Triethylamine → N-(tert-Butoxycarbonyl)-4-nitro-L-phenylalanine

Participants

Reaction Conditions

Reaction Steps

p-Nitrophenylalanine (7.94 g, 37.8 mmol) was dissolved in 50% aqueous dioxane solution (60 ml) and triethylamine (0.9 ml, 56.7 mmol) added. BOC-ON (10.24 g, 41.6 mmol) (Aldrich Chemical Co.) was added and the solution stirred for two hours. Ethyl acetate (100 ml) and H2O (50 ml) were next added and the contents poured into a separatory funnel. The aqueous layer was retained and extracted twice with ethyl acetate (100 ml). The aqueous layer was cooled to 0° C. and the pH was adjusted to 2.0 with 3N HCl, whereupon a precipitate formed which was collected and dried under vacuum. The filtrate was extracted with ethyl acetate twice (100 ml), dried (MgSO4) and stripped to dryness. The two fractions provided to be identical and were combined (11.0 g, 94.0%). The melting point of the compound was 165° C.

Provenance & Evidence