N-[(phenylmethoxy)carbonyl]-L-tryptophan 1,1-dimethylethyl ester → (S)-tert-Butyl 2-amino-3-(1H-indol-3-yl)propanoate

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Reaction Steps

To a solution of N-[(phenylmethoxy)carbonyl]-L-tryptophan 1,1-dimethylethyl ester (36 g; 98 mmol) in EtOH (150 mL) Pd/C 10% (5 g) was added. A H2 atmosphere was set and hydrogenation was performed with the aid of a Venturi type stirrer. Reaction conversion was estimated by HPLC (Chromatographic method L/46). After 6 h at r.t. the suspension was filtered through paper, then through Millipore® HA 0.45 μm and the filtrate was concentrated under reduced pressure to give a crude oil. The crude was dissolved in CHCl3 (200 mL) and washed with 5% aq. Na2CO3 (200 mL) and brine (150 mL). The organic layer was dried over Na2SO4 and concentrated to give L-tryptophan-1,1-dimethylethyl ester (18.16 g), which was used in the following step without further purification.

Provenance & Evidence