反应详情

A solution of 6-chloroadenosine (2.58 g) and cyclohexylamine (5 g) in ethanol (20 ml) was heated at reflux for 6 hours then cooled to room temperature. The reaction mixture was concentrated in vacuo and the resultant residue was diluted with water (50 ml) and ethyl acetate (300 ml). The organic layer was separated and the aqueous layer was extracted with ethyl acetate (2×50 ml). The combined organic layers were washed with water (1×30 ml), dried over sodium sulfate, concentrated in vacuo and dried under vacuum to provide N6-cyclohexyladenosine as a white solid (2.600 g). N6-Cyclohexyladenosine (2.6 g) was diluted with acetone (30 ml) and to the resultant solution was added 2,2-dimethoxypropane (12 ml), followed by D-camphorsulphonic acid (3.01 g) and the mixture was allowed to stir at room temperature for 18 hours. The reaction mixture was concentrated in vacuo and the resultant residue was diluted with ethyl acetate (150 ml), then neutralized to pH 8.0 using saturated aqueous NaHCO3. The organic layer was separated, dried over sodium sulfate, concentrated in vacuo. The residue was purified twice on the silica gel column using MeOH—CH2Cl2 (4:96) as an eluent to provide 2′,3′-isopropylidene-N6-cyclohexyladenosine (3.16 g). 1H NMR (CDCl3): δ 1.23-1.47 (m, 9H), 1.38 (s, 3H), 1.64 (s, 3H), 1.79-1.81 (m, 1H), 2.04-2.06 (m, 1H), 3.80 (d, J=12 Hz, 1H), 3.96 (d, J=12 Hz, 1H), 4.53 (s, 1H), 5.09-5.16 (m, 2H), 5.80-5.92 (m, 2H), 7.79 (s, 1H), 8.24 (s, 1H), 8.22-8.38 (m, 1H).

1. temperatureat reflux for 6 hours
2. concentrationThe reaction mixture was concentrated in vacuo
3. additionthe resultant residue was diluted with water (50 ml) and ethyl acetate (300 ml)
4. customThe organic layer was separated
5. extractionthe aqueous layer was extracted with ethyl acetate (2×50 ml)
6. washThe combined organic layers were washed with water (1×30 ml)
7. dry with materialdried over sodium sulfate
8. concentrationconcentrated in vacuo
9. customdried under vacuum