9H-fluoren-9-ylmethyl-9-(phenylmethyl)-1-oxa-4,9-diazaspiro[5,5]undecane-4-carboxylate → 9H-fluoren-9-ylmethyl-1-oxa-4,9-diazaspiro[5.5]undecane-4-carboxylate

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Reaction Steps

To a solution of compound 403 (1.43 g, 3.05 mmol) in ethanol (27 mL) was added palladium hydroxide, 20 wt % pd (dry basis) on carbon, wet (1.51 g, 2.15 mmol), followed by hydrochloric acid (0.10 mL). The sealed glass tube was then evacuated and purged with hydrogen three times. The sealed tube was then charged with hydrogen (50 psi), and allowed to stir at room temperature for three days. HPLC showed ˜85% conversion to the desired product. After filtering the mixture through a plug of celite, the filtrate was concentrated to a solid and purified by flash chromatography (0-20% methanol in DCM with 1% NH4OH) to give compound 404 (709 mg, 61%) as a white solid. LCMS-ESI (POS), M/Z, M+1: Found 379.1, Calculated 379.2.

Provenance & Evidence