Water → N-[(2,4,6-Trimethoxyphenyl)methyl]-L-asparagine

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Reaction Steps

The fully protected derivative Z-Asn(Tmob)-OBzl prepared in Step 1 (2.0 g, 3.75 mmol) was dissolved in acetic acid (50 ml), water (14 ml) and DMF (10 ml) by slight warming and vigorous stirring, nitrogen was flushed through the low pressure hydrogenation flask, 5% palladium on carbon catalyst (400 mg) was added, and a gentle stream of hydrogen continuously passed over the vigorously stirred solution for 2 hours. Nitrogen was once more flushed through the system and the catalyst removed by filtration through a doubled fluted Whatman No. 1 filter paper. The filtrate was evaporated, the residue dried in vacuo, and triturated under ethyl acetate to give a white solid. The suspension was cooled overnight to 4 degrees, then filtered and washed with ethyl acetate. Yield after drying 1.16 g (96%), Rf 0.55 single spot n-butanol/acetic acid/water (3:1:1).

Provenance & Evidence