Methylamine → (3S,4aS,8aS)-2-((2R,3S)-3-amino-2-hydroxy-4-phenylbutyl)-N-tert-butyldecahydroisoquinoline-3-carboxamide

Participants

Reaction Steps

(A)(ii) A suspension of 26.55 g of N-tert.butyl-2-[2(R)-hydroxy-4-phenyl-3(S)-phthalimidobutyl]-(4aS,8aS)-isoquinoline-3(S)-carboxamide (prepared as described in Example 1) in 100 ml of ethanol was treated with 25 ml of a 30% solution of methylamine in ethanol at room temperature for 1 hour. The mixture was evaporated to dryness under reduced pressure. The residue was dissolved in 250 ml of ethanol, treated with 250 ml of a saturated solution of hydrogen chloride in ethyl acetate and stirred at room temperature for 16 hours. The mixture was evaporated to dryness and the residue was partitioned between ethyl acetate and water. The aqueous phase was separated, made basic with solid sodium carbonate and then extracted with dichloromethane. The dichloromethane extract was washed with sodium chloride solution and evaporated to dryness. The residue was triturated with diethyl ether and, after filtration, there were obtained 17.48 g of 2-[3(S)-amino-2(R)-hydroxy-4-phenylbutyl]-N-tert.butyl-decahydro-(4aS,8aS)-isoquinoline-3(S)-carboxamide as a white solid; MS: m/e 402 [M+H]+.

Provenance & Evidence