Only bromobenzene and chlorobenzene can be prepared by Sandmeyer’s reaction. Fluoro-, iodo-, and astatobenzene cannot be synthesized using this method.
\( \text{M} \xrightarrow{\text{CH}_3\text{MgBr}} \text{N} + \text{CH}_4 \uparrow \xrightarrow{\text{H}^+} \text{CH}_3\text{COCH}_2\text{COCH}_3 \)