CAS 1820603-32-4 appears in our catalog under these names: Methyl 5-BOC-6-methyl-4-oxo-6H,7H-pyrazolo[1,5-a]pyrazine-2-carboxylate, 95%, 5-tert-Butyl 2-methyl 6-methyl-4-oxo-6,7-dihydropyrazolo(1,5-a)pyrazine-2,5(4H)-dicarboxylate, 95%. Offered by: Combi-blocks, AmBeed. Available pack sizes: 1g, 250mg, 100mg.