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

Participants

Reaction Conditions

Reaction Steps

A suspension of 6-chloro-9H-purine (25.36 g, 164 mmol) and 4-methylbenzenesulfonic acid (0.565 g, 3.28 mmol) in EtOAc (250 mL) was treated with 3,4-dihydro-2H-pyran (44.9 mL, 492 mmol). The mixture was heated at 90° C. and the solid slowly dissolved over 1 h. The flask was removed from the oil bath and the cloudy, yellow solution was filtered and concentrated in vacuo. The pale yellow residue was dissolved in DCM and purified by flash chromatography (50% EtOAc/hexane) (1 L silica/4 L solvent) to give 6-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purine (38.90 g, 99.3% yield) as a colorless oil which slowly crystallized. MS (ESI, pos. ion) m/z: 239.1 [M+H]+

Provenance & Evidence