SOLFATO DELL'ALDEIDE DELLA D-FENILALANIL-L-PROLIL-L-ARGININA E PROCEDIMENTO PER LA SUA PREPARAZIONE

The invention relates to t-butyloxy-carbonyl-D-phenylalanyl-L-prolyl-L-arginine aldehyde hemisulfate and D-phenylalanyl-L-prolyl-L-arginine aldehyde sulfate, which is highly stable in aqueous solution, and to a process for preparing D-phenylalanyl-L-prolyl-L-arginine aldehyde sulfate from D-phenylalanyl-L-prolyl-L-arginine aldehyde hemisulfate or NG-carboxy derivative containing an acid-sensitive protecting group at its amino terminal, wherein the acid sensitive amino terminal protecting group or optionally the NG-carboxy group is removed with 1 to 12 N sulfuric acid, applied in 1 to 12 equivalent amounts and the resulting free tripeptide aldehyde sulfate isolated. The D-phenylalanyl-L-prolyl-L-arginine aldehyde sulfate of the invention possesses valuable anti-coagulant activity.