Diisopropylethylamine → Boc-D-phenylalanylproline (6-cyano-3-picolyl)amide

Participants

Reaction Steps

8.12 g of diisopropylethylamine and subsequently 11 ml (15 mmol) of propanephosphonic anhydride (50% strength solution in ethyl acetate) were added dropwise to a solution of 2.11 g (12.5 mmol) of 2-cyano-5-(aminomethyl)pyridine and 4.5 g (12.5 mmol) of Boc-D-Phe-Pro-OH in 70 ml of CH2Cl2 at −5° C. The mixture was then stirred for 2 h, during which the temperature was allowed to rise from −5° to 20° C. The organic phase was washed with water, 5% strength sodium bicarbonate and 5% strength citric acid solutions, dried over Na2SO4 and evaporated to dryness. A pale yellowish crystalline residue was obtained, melting point 167-170° C., and was used without further purification in the next reaction.

Provenance & Evidence