CAS 875309-82-3 appears in our catalog under these names: Carfilzomib Impurity 39, Benzyl (2S)-2-(((2S)-2-((((2S)-2-amino-4-phenylbutanoyl)amino)methyl)-4-methylpentanoyl)amino)-3-phenylpropanoate. Offered by: Chemat Brand, Biosynth. Available pack sizes: on request, 5000mg, 10000mg.