Triphenylphosphine → (E)-9-[4-(diisopropoxyphosphoryl)but-3-enyloxy]-6-phthalimidopurine

Participants

Reaction Conditions

Reaction Steps

To a mixture of 9-hydroxy-6-phthalimidopurine (141 mg, 500 μmol), diisopropyl (E)-4-hydroxybut-1-enylphosphonate (110 g, 500 μmol) and triphenylphosphine (197 mg, 750 μmol) in tetrahydrofuran (5 ml) stirred at 0° C. was added diethyl azodicarboxylate (131 mg, 750 μmol). The mixture was then stirred at room temperature for 2 hr. The solvent was removed and the residue purified by column chromatography on silica gel eluting with dichloromethane-methanol (49:1, 16:1) to give (E)-9-[4-(diisopropoxyphosphoryl)but-3-enyloxy]-6-phthalimidopurine as a gum (200 mg, 80%); λmax (EtOH) 273 (14,380) nm; υmax (film) 2970, 1730 1590 1570 1355 1240 and 975 cm-1 ; δH [(CD3)2SO] 1.24 (12H, pseudo t, J 6 Hz, CH(CH3)2), 2.77 (2H, m, CH2), 4 60 (2H, m, CH(CH3)2), 4.66 (2H, t, J 6 Hz, CH2O ), 6.07 (1H, dd, J 17 Hz and 20 Hz, PCH=CH), 6.75 (1H, ddt, J 6 Hz, 17 Hz and 22 Hz, PCH=CH), 8.00-8.25 (4H, m, Ph), 9.00 (1H, s, H-2/H-8), 9.08 (1H, s, H-2/H-8) (Found: M+ 499. 1620. C23H26N5O6P requires M+ 499.1621).

Provenance & Evidence