Triphenylphosphine → (E)-6-chloro-9-[4-(diisopropoxyphosphoryl)but-3-enyl]purine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a mixture of 6-chloropurine (414 mg, 2.67 mmol), diisopropyl (E)-4-hydroxybut-1-enylphosphonate (630 mg, 2.67 mmol) and triphenyl phosphine (1.05 g, 4.00 mmol) in dry tetrahydrofuran (30 ml) stirred at 0° C. was added diethyl azodicarboxylate (0.70 g, 4.02 mmol). The mixture was allowed to warm to room temperature and stirred for 27.5 hr. The solvent was removed and the residue Was purified by column chromatography on silica gel eluting with dichloro-methane-methanol (24:1, 13:1) to give (E)-6-chloro-9-[4-(diisopropoxyphosphoryl)but-3-enyl]purine as a white solid (0.37 g, 37%), m.p. 105° C.; λmax (EtOH) 266 (9,260)nm; υmax (KBr) 3435, 2980, 1590, 1560, 1330, 1230 and 1210 cm-1 ; δH (CDCl3) 1.25 (12H, dd, J 6 Hz and 21 Hz, CH(CH3)2), 2.88 (2H, m, CH2), 4.45 (2H, t, J 7 Hz, CH2N), 4.55 (2H, m, CH(CH3)2), 5.68 (1H, dd, J 17 Hz and 20 Hz PCH=CH), 6.70 (1H, ddt, J 7 Hz, 17 Hz and 22 Hz, PCH=CH), 8.10 (1H, s, H-2/H-8), 8.77 (1H, s, H-2/H-8); FABMS (thioglycerol) 373 (MH+) (Found: C, 48.40; H, 6.03; N, 14.81%. C15H22ClN4O3P requires C, 48.33; H, 5.95; N, 15.03%).

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