Hoffmann bromamide degradation (one carbon less)हॉफमान ब्रोमेमाइड निम्नीकरण (एक कार्बन कम)Hoffmann bromamide degradation (one carbon less)
Class 12 Chemistry · Chapter 9 · interactive diagram
Parts and what they mean
- Alkyl or aryl group R (ऐल्किल या ऐरिल समूह R) — R is bonded to the carbonyl carbon in the amide…
- Carbonyl carbon (C=O) (कार्बोनिल कार्बन (C=O)) — This carbon is lost — it ends up in Na₂CO₃. That is why the amine has one carbon less.
- –NH₂ of the amide (ऐमाइड का –NH₂) — The N stays and becomes the amino group of the product.
- Migration of R from C to N (R का C से N पर स्थानांतरण) — NCERT: in this degradation the alkyl/aryl group migrates from the carbonyl carbon of the amide to the nitrogen atom.
- Br₂ in aqueous or ethanolic NaOH (जलीय या एथेनॉलिक NaOH में Br₂) — The reagent of Hoffmann bromamide degradation.
- Primary amine R–NH₂ (प्राथमिक ऐमीन R–NH₂) — Always a 1° amine, with one C less than the amide.
- By-products: Na₂CO₃, NaBr, H₂O (उप-उत्पाद: Na₂CO₃, NaBr, H₂O) — The lost carbonyl carbon appears as carbonate.
- Balanced equation (संतुलित समीकरण) — Atoms balance: C 1, O 5, N 1, H 6, Na 4, Br 2 on each side (besides R).
- Butanamide → propan-1-amine (ब्यूटेनेमाइड → प्रोपेन-1-ऐमीन) — Propanamine has 3 C, so the amide must have 4 C: butanamide (NCERT Example 9.3 i).
- Benzamide → aniline (बेन्ज़ेमाइड → ऐनिलीन) — Benzamide (7 C) gives the aromatic 1° amine with 6 C: aniline / benzenamine (NCERT Example 9.3 ii).
Original diagram drawn by Simple Learning Hub, based on the NCERT textbook. Report a mistake