Propanal → ((r)-7-Methoxy-1,2,3,4-tetrahydro-naphthalen-2-yl)-piperidin-4-yl-propyl-amine

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Reaction Steps

To a solution of 4-((R)-7-methoxy-1,2,3,4-tetrahydro-naphthalen-2-ylamino)-piperidine-1-carboxylic acid tert-butyl ester (9.7g, 23.4 mmol) and propionaldehyde (2.0 mL, 28.1 mmol) in dichloroethane (150 mL) under a nitrogen atmosphere was added sodium triacetoxyborohydride (10.9 mg, 51.5 mmol) in a single portion. The reaction was stirred at room temperature for 24 h then concentrated in-vacuo. The residue was partitioned between EtOAc (175 mL) and 5% aq. KOH (150 mL). The aqueous phase was extracted twice more with EtOAc (2×30 mL). The combined organic layers were dried over MgSO4, filtered, and concentrated to afford 10.0 g of the protected amine, which was treated with trifluoroacetic acid as described herein to afford ((R)-7-methoxy-1,2,3,4-tetrahydro-naphthalen-2-yl)-piperidin-4-yl-propyl-amine (7.0 g).

Provenance & Evidence