Addition of ammonia derivatives H₂N–Z (NCERT Table 8.2)अमोनिया व्युत्पन्न H₂N–Z का योग (NCERT सारणी 8.2)Addition of ammonia derivatives H₂N–Z (NCERT Table 8.2)
Class 12 Chemistry · Chapter 8 · interactive diagram
Parts and what they mean
- Carbonyl group of an aldehyde or ketone (ऐल्डिहाइड या कीटोन का कार्बोनिल समूह) — The N lone pair of H₂N–Z attacks its carbon.
- Ammonia derivative H₂N–Z (nucleophile) (अमोनिया व्युत्पन्न H₂N–Z (नाभिकस्नेही)) — Z = H, alkyl, aryl, OH, NH₂, C₆H₅NH, NHCONH₂ … The reaction is reversible and acid-catalysed.
- Addition intermediate (योगज मध्यवर्ती) — Rapid dehydration of this intermediate drives the equilibrium to the product.
- Product with C=N–Z (C=N–Z वाला उत्पाद) — Overall: addition followed by elimination of water (addition–elimination).
- Z = H: ammonia → imine (Z = H: अमोनिया → इमीन) — >C=NH
- Z = R: amine → substituted imine (Schiff’s base) (Z = R: ऐमीन → प्रतिस्थापित इमीन (शिफ़ क्षारक)) — >C=N–R, e.g. acetophenone + ethylamine (NCERT Intext 8.5 iv).
- Z = OH: hydroxylamine → oxime (Z = OH: हाइड्रॉक्सिलऐमीन → ऑक्सिम) — >C=N–OH
- Z = NH₂: hydrazine → hydrazone (Z = NH₂: हाइड्रैज़ीन → हाइड्रेज़ोन) — >C=N–NH₂ (first step of Wolff–Kishner reduction).
- Z = NHC₆H₅: phenylhydrazine → phenylhydrazone (Z = NHC₆H₅: फ़ेनिलहाइड्रैज़ीन → फ़ेनिलहाइड्रेज़ोन) — >C=N–NHC₆H₅
- 2,4-Dinitrophenylhydrazine (2,4-DNP) → 2,4-dinitrophenylhydrazone (2,4-डाइनाइट्रोफ़ेनिलहाइड्रैज़ीन (2,4-DNP) → 2,4-डाइनाइट्रोफ़ेनिलहाइड्रेज़ोन) — Yellow, orange or red solids — used to characterise (identify) aldehydes and ketones.
- Z = NHCONH₂: semicarbazide → semicarbazone (Z = NHCONH₂: सेमीकार्बेज़ाइड → सेमीकार्बेज़ोन) — Only the –NH₂ NOT attached to C=O reacts; the other is part of an amide (its lone pair is delocalised).
Original diagram drawn by Simple Learning Hub, based on the NCERT textbook. Report a mistake