Methyl oxalate, or methyl oxalic acid, is an ester formed from oxalic acid and methanol. To produce methyl oxalate, you would typically perform an esterification reaction between oxalic acid (H₂C₂O₄) and methanol (CH₃OH) in the presence of an acid catalyst, such as sulfuric acid, to drive the reaction.
Using hydrochloric acid (HCl) in the reaction instead of sulfuric acid might not be effective, as HCl is not a strong dehydrating agent