Methanol → (9H-fluoren-9-yl)methyl piperidine-1-carboxylate

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Reaction Steps

A solution of 7.4 g Fmoc-βPhPro-OH in 120 ml dry DCM was added to 12.0 g 2-chlorotrityl chloride resin (0.83 mmol/g, Novabiochem). DIPEA (3.0 ml) was added and the mixture was shaken for 10 min. Additional 4.5 ml DIPEA were added and shaking was continued for 145 min. Methanol (10 ml) was added the mixture was shaken for another 25 min. The resin was filtered off, washed with DCM (5×100 ml), methanol (2×100 ml) and DCM (4×100 ml). A small sample was dried carefully and deprotected with DCM/piperidine (1:1) for 30 min. Photometric determination of the resulting Fmoc-piperidine adduct (absorption at 301 nm) gave a resin loading of 0.54 mmol/g. The remaining resin was treated with 100 ml DCM and 80 ml piperidine at r.t. for 160 min, washed with DCM (10×100 ml) and diethyl ether (4×80 ml) and dried in vacuo to give 14.37 g HβPhPro-2-chlorotrityl resin.

Provenance & Evidence