Borane;pyridine → 4-[3-((-)-4-Hydroxy-6-aza-spiro[2.5]oct-6-yl)-propyl]-5-oxo-[1,4]diazepane-1-carboxylic acid tert-butyl ester

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Reaction Steps

5-Oxo-4-(3-oxo-propyl)-[1,4]diazepane-1-carboxylic acid tert-butyl ester (intermediate 61) (0.19 g, 0.7 mmol) was reacted with (−)-6-Aza-spiro[2.5]octan-4-ol hydrochloride (intermediate 83) (0.12 g, 0.7 mmol) in DCE:EtOH (1:1, 6 ml), AcOH (0.18 ml) and pyridine-borane complex (0.18 ml, 8M in pyridine, 1.4 mmol) for 20 minutes. The reaction was then concentrated, redissolved in CH2Cl2 and washed with sat. NaHCO3, dried (Na2SO4) and concentrated. The residue was purified by flash column chromatography (CH2Cl2:MeOH 8:2) to afford the title product (0.25 g, 91%) as a gum. MS: 382.4 (MH+).

Provenance & Evidence