CAS 72975-44-1 appears in our catalog under these names: 2-Methyl-2,3-dihydro-4h-thieno[2,3-e][1,2]thiazin-4-one 1,1-dioxide, 95%, Lornoxicam Impurity 16, 2-Methyl-2H-thieno(2,3-e)(1,2)thiazin-4(3H)-one 1,1-dioxide, 97%. Offered by: Combi-blocks, Chemat Brand, AmBeed. Available pack sizes: 5g, 1g, on request.