CAS 20263-07-4 appears in our catalog under these names: DL-2-AMINO-4-PHOSPHONOBUTYRIC ACID, DL-2-Amino-4-phosphonobutyric acid, 95% , DL-2-Amino-4-Phosphonobutyric Acid, ≥95%, ≥95%. Offered by: Sigma-Aldrich, Thermo Scientific (Alfa Aesar), Chemat. Available pack sizes: 100MG, 1G, 250MG, 500MG, 250mg .