Synthesis of Peptides Related to Gramicidin S. III.¹ The Decapeptide Containing L-Lysine Residues in Place of L-Ornithine²

Abstract

Decapeptide Containing l-Lysine Residues Instead of l-Ornithine 3051 5,7-Diammo-3-phenyl-v-triazolo(d)pyrimidine (XIV, R = CgHs).-Fifteen grams of the 4-anilino-2,5,6-triaminopyrimidine bisulfite (XII) was dissolved in 300 ml. of boiling water.To this solution was added 50 ml. of glacial acetic acid, and the solution was stirred while 10 g. of sodium nitrite in 100 ml. of water was slowly added. The solution was then heated on the steam-bath for 1 hr. and cooled. The resulting precipitate was filtered and washed with water.For analysis the compound was recrystallized from N,N-dimethylformamide to yield 4.5 g. of 5,7-diamino-3-phenyl-vtriazolo(d)pyrimidine (XIV, R = CgHg), m.p. >300°. This product was insoluble in aqueous potassium hydroxide solution.