Sodium Hydroxide → HCID 56974295, compound

Participants

Reaction Steps

14.9 g (27.5 mmoles) of the protected tripeptide ester obtained in Step 2 above are dissolved in 300 ml of methanol, 55 ml of a 1 n sodium hydroxide solution are added, and the mixture is allowed to stand at room temperature for 3 hours. Thereafter methanol is distilled off under reduced pressure, the aqueous solution is shaken thrice with 15 ml of ethyl acetate, each, and acidified to pH=3 with solid citric acid. The separated substance is filtered off, washed with water and dried in a vacuum desiccator. 8.1 g (65%) of tert.-butoxycarbonyl-L-tyrosyl-D-norleucyl-glycine are obtained; m.p.: 174°-175° C., Rf2 =0.35-0.45, [α]D20 =+2.0° (c=1%, in dimethyl formamide).

Provenance & Evidence