O-(N-methyl-N-(2-methyl-1-phenylpropan-2-yl)acetamide) Oxethazaine is an impurity of Oxethazaine (O846600), a potent local anesthetic that is active even in acidic conditions. It is used (usually in combination with an antacid) for the relief of pain associated with peptic ulcer disease or esophagitis. Molecular Formula: C41H58N4O4 Molecular Weight: 670.92