# How do I convert 4-(Methylthio)benzaldehyde to 4-(thioacetate)benzaldehyde?

Sorry if I have the incorrect name of the final product. I'm trying to acylate the methyl mercaptan substituent to a thioester (thioacetate). I appreciate any help!

• The preferred prefix for the group $\ce{CH3-CO-S-{}}$ is “acetylsulfanyl”, which would lead to the product name “4-(acetylsulfanyl)benzaldehyde”. The former name “acetylthio”, which would lead to “4-(acetylthio)benzaldehyde”, may still be used in general nomenclature. However, the ester actually has seniority for citation as suffix, which leads to the preferred name “S-(4-formylphenyl) ethanethioate”. – Loong Feb 8 '16 at 14:16

You could react 4-(methylthio)benzaldehyde with $\ce{HBr}$ to form a thiol, and then react the thiol with acetyl chloride in triethylamine to form 4-(thioacetate)benzaldehyde.