This image shows some kind of formula that could be converted to TeX. Storing formulas as images makes it harder to change them. TeX also helps making sure that they all use the same font and size.
A replacement has been proposed. In your article, replace the image with this code.
Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. TeX parse error: Invalid environment name '\text{matrix}'"): {\displaystyle {\begin{matrix}{}\\{\mathsf {{R{-}C{\equiv }C{-}H}\ +\ Br{-}C{\equiv }C{-}R'\quad {\xrightarrow[{\displaystyle NEt_{3}}]{\displaystyle \ CuBr\ }}\quad R{-}C{\equiv }C{-}C{\equiv }C{-}R'}}\end{matrix}}}