p-Toluenesulfonic acid → 1-[2,2-dimethyl-3-(tetrahydro-2H-pyran-2-yloxy)propyl]-4-iodo-1H-pyrazole

Participants

Reaction Steps

p-Toluenesulfonic acid (44 mg, 0.26 mmol) was added to a stirring solution of 3-(4-iodopyrazol-1-yl)-2,2-dimethyl-propan-1-ol (Compound 47E, 500 mg, 1.79 mmol) in DCM (2.58 mL). The mixture was stirred under argon, chilled in an ice-bath, then dihydropyran (0.261 mL, 2.86 mmol) was added, stirred and gradually warmed to rt over 16 hrs. The reaction mixture was diluted with EtOAc and washed with brine (2×), dried over sodium sulfate, filtered and concentrated in vacuo and purified using a Teledyne ISCO Combiflash® Rf system [0→10% EtOAc/Heptanes] to afford 597 mg of the title compound (92%). 1H NMR (400 MHz, CD3OD) δ 7.71 (s, 1H), 7.48 (s, 1H), 4.57 (t, J=3.5 Hz, 1H), 4.04-4.12 (m, 2H), 3.86 (d, J=3.0 Hz, 1H), 3.48-3.56 (m, 1H), 3.45 (d, J=9.3 Hz, 1H), 3.03 (d, J=9.6 Hz, 1H), 1.81-1.91 (m, 1H), 1.67-1.78 (m, 1H), 1.51-1.66 (m, 4H), 0.93 (d, J=4.8 Hz, 6H).

Provenance & Evidence