--- title: "Hell–Volhard–Zelinsky reaction Template | MolDraw" url: https://www.moldraw.com/templates/hell-volhard-zelinsky/ description: "Hell–Volhard–Zelinsky reaction template: PBr₃ makes the acyl bromide, which enolises; the enol attacks Br₂ and hydrolysis gives 2-bromopropanoic acid.…" lang: en publisher: Scidart Academy generated: 2026-10-28 --- [MolDraw](https://www.moldraw.com/) › [Templates](https://www.moldraw.com/templates/) › [Name reactions](https://www.moldraw.com/templates/name-reactions/) › Hell–Volhard–Zelinsky reaction [Name reactions](https://www.moldraw.com/templates/name-reactions/)Premium # Hell–Volhard–Zelinsky reaction template ![Hell–Volhard–Zelinsky reaction template: PBr₃ makes the acyl bromide, which enolises; the enol attacks Br₂ and hydrolysis gives 2-bromopropanoic acid.](https://www.moldraw.com/templates/hell-volhard-zelinsky.webp) [Edit in MolDraw](https://www.moldraw.com/)Download with Pro Premium template. Preview and edit it free in MolDraw; downloading and exporting it is part of [MolDraw Pro](https://www.moldraw.com/pricing). PBr₃ makes the acyl bromide, which enolises; the enol attacks Br₂ and hydrolysis gives 2-bromopropanoic acid. ## Mechanism step by step α-Bromination of a carboxylic acid through its acyl bromide enol 1. **Protonation** – PBr₃ has made the acyl bromide; HBr protonates its C=O 2. **Enol** – Loss of an α-H 3. **α-Bromination** – The enol attacks Br₂ 4. **Deprotonation** – The α-bromo acyl bromide ## Key points - Carboxylic acids barely enolise; the acyl bromide enolises readily. - The α-bromo acyl bromide swaps Br for OH with more acid, so PBr₃ is catalytic. - Water at the end hydrolyses the acyl bromide to the acid (addition–elimination). - The α-bromo acid is a route to α-amino acids (NH₃) and α-hydroxy acids. Drawn with 66 atoms, 15 arrows, 6 shapes – every one editable in MolDraw. ## Sources - [Hell, Ber. Dtsch. Chem. Ges. 1881, 14, 891](https://doi.org/10.1002/cber.188101401187) Original paper - [Kürti & Czakó, Strategic Applications of Named Reactions in Organic Synthesis, Elsevier 2005](https://openlibrary.org/isbn/9780124297852) Textbook - [Clayden, Greeves & Warren, Organic Chemistry, 2nd ed., OUP 2012](https://openlibrary.org/isbn/9780199270293) Textbook ## How to use this template 1. Press **Edit in MolDraw**. The template opens on the canvas of the free MolDraw editor. 2. Change anything: move structures, edit atoms and labels, recolour highlights or delete what you do not need. 3. Add your own structures, arrows and text next to it, or combine several templates on one page. 4. Export the drawing as PNG, SVG or PDF for slides, worksheets, theses and papers. ## Frequently asked questions ### Is the Hell–Volhard–Zelinsky reaction template free? You can preview the Hell–Volhard–Zelinsky reaction 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 Hell–Volhard–Zelinsky reaction 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. ### Which name reactions are included? Over seventy, covering the reactions most often asked in school-leaving exams (A-level, IB, CBSE, JEE and NEET) and first-year university courses, including condensations, rearrangements, oxidations, reductions and aromatic substitutions. ## More name reactions templates [**Fischer esterification**Free · Name reactions](https://www.moldraw.com/templates/fischer-esterification/)[**Grignard addition to a ketone**Free · Name reactions](https://www.moldraw.com/templates/grignard-addition/)[**Michael addition**Free · Name reactions](https://www.moldraw.com/templates/michael-addition/)[**Diels–Alder reaction**Premium · Name reactions](https://www.moldraw.com/templates/diels-alder/)[**Friedel–Crafts acylation**Premium · Name reactions](https://www.moldraw.com/templates/friedel-crafts-acylation/)[**Claisen condensation**Premium · Name reactions](https://www.moldraw.com/templates/claisen-condensation/)[**Friedel–Crafts alkylation**Premium · Name reactions](https://www.moldraw.com/templates/friedel-crafts-alkylation/)[**Cannizzaro reaction**Premium · Name reactions](https://www.moldraw.com/templates/cannizzaro-reaction/) ## Related pages [**Hell–Volhard–Zelinsky reaction: reaction guide**Mechanism, conditions and exam notes](https://www.moldraw.com/reaction/hell-volhard-zelinsky-reaction/)[**Curved Arrow Mechanism Worksheet**Free printable worksheet](https://www.moldraw.com/educational-materials/curved-arrow-mechanism-worksheet/)[**Predict the Product Worksheet: Organic Reactions**Free printable worksheet](https://www.moldraw.com/educational-materials/predict-the-product-worksheet/)[**All Name reactions templates**72 templates](https://www.moldraw.com/templates/name-reactions/)[**All chemistry templates**370 templates in 29 categories](https://www.moldraw.com/templates/) MolDraw Pro Download all 370 templates - Export the 291 premium templates as PNG, SVG or PDF - AI chemistry assistant - Structure scanning from images - Cloud save and teaching slides [See Pro plans](https://www.moldraw.com/pricing) Free templates stay free. Every template can be opened and edited in MolDraw.