Isopropanol → 2,6-dichloro-9-(propan-2-yl)-9H-purine

Participants

Reaction Steps

A 500 mL round bottom flask was charged with 2,6-dichloro-9H-purine (1.89 g, 10 mmol), isopropanol (3.1 mL, 40 mmol, 4 mol eq), THF (150 mL), and triphenylphosphine (polystyrene-bound, ˜3 mmol/g, 6.7 g, or about 20 mmol load) and the resulting mixture was stirred and cooled in a water bath under nitrogen. A solution of DBAD (4.85 g, 20 mmol) in THF (50 mL) was added dropwise via an addition funnel over 30 min and the resulting reaction mixture stirred at ambient temperature for 20 hr. The resin was removed by filtration and washed well with ethyl acetate. The combined filtrates were evaporated to give a light yellow solid that was purified via flash column chromatography (dry loaded using silica/DCM) with a gradient of 0-50% ethyl acetate in heptanes to give:

Provenance & Evidence