2,4-二硝基氟苯 、
(S)-1-[(R)-2-((S)-2-Amino-4-methyl-pentanoylamino)-propionyl]-pyrrolidine-2-carboxylic acid [(R)-2-methyl-1-(4-nitro-phenylcarbamoyl)-propyl]-amide 以71%的产率得到(S)-1-{(R)-2-[(S)-2-(2,4-Dinitro-phenylamino)-4-methyl-pentanoylamino]-propionyl}-pyrrolidine-2-carboxylic acid [(R)-2-methyl-1-(4-nitro-phenylcarbamoyl)-propyl]-amide