Benzylamine → (1S,2S,5R)-2-(Benzylamino-methyl)-3-aza-bicyclo[3.1.0]hexane-3-carboxylic Acid Tert-butyl Ester

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Reaction Steps

Benzylamine (2.95 mmol, 1.2 eq) is added to a solution of (1S,2S,5R)-2-Formyl-3-aza-bicyclo[3.1.0]hexane-3-carboxylic acid tert-butyl ester (2.46 mmol, 1.0 eq) in chloroform (6.0 mL). After 10 min the mixture is treated with sodium triacetoxyborohydride (2.95 mmol), stirred for additional 15 h and poured into a sat. aq. NaHCO3 solution. The layers are separated and the aq. layer is extracted once with chloroform. The combined organic layers are washed twice with sat. NaHCO3 solution and water. The solvents are removed in vacuo and the residue is dissolved in ether (30 mL). Aq. HCl (0.1 M, 40 mL) is added, the layers are separated and the organic layer is extracted twice with aq. HCl (0.1 M, 30 mL each). The combined aq. layers are washed with ether (20 mL), made alkaline by addition of NaOH solution (1.0 M, 20 mL) and extracted three times with ether (40 mL each). The combined organic layers are dried over MgSO4 and concentrated in vacuo to give a crude product which is used without further purification. LC-MS (basic): tR=0.96 min; [M+H]+=303.3.

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