反应详情

50 g (0.4 mol) of 5-methylcytosine are added to a solution of the palladium(0) catalyst (1.6 mol %) prepared in situ as described above in 200 ml of dry tetrahydrofuran/200 ml of dry dimethylsulfoxide at 5° C. 49.2 g (0.6 mol) of epoxycyclopentene, dissolved in 100 ml of tetrahydrofuran, are added dropwise to this suspension, while stirring (1.5 hours). The mixture is stirred at room temperature for 3 days and then concentrated, and the residue is stirred with 2N sodium carbonate solution, filtered off and washed with water and acetone. 20.2 g (24.4% of theory) of 4-amino-5-methyl-1-[(1RS,4SR)-4-hydroxy-cyclopent-2-en-1-yl]pyrimidin-2(1H)-one of melting point 241°-245° C. are obtained. Chromatography (silica gel, methylene chloride/methanol 3/1) of the neutralized mother liquor gives, in addition to 5-methylcytosine (14.95 g, melting point 264°-269° C.) a further 9.87 g (11.9% of theory) of the title compound; total yield: 36.3% of theory. 1H NMR (270 MHz, d6 -DMSO); δ[ppm]: 7.23 (s, 1H), 7.12 (s, broad, 1H), 6.70 (s, broad, 1H), 6.09 (m, 1H), 5.74 (m, 1H), 5.45 (m, 1H), 5.17 (s, 1H), 4.61 (m, 1H), 2.71 (m, 1H), 1.81 (s, 3H), 1.27 (m, 1H).

1. customprepared in situ
2. additionare added dropwise to this suspension
3. stirringThe mixture is stirred at room temperature for 3 days
4. concentrationconcentrated
5. stirringthe residue is stirred with 2N sodium carbonate solution
6. filtrationfiltered off
7. washwashed with water and acetone