Addition of 2-cyanoethyl diisopropyl chlorophosphoramidite to DMT protected 2'-desoxy-2'-fluoro-5-iodo-uridine. 11 (1.068 g), and dimethylaminopyridine (0.17 g, 1.39 mmol) was dissolved in 50.0 mL of dry DCM, diisopropylethylamine (1.03 mL, 7.95 mmol) and 2-cyanoethyl-diisopropylchlorophosphoramidite (1.01 mL, 4.25 mmol) were added. Under an atmosphere of nitrogen, the mixture was then stirred at room temperature for 2 hours. After the DCM was removed in vacuo to obtained thick yellow oil (14) (1.98 g). P NMR was run on the product, to prove the addition of the phosphoramidite group. No other analysis was run on it because of the air sensitive nature of the product. P NMR (DMSO-d 6 capillary in DCM): δ 149.00 (s, 1P).