3,4-dihydro-2H-pyran → 2,5-Dichloro-N-(5-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-3-yl)pyrimidin-4-amine

Participants

Reaction Steps

To a mixture of 2,5-dichloro-N-(5-methyl-1H-pyrazol-3-yl)pyrimidin-4-amine (2.44 g, 10 mmol) and 4-toluenesulfonic acid monohydrate (1.9 g, 10 mmol) in THF (200 mL), was added DHP (4.25 g, 50 mmol). After stirring overnight, the reaction turned clear. After concentration, the residue was dissolved in ethyl acetate and washed with Na2CO3 saturated aqueous solution. The organic layer was then washed with brine, dried over sodium sulfate and concentrated in vacuo to afford 2,5-Dichloro-N-(5-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-3-yl)pyrimidin-4-amine as light yellow solid, which was used in subsequent reactions without further purification; ESMS m/z 244 (M−THP+H+); TLC Rf=0.6 (Silica; 1:1 ethyl acetate/hexanes; starting material Rf=0.2).

Provenance & Evidence