tert-Butyl 4-oxopiperidine-1-carboxylate → 4-((R)-7-methoxy-1,2,3,4-tetrahydro-naphthalen-2-ylamino)-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

To a solution of (R)-7-methoxy-1,2,3,4-tetrahydro-naphthalen-2-ylamine hydrochloride (6.0g, 28.1 mmol)(prepared as described in the French patent FR 2,653,765 or available commercially) and 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (6.7g, 33.7 mmol, 1.2 eq.) in dichloroethane (200 mL) under an inert atmosphere was added sodium triacetoxyborohydride (14.9 g, 70.2 mmol, 2.5 eq). The reaction was stirred at room temperature for 24 h then concentrated in vacuo. The residue was partitioned between EtOAc (200 mL) and 5% KOH (150 mL). The aqueous layer was extracted twice more with EtOAc (2×75 mL). The combined organic layers were dried (MgSO4), filtered, and concentrated to afford 4-((R)-7-methoxy-1,2,3,4-tetrahydro-naphthalen-2-ylamino)-piperidine-1-carboxylic acid tert-butyl ester as a yellow oil (9.7 g).

Provenance & Evidence