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Primary alcohol + HBr (SN2) template
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Butan-1-ol is protonated by HBr (from NaBr and conc. H₂SO₄) and bromide displaces water to give 1-bromobutane, with no carbocation.
Mechanism step by step
Protonation makes water the leaving group; bromide then attacks the carbon from the back
- Protonation – HBr protonates the OH group
- Backside attack – Br⁻ displaces water in one step
Key points
- OH⁻ is a poor leaving group; H₂O (after protonation) is a good one.
- Primary alcohols react by SN2: a primary carbocation is too unstable to form.
- Tertiary alcohols react by SN1 through the carbocation, fast even at room temperature (compare the Lucas test).
- PBr₃ or SOCl₂ convert alcohols to halides without strong acid and without rearrangement.
Drawn with 37 atoms, 7 arrows, 6 shapes – every one editable in MolDraw.
Sources
How to use this template
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Frequently asked questions
Is the Primary alcohol + HBr (SN2) template free?
You can preview the Primary alcohol + HBr (SN2) template here and open and edit it in MolDraw for free. Downloading or exporting it is part of MolDraw Pro, together with the other premium templates.
Can I edit the Primary alcohol + HBr (SN2) template?
Yes. It opens as an ordinary MolDraw drawing, so every structure, arrow, label and colour can be changed, and you can add your own content around it.
Is the chemistry checked?
Every structure is checked with RDKit and every curly arrow passes MolDraw’s electron-flow audit. The sources used are listed on this page.
What is a curly-arrow mechanism template?
A ready-made drawing of a reaction mechanism in which curved arrows show where electron pairs move in each step. You can open it in MolDraw, change the substrate and reuse it.