The IUPAC name of CH3CH2COOCH 3 is methyl propanoate. This is because the compound has a methyl group (-CH3) attached to the third carbon of a propanoic acid (-COOH) molecule, which results in the name "methyl propanoate". The prefix "methyl" indicates the presence of a -CH3 group, and the suffix "-oate" indicates the presence of an ester functional group (-COO-).