Lithium Hydroxide → tert-Butyloxycarbonyl-glycylphenylalanine

Participants

Reaction Steps

(t-Boc-gly-phe-OCH3, 6a, (9.2 g, 2.7×10-2 mole), 1 M aqueous LiOH (30 ml, 3.0×10-2 mole), and methanol (100 ml) are stirred at room temperature for 2 hours. Most of the methanol is evaporated. The concentrate is diluted with water (10 ml) and transferred to a separatory funnel. The mixture is then acidified with 1 M aqueous HCl (50 ml) and the aqueous acidic mixture subsequently extracted with CHCl3 (4 times). The combined CHCl3 extracts are washed with saturated aqueous NaCl before being dried over Na2SO4. Filtration of the drying agent and evaporation of the filtrate gives a foam which when triturated with Et2O/hexane affords 7a as a colorless solid which crystallizes from ethyl acetate/hexane as colorless needles: 6.3 g (71%), m.p. 138°-141° C.

Provenance & Evidence