Acetic formic anhydride, or ethanoic methanoic anhydride is a chemical compound with formula , or -(C=O)-O-(C=O)H. It can be viewed as the mixed anhydride of acetic acid (H₃C-(C=O)OH) and formic acid (H(C=O)OH) by removal of a molecule of water.

It can be produced by reaction between sodium formate and acetyl chloride in anhydrous diethyl ether, at 23 27 C.^[1] Among other uses, it is a formylation agent for amines, amino acids, and alcohols, and a starting material for formyl fluoride.^[1]

See also

• Formic anhydride
• Acetic anhydride
• Acetic oxalic anhydride

References