3,4-dihydro-2H-pyran → 5-iodo-N-methoxy-N-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole-3-carboxamide

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Reaction Steps

A mixture of 5-iodo-N-methoxy-N-methyl-1H-indazole-3-carboxamide (X) (16.5 g, 50 mmol), 3,4-dihydro-2H-pyran (10.3 mL, 113 mmol) and PPTS (0.12 g, 0.6 mmol) in DCM was heated to reflux for 5 hours. The solution was poured into a saturated NaHCO3 solution, the layers were separated, and the aqueous layer was extracted with DCM. The combined organic layers were washed with 5% aqueous citric acid and brine, dried over MgSO4, and concentrated. The crude product was purified on a silica gel column (100% EtOAc→3:97 MeOH:DCM) to provide 5-iodo-N-methoxy-N-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole-3-carboxamide (XI) as a white viscous oil (19.1 g, 46 mmol, 92% yield). 1H NMR (DMSO-d6) δ ppm 1.28-1.84 (m, 6H), 3.43 (s, 3H), 3.60-4.04 (s, 5H), 5.86-6.08 (m, 1H), 7.45-7.87 (m, 2H), 8.39 (s, 1H); ESIMS found for C15H18IN3O3 m/z 416 (M+H).

Provenance & Evidence