CAS 872-50-4 appears in our catalog under these names: 1-Methyl-2-pyrrolidinone, 99+% , 1-Methyl-2-pyrrolidinone, HPLC Grade, 99.5% , 1-Methyl-2-pyrrolidinone, Spectrophotometric Grade, 99.5+% , 1-Methyl-2-pyrrolidinone, anhydrous, 99.5%, packaged under i, 1-Methyl-2-pyrrolidinone, ACS grade, 99.0+% . Offered by: Thermo Scientific (Alfa Aesar). Available pack sizes: 10000g, 2500g, 500g, 1L, 4L, *4x1L, *4x100ml, 100ml.