Ethyl orthoformate → tert-butyl 4-((1R,2R)-2-((3-fluoro-4-(1H-tetrazol-1-yl)benzyloxy)methyl)cyclopropyl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of tert-butyl 4-((1R,2R)-2-((4-amino-3-fluorobenzyloxy)methyl)cyclopropyl)piperidine-1-carboxylate (Step B product, 400 mg, 1.06 mmol), triethyl orthoformate (880 uL, 5.28 mmol), and sodium azide (344 mg, 5.28 mmol) in acetic acid (4.3 mL) that had been placed under an inert atmosphere was heat in a sealed vial at 100° C. for 3 hrs. The reaction mixture was cooled to rt and concentrated under reduced pressure. The resulting crude was partitioned between EtOAc (20 mL) and water (20 mL) and the layers were cut. The aqueous phase was extracted with EtOAc (20 mL×2) and the combined organic layers were dried over MgSO4, filtered, and concentrated under reduced pressure. The residue was loaded onto a silica column (KP-Sil 25 g SNAP column, Biotage system) eluting with a range of 20-60% EtOAc/Hex over 12 CV to give the desired compound (415 mg, 91%). LC/MS (m/z): 432 (M+H)+.

Provenance & Evidence