反应详情

A solution of 8-ethyl-6-(2,4,6-trimethylphenyl)purine (200 mg, 0.75 mmol) in anhydrous dimethylfomamide (5 mL) was cooled to 0° C., and treated with sodium hydride dispersion in mineral oil (72 mg 50% w/w, 1.50 mmol). After 1 hour, bromobutane (0.10 mL, 0.90 mmol) was added by syringe, and the mixture was allowed to stir for 12 hours. It was poured into ethyl acetate (120 mL), and was washed with water (3×120 mL) and brine (100 mL). The aqueous layers were back-extracted in sequence with ethyl acetate (120 mL), and the extracts were combined, dried over anhydrous sodium sulfate, filtered and evaporated. The residue was separated by column chromatography (silica gel, 20:80 ethyl acetate-hexane) to afford the title product as a viscous oil (64.2 mg, 0.20 mmol, 27%). TLC RF 0.20 (30:70 ethyl acetate-hexane). 1H NMR (300 MHz, CDCl3): d 8.96 (1H, s), 6.95 (2H, s), 4.25 (2H, t, J=7.5 Hz), 2.93 (2H, q, J=7.7 Hz), 2.32 (3H, s), 2.04 (6H, s), 1.91-1.86 (2H, m), 1.50-1.38 (2H, m), 1.39 (3H, t, J=7.7 Hz), 1.01 (3H, t, J=7.5 Hz). MS (NH3—CI): m/e 325 (3), 324 (23), 323 (100).

1. washwas washed with water (3×120 mL) and brine (100 mL)
2. extractionThe aqueous layers were back-extracted in sequence with ethyl acetate (120 mL)
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationfiltered
5. customevaporated
6. customThe residue was separated by column chromatography (silica gel, 20:80 ethyl acetate-hexane)