Q6(b). Quaternisation, then Sommelet–Hauser rearrangement
Predict the product and propose a suitable mechanism for the following reaction: amine, (1) CH₃I; (2) NaNH₂, NH₃ → ? [structure of the starting amine, N,N-dimethylbenzylamine, given in the paper]
Answer in brief
(2-Methylbenzyl)dimethylamine, C₁₀H₁₅N, by the Sommelet–Hauser rearrangement of benzyltrimethylammonium iodide.
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Topic notes: molecular rearrangements, with every Civil Services, IFoS and Geo-Scientist PYQ →
CoversSommelet–Hauser rearrangementnitrogen ylide[2,3]-sigmatropic shiftquaternary ammonium saltStevens rearrangement
All parts of Question 6
- 6(a) Reactivity of four alkenes towards electrophilic addition4 marks
- 6(b) Quaternisation, then Sommelet–Hauser rearrangement4 marks
- 6(c) Woodward–Fieser rules: three dienones4 marks
- 6(d) Carbonyl stretching bands of three lactones4 marks
- 6(e) Epoxidation of cholesterol with a peroxy acid4 marks
- 6(f) Norrish Type II reaction of two aryl alkyl ketones6 marks
- 6(g) Three isomeric esters C₄H₈O₂ from ¹H NMR6 marks
- 6(h) McLafferty rearrangement in a ketone, an acid and an ester6 marks
- 6(i) Stretching frequencies of six single bonds2 marks