mp 202-203 C (lit.: 208-210 C;14
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1601 (C=N), 1062 (C–O); 1H NMR (400 MHz, DMSO-d6):
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Acknowledgments
The authors wish to thank Central de Análises (UFSC)
for spectroscopic analysis. Special thanks to Ms. Eliane
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