4-Nitrophenol → HCID 22216129, compound

Participants

Reaction Steps

Ice-cold aqueous trifluoroacetic acid (10 ml) was added to a solution of Boc-L-Phe-NHCH2CN (5 mmol) in dichloromethane (10 ml). The reaction mixture was incubated at 20° C. for 30 minutes and then the solvent was removed by evaporation at 40° C. The residue was dissolved in chloroform, evaporated and the procedure repeated twice more. The resultant crude trifluoroacetate salt was dissolved in a solution of diisopropylethylamine (7.5 mmol) in dimethylformamide (10 ml) and Boc-Gly-p-nitrophenyl ester (6.25 mmol) and N-hydroxybenzotriazole monohydrate (6.25 mmol) were added. Sufficient diisopropylethylamine was then added dropwise to generate p-nitrophenol (golden colour) and the mixture was stirred at room temperature for 2 hours. N,N-diethylethylenediamine (1.5 ml) followed after 15 minutes by ethylacetate (60 ml) was added and the mixture was washed with water, aqueous triethylamine, water, aqueous potassium bisulphate, water, dried and evaporated. The residue was purified by chromatography on silica eluted with ethyl acetate:hexane (20:1) to yield Boc-Gly-L-Phe-NHCH2CN in the form of a foam.

Provenance & Evidence