反应详情

Trifluoroacetic acid (2 ml) was added to an ice cooled solution of (S)-2-[bis-(t-butoxycarbonyl)amino]-9-[3-benzyloxy-2-(diethoxyphosphorylmethoxy]propoxy]-6-methoxypurine (1.65 g, 2.3 mmol) in dry dichloromethane (30 ml) an the resulting solution left for 2 hours. After warming to ambient temperature, 10% Pd-C (800 mg) was added and the mixture hydrogenated at ambient temperature and pressure for 2 hours. The reaction mixture was filtered, the catalyst washed with dichloromethane (20 ml), the filtrate washed with saturated aqueous sodium bicarbonate solution, brine, dried (MgSO4) and evaporated to leave a colourless viscous oil. Chromatography of the oil on silica gel using dichloromethane/methanol 95:5 as the initial eluant, then changing the eluant to dichloromethane/methanol 90:10 gave (S)-2-amino-9-[2-(diethoxyphosphorylmethoxy)-3-hydroxypropoxy]-6-methoxypurine as a colourless oil (0.65 g, 67%). IR: νmax (film) 3360, 3230, 2990, 2940, 2910, 1620, 1585, 1500, 1485, 1455, 1390, 1335, 1265, 1240, 1165, 1120, 1060, 1025, 975, 825, 785 cm-1. 1H NMR: δH [(CD3)2SO] 1.23 (6H, t, J=7 Hz, (OCH2CH3)2), 3.45-3.60 (2H, m, collapses to d on D2O exchange, CH2OH), 3.70-3.85 (1H, m, CH), 3.96 (3H, s, OCH3), 3.9-4.15 (6H, m, (OCH2CH3, OCH2P), 4.31 (1H, dd, J=11.3 Hz, J=6.9 Hz, NOCHB), 4.45 (1H, dd, J =11.3 Hz, J=3 Hz, NOCHA), 4.84 (1H, t, J=5.5 Hz, D2O exchangeable OH), 6.59 (2H, br.s, D2O exchangeable NH2), 8.14 (3H, s, H-8). m/z: (FAB, thioglycerol matrix) 406 (MH+).

1. waitthe mixture hydrogenated at ambient temperature and pressure for 2 hours
2. filtrationThe reaction mixture was filtered
3. washthe catalyst washed with dichloromethane (20 ml)
4. washthe filtrate washed with saturated aqueous sodium bicarbonate solution, brine
5. dry with materialdried (MgSO4)
6. customevaporated
7. customto leave a colourless viscous oil