Hydrochloric Acid → (3R*,5S*)-3-amino-5-{[4-chloro-3-(3-methoxy-propoxy)-benzyl]-cyclopropyl-carbamoyl}-piperidine-1-carboxylic acid 9H-fluoren-9-ylmethyl ester, hydrochloride

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Reaction Steps

A mixture of (3S*,5R*)-5-tert-butoxycarbonylamino-piperidine-1,3-dicarboxylic acid 1-(9H-fluoren-9-ylmethyl) ester (1.78 g, 3.82 mmol), HCTU (1.75 g, 4.23 mmol) and DIPEA (265.3 μl, 1.55 mmol) in a 1:1 mixture of CH2Cl2/CH3CN (20 ml) is stirred for 10 min at RT. After cooling to 5° C., [4-chloro-3-(3-methoxy-propoxy)-benzyl]-cyclopropyl-amine (1.04 g, 3.86 mmol) is added in one portion. The ice-bath is removed and the mixture stirred for 14 h at RT. The reaction mixture is diluted with ethyl acetate and washed twice with K2CO3 solution. The organic layer is dried (Na2SO4) and evaporated. The crude oil thus obtained is stirred with HCl (5M in 2-propanol, 12 ml, 60 mmol) for 1 h and then evaporated to afford the title compound as a yellow oil. tR (HPLC, Nucleosil C18; 5-100% CH3CN+0.1% TFA/H2O+0.1% TFA for 8 min, flow 1.5 ml/min): 6.31 min.

Provenance & Evidence