Fmoc-N-hydroxysuccinimide → 3-oxa-7,9-diaza-bicyclo[3.3.1]nonane-7,9-dicarboxylic acid 7-tert-butyl ester 9-(9H-fluoren-9-ylmethyl) ester

Participants

Reaction Steps

A mixture of 3-oxa-7,9-diaza-bicyclo[3.3.1]nonane-7-carboxylic acid tert-butyl ester (716 mg, 3.14 mmol, WuXy AppTech) and 9-fluorenylmethoxycarbonyl-N-hydroxysuccinimide (1058 mg, 3.14 mmol) was prepared in anhydrous THF (11 mL) and stirred at RT for 2.5 hours. The reaction mixture was concentrated under vacuum to give a yellow oil. After purification by flash chromatography (silica, heptane/EtOAc), the title compound was obtained as a white foam (1.36 g, 93%). 1H NMR (300 MHz, CDCl3) δ 7.77 (d, J=7.5 Hz, 2H), 7.55 (d, J=7.3 Hz, 2H), 7.45-7.37 (m, 2H), 7.36-7.28 (m, 2H), 4.65-4.57 (m, 2H), 4.35-3.49 (m, 9H), 3.17-2.78 (m, 2H), 1.46 (s, 9H). HPLC (max plot) 96.5%; Rt 5.07 min. UPLC/MS: (MS+) 451.4 ([M+H]+).

Provenance & Evidence