Let's break down each synthesis step by step. --- ## **i) Synthesis from 4-methyl-1,3-dioxane-2,5-dione to 1-methyl-2,3-dihydro-1H-inden-1-one** **Starting material:** 4-methyl-1,3-dioxane-2,5-dione (methylsuccinic anhydride) **Product:** 1-methyl-2,3-dihydro-1H-inden-1-one **Steps:** 1. **Friedel–Crafts Acylation** - React methylsuccinic anhydride with benzene in the presence of AlCl₃. - This acylates benzene to give 4-methyl-3-oxo-3,4-dihydro-2H-inden-1-one. 2. **Cyclization (Intramolecular Friedel–Crafts)** - The acylated product will undergo cyclization under acidic conditions to give the indanone structure. **Summary of steps:** - Methylsuccinic anhydride + benzene, AlCl₃ → cyclize to 1-methyl-2,3-dihydro-1H-inden-1-one --- ## **ii) Synthesis from Benzene to 2-chloro-N-(4-methylphenyl)acetamide** **Starting material:** Benzene **Product:** 2-chloro-N-(4-methylphenyl)acetamide **Steps:** 1. **Nitration** - Nitrate benzene (HNO₃/H₂SO₄) to get nitrobenzene. 2. **Reduction** - Reduce nitrobenzene (Fe/HCl or catalytic hydrogenation) to aniline. 3. **Friedel–Crafts Alkylation** - Alkylate aniline with methyl chloride (CH₃Cl), but since direct alkylation is difficult due to the amine group, **acetanilide protection** may be needed: - Acetylate aniline (Ac₂O) → acetanilide - Alkylate with CH₃Cl/AlCl₃ → p-methylacetanilide - Hydrolyze to p-toluidine 4. **Acylation** - React p-toluidine with chloroacetyl chloride (ClCH₂COCl) to get 2-chloro-N-(4-methylphenyl)acetamide. **Summary of steps:** - Benzene → nitrobenzene → aniline → p-toluidine → 2-chloro-N-(4-methylphenyl)acetamide --- ## **iii) Synthesis from Benzene to 1-bromo-4-chlorobenzene** **Starting material:** Benzene **Product:** 1-bromo-4-chlorobenzene **Steps:** 1. **Chlorination** - Chlorinate benzene (Cl₂/FeCl₃) to get chlorobenzene. 2. **Bromination (Para-selective)** - Brominate chlorobenzene (Br₂/FeBr₃). The chlorine directs the incoming bromine to the para position. **Summary of steps:** - Benzene → chlorobenzene → 1-bromo-4-chlorobenzene --- ## **Final Answers (Stepwise Summary)** ### **i)** 1. Friedel–Crafts acylation of methylsuccinic anhydride with benzene (AlCl₃) 2. Cyclization to form the indanone ring system ### **ii)** 1. Nitration of benzene 2. Reduction to aniline 3. Acetylation to acetanilide 4. Friedel–Crafts methylation (para-selective) 5. Hydrolysis to p-toluidine 6. Acylation with chloroacetyl chloride ### **iii)** 1. Chlorination of benzene 2. Bromination of chlorobenzene (para-selective) --- Let me know if you need detailed mechanisms for any step!