Potassium Carbonate → (3-{(S)-5-[5-Chloro-3-fluoro-2-(5-methyl-[1,2,4]oxadiazol-3-yl)-phenyl]-indan-1-ylcarbamoyl}-oxetan-3-yl)-carbamic acid 9H-fluoren-9-ylmethyl ester

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Reaction Steps

To a solution of 3-(9H-fluoren-9-ylmethoxycarbonylamino)-oxetane-3-carboxylic acid (1.70 g, 5.01 mmol) in dry DMF (50.0 ml) were added N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (1.60 g, 8.35 mmol) and 1-hydroxybenzotriazole hydrate (0.95 g, 6.20 mmol) at room temperature. The resulting colorless solution was stirred for 10 min before a solution of (S)-5-[5-chloro-3-fluoro-2-(5-methyl-[1,2,4]oxadiazol-3-yl)-phenyl]-indan-1-ylamine (1.64 g, 4.77 mmol, intermediate A-11) in dry DMF (2.0 ml) was added. This mixture was stirred at room temperature for 20 h. Then water was added, the pH was adjusted to 9 with sat. K2CO3 solution and the mixture was extracted twice with MeCl2. The combined organic layers were washed with water and brine, dried with MgSO4 and evaporated. The remaining light brown foam was purified by chromatography (silica gel; MeCl2/MeOH 100:0 to 98:2%) and the title compound was obtained as off white foam (3.17 g, 100%). MS: 665.2 (MH+, 1Cl).

Provenance & Evidence