The Synthesis of Poly-L-arginine

Abstract N ω-Tosyl-l-arginine-Na-carboxylic acid anhydride hydrochloride was obtained as a crystal by the reaction of Na-carbobenzyloxy-Nω-tosyl-l-arginine and thionyl chloride. After treatment with silver oxide to remove the hydrochloride, Nω-tosyl-l-arginine-Nω-carboxylic acid anhydride (NCA) was prepared; it was then polymerized to poly-Na-tosyl-l-arginine(M\fallingdotseq16200, n\fallingdotseq52), which was subsequently converted into poly-l-arginine hydrochloride by treating it with hydrogen fluoride and by passing it through a column of the hydrochloride form of the IRA-400 resin.