NaNH2

Sodium amide, NaNH2, is a white, moisture‑sensitive solid that functions as a very strong inorganic base and nucleophile. It is most commonly used in anhydrous ammonia as a solvent, where it exists as the amide ion NH2− paired with Na+. Its basicity and nucleophilicity make it useful for deprotonation and generation of carbanions in organic synthesis. NaNH2 reacts readily with water and oxygen, releasing ammonia and causing caustic, potentially hazardous conditions.

Preparation and handling

Sodium amide is typically prepared by direct reaction of sodium metal with liquid ammonia: 2 Na + 2 NH3 → 2 NaNH2 + H2. The material is handled under strictly dry, inert conditions and stored sealed to prevent contact with moisture. In the presence of water or moisture, NaNH2 hydrolyzes and can release ammonia and sodium hydroxide, with violent or exothermic consequences if exposed to air or water.

Reactions and applications

NaNH2 is a preferred base for deprotonating terminal alkynes to form sodium acetylide (alkynide) salts in ammonia solvent. These acetylide species can undergo alkylation with primary alkyl halides to forge new carbon–carbon bonds, followed by acidic workup to yield substituted alkynes. The reagent also deprotonates other relatively weak acids to generate carbanions, enabling a variety of carbon‑carbon and related transformations. In practice, reactions are typically conducted under strictly anhydrous conditions and in an appropriate solvent system to maintain base activity and control reactivity.

Safety

NaNH2 is highly caustic and reacts violently with water and air. It must be handled under inert atmosphere, with suitable protective equipment, in dry solvents and containers. Proper quenching and disposal procedures are required to manage hydrolysis products and residual base.