To a solution of 5′-amino-2′,3′-isopropylidene adenosine in anhydrous DMF (conc. 0.2 M) was added Et3N (2.00 eq) and the corresponding nitrobenzenesufonyl chloride (1.50 eq) at 0 °C. The reaction mixture was stirred for 4 h at room temperature under argon then was diluted with AcOEt and brine. The aqueous layer was extracted with AcOEt and the combined organic extracts were washed with brine, dried over Na2SO4 and concentrated under vacuum. The precipitate was washed with Et2O and DCM to give the desired compound as a colored solid.