2-METHYLPROPANOIC ANHYDRIDE 97-72-3 AI3-28521 EINECS 202-603-6 HSDB 5309 Isobutyric acid anhydride Isobutyric anhydride Isobutyric anhydride [UN2530] [Flammable liquid] Isobutyryl anhydride Propanoic acid, 2-methyl-, anhydride UN2530