5-Deoxy-5-fluoro-N4-((n-pentyloxy)carbonyl)cytidine may be prepared
according to US Patent No. 6,114,520.
From 2',3'-bis-O-(tert-butyldimethylsilyl)-5'-deoxy-5-fluorocytidine and n-pentylchloroformate in dichloromethane and pyridine may be obtained 2',3'-
bis-O-(tert-butyldimethylsilyl)-5'-deoxy-5-fluoro-N4-((pentyloxy)carbonyl)
cytidine.From 2',3'-bis-O-(tert-butyldimethylsilyl)-5'-deoxy-5-fluoro-N4-
((pentyloxy)carbonyl)cytidineand tetrabutylammonium fluoride in
tetrahydrofuran at room temperature for 2 hours may be prepared the
product which by hydrolyses may be converted to 5-deoxy-5-fluoro-N4-
((pentyloxy)carbonyl)cytidine. Purification of the product may be carried out
by silica gel chromatography (using dichloromethane:methanol = 20:1 as an
eluent).
