p-Toluenesulfonic acid → 4,6-dichloro-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazolo[3,4-d]pyrimidine

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Reaction Steps

pTsOH (30.2 mg, 0.159 mmol) was added to a solution of 4,6-dichloro-1H-pyrazolo[3,4-d]pyrimidine (300 mg, 1.587 mmol) and 3,4-dihydro-2H-pyran (200 mg, 2.381 mmol) in a mixture of tetrahydrofuran (ratio: 1.000, volume: 5 ml) and CH2Cl2 (ratio: 1.000, volume: 5 ml). The reaction mixture was stirred for 12 h at room temperature after which the solvent was removed in vacuo. The residue was taken in CH2Cl2 (20 mL) and poured into water (20 ml). The organic phase was separated, the aqueous phase was extracted with CH2Cl2 (20 mL), and the organic phases were combined. The combined organic phases were washed with water (40 mL), washed with brine (40 mL), dried over Na2SO4 and then concentrated. The resulting crude material was purified by flash chromatography (CH2Cl2/MeOH 99/1 increasing) to yield the title compound (397 mg, 1.454 mmol, 92% yield) as a pale white oil. 1H NMR (400 MHz, CDCl3): δ 8.19 (s, 1H), 5.99 (dd, 1H, J=2.4 & 10.4 Hz), 4.12 (m, 1H), 3.79 (m, 1H), 2.53 (m, 1H), 2.13 (m, 1H), 1.93 (m, 1H), 1.76 (m, 2H), 1.64 (m, 1H). ESI-MS: 273.0 [M+H]+.

Provenance & Evidence