State the empirical formula for benzene-1,3-dicarboxylic acid.
Benzene-1,3-dicarboxylic acid is an isomer of benzene-1,4-dicarboxylic acid. These two isomers can be distinguished using carbon-13 ($^{13}\text{C}$) NMR spectroscopy. State the number of peaks in the carbon-13 ($^{13}\text{C}$) NMR spectrum of each compound.
Name compound $P$.
Explain why the main product in this two-step synthesis is benzene-1,3-dicarboxylic acid rather than benzene-1,4-dicarboxylic acid.
Benzene-1,3-dicarboxylic acid can be made by the two-step synthesis shown below.
The reagents for step 1 are $\text{CH}_3\text{COCl}$ and $\text{AlCl}_3$. These reagents generate $\text{CH}_3\text{CO}^+$ ions, which then react with compound $P$. Name the mechanism of this reaction.
Draw the mechanism for the reaction of $\text{CH}_3\text{CO}^+$ ions with compound $P$. Include every relevant curly arrow and charge, the intermediate structure and the structure of compound $Q$.
Suggest a reagent and conditions to convert compound $Q$ into benzene-1,3-dicarboxylic acid in step 2.