3,4-dihydro-2H-pyran → 2,6-Dichloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purine

Participants

Reaction Conditions

Reaction Steps

2,6-Dichloro-9H-purine (20 g, 0.11 mol) and 4-toluenesulphonic acid monohydrate (0.2 g) were dissolved in ethyl acetate (300 ml), the mixture was heated to 50° C. and a solution of 2,3-dihydropyran (12.6 ml, 0.14 mol) in ethyl acetate (50 ml) was added slowly over 30 minutes. The reaction mixture was then cooled to room temperature, water (100 ml) was added and the pH of the solution was adjusted to 7 with a saturated aqueous solution of sodium hydrogen carbonate. The layers were separated and the organic layer was washed sequentially with water and brine, dried (anhydrous magnesium sulphate), filtered and evaporated under reduced pressure. The residue was twice azeotroped from pentane to afford the title compound as a slightly impure white solid (30.9 g).

Provenance & Evidence