4-Nitrobenzoic Acid → HCID 118207285, compound

Participants

Reaction Steps

A mixture of diethylazodicarboxylate (12.9 mL, 81 mmol of 40% toluene solution), triphenyl phosphine (22 mL, 83 mmol), 4-nitrobenzoic acid (6.97 g, 42 mmol) and 200 mL tetrahydrofuran was stirred for 10 min under an Ar atmosphere. Then was added a solution of tert-butyl 4-(4-(benzyloxy)phenyl)-3-hydroxypiperidine-1-carboxylate (Example 56, step D, 8 g, 20.9 mmol) in tetrahydrofuran (100 mL) and the resulting mixture was stirred at rt overnight. It was then diluted with water and extracted twice with 50 mL ethyl acetate. The combined organic fractions were dried over Na2SO4, filtered, and evaporated to dryness. The residue was purified via silica gel chromatography (750 μm column, eluting with 0-50% ethyl acetate/hexane) to yield 6 gms (±)-rel-(3S,4R)-tert-butyl 4-(4-(benzyloxy)phenyl)-3-(4-nitrobenzoyloxyl)piperidine-1-carboxylate. LCMS (Method F) RT 2.68 min (87% AP), m/z 476.8 (MH+−t-butyl).

Provenance & Evidence