Diisopropylethylamine → tert-butyl 6-(3,5-dimethylisoxazol-4-yl)-2-ethoxy-4-(5-fluoropicolinoyl)-1H-benzo[d]imidazole-1-carboxylate

Participants

Reaction Steps

To tert-butyl 6-(3,5-dimethylisoxazol-4-yl)-2-ethoxy-4-((5-fluoropyridin-2-yl)(hydroxy)methyl)-1H-benzo[d]imidazole-1-carboxylate (57 mg, 0.12 mmol) in dichloromethane (6 mL) was added Dess-Martin periodinane (154.1 mg, 0.34 mmol). After 15 minutes, the reaction was quenched with saturated Na2S2O3(aq) (10 mL) and extracted with dichloromethane (3×10 mL). The combined organics were washed with water (30 mL) and brine (30 mL), and dried over Na2SO4. To the crude solution was added N,N-diisopropylethylamine (0.05 mL, 0.26 mmol), 4-(dimethylamino)pyridine (6.8 mg, 0.05 mmol), and di-tert-butyl dicarbonate (120.9 mg). After 90 minutes, the reaction mixture was washed with water (2×30 mL), dried over Na2SO4, and concentrated in vacuo. Purification by flash chromatography (0-50% ethyl acetate/hexane) afforded tert-butyl 6-(3,5-dimethylisoxazol-4-yl)-2-ethoxy-4-(5-fluoropicolinoyl)-1H-benzo[d]imidazole-1-carboxylate as an amber residue.

Provenance & Evidence