# Sodium amide
**Sodium amide**, also called sodamide (formula NaNH₂, CAS 7782-92-5), is an inorganic sodium salt composed of a sodium cation and an azanide anion, used as a strong base and nucleophilic reagent in organic synthesis.[1](https://pubchem.ncbi.nlm.nih.gov/compound/24533) It is an odorless, colorless to grayish solid, denser than water, that reacts violently with water to give sodium hydroxide and ammonia.[1](https://pubchem.ncbi.nlm.nih.gov/compound/24533) • [2](https://labchem-wako.fujifilm.com/jp/product/detail/W01W0119-1194.html)
| Key fact | Detail |
|---|---|
| Formula and molar mass | NaNH₂, 39.013 g/mol; sodium salt of the azanide anion [NH₂]⁻[1](https://pubchem.ncbi.nlm.nih.gov/compound/24533) |
| Melting point | 210 °C; begins to volatilize at 400 °C and decomposes into its elements between 500 and 600 °C[3](https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-amide) |
| Density and solubility | 1.39 g/cm³ at 20 °C; solubility in liquid ammonia about 0.1% at 20 °C; decomposes in water and alcohol[3](https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-amide) |
| Preparation | Reaction of sodium metal with dry gaseous ammonia at about 350 °C, or with liquid ammonia using ferric nitrate as catalyst[3](https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-amide) |
| Principal synthetic use | Strong, poorly nucleophilic base for deprotonating terminal alkynes and other acidic C–H bonds in anhydrous liquid ammonia[4](https://www.sciencedirect.com/science/article/pii/S0926961496800335) |
| Industrial use | Condensing agent in the Heumann–Pfleger synthesis of indigo, operating at around 200 °C[5](https://link.springer.com/article/10.1007/s00706-026-03466-1) |
| Handling hazard | Reacts explosively with water; air oxidation forms products that make the mixture highly explosive, signaled by a yellow or brownish color[6](https://www.orgsyn.org/demo.aspx?prep=CV3P0778) |
## Preparation
The classical industrial route passes dry ammonia gas over molten metallic sodium at about 350 °C.[3](https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-amide) In the laboratory, sodium amide is usually formed in situ: sodium is added to anhydrous liquid ammonia, often with a small amount of hydrated ferric nitrate as catalyst, and the reaction is complete when the intense blue color of the sodium–ammonia solution disappears and a light gray suspension of the amide remains.[6](https://www.orgsyn.org/demo.aspx?prep=CV3P0778) • [7](https://www.orgsyn.org/demo.aspx?prep=CV4P0404) A molten-scale [Organic Syntheses](https://www.edgepedia.org/organic-syntheses) procedure using about 175 g of sodium in a nickel crucible at 350–360 °C gives yields of 90–95%, with the product stored under a petroleum fraction; checkers kept specimens this way for 3 years without appreciable loss of activity.[6](https://www.orgsyn.org/demo.aspx?prep=CV3P0778) Other reported routes include the action of ammonia on sodium alloys and the electrolysis of sodium cyanide solution in liquid ammonia with a sodium amalgam electrode.[6](https://www.orgsyn.org/demo.aspx?prep=CV3P0778)
## Physical and chemical properties
Sodium amide melts at 210 °C. A thermal decomposition study found that it is not decomposed below 230 °C, though it undergoes structural changes near 120 °C and 150 °C before melting at 210 °C.[8](https://www.sciencedirect.com/science/article/pii/S0360319916335649) It begins to volatilize at 400 °C and decomposes into its elements between 500 and 600 °C.[3](https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-amide) Its solubility in liquid ammonia at 20 °C is only about 0.1%, so reactions in that solvent are run as suspensions.[3](https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-amide)
The compound is a very strong base. Hydrolysis is violent: contact with water or alcohol decomposes it to sodium hydroxide and ammonia.[2](https://labchem-wako.fujifilm.com/jp/product/detail/W01W0119-1194.html) • [3](https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-amide) Molten (fused) sodium amide is a aggressive solvent in its own right, dissolving metallic magnesium, zinc, molybdenum, tungsten, quartz, glass, and silicates.[3](https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-amide)
## Use in organic synthesis
**Deprotonation chemistry.** Sodium amide is widely used as a proton abstractor because of its strong basicity and comparatively low nucleophilicity, allowing selective removal of acidic C–H bonds to form organosodium species.[9](https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/ejic.202400200) Its signature application is the deprotonation of terminal alkynes in anhydrous liquid ammonia: the acidic acetylenic proton is removed to give the acetylide anion, which is then reacted with electrophiles such as alkyl halides.[4](https://www.sciencedirect.com/science/article/pii/S0926961496800335) The same liquid-ammonia methodology metallates other weak carbon acids; diphenylmethane is metallated by NaNH₂ and alkylated in 90–95% yields, the indole anion is methylated to 1-methylindole in high yield, and the disodio salts of 1,3-diketones are prepared and then alkylated or acylated.[4](https://www.sciencedirect.com/science/article/pii/S0926961496800335) A fused eutectic of sodium amide and potassium amide has also been used as a reaction medium for organic syntheses, including aminations involving chlorine compounds and naphthalene derivatives.[10](https://pubmed.ncbi.nlm.nih.gov/20983300/)
**Indigo manufacture.** Sodium amide's largest historical industrial role was in the Heumann–Pfleger synthesis of indigo, patented in 1901 (DRP 137955). N-phenylglycine, made from aniline, formaldehyde, and hydrocyanic acid, is fused in an alkaline melt with sodium amide, which acts as a condensing agent that facilitates ring closure to indoxyl, the precursor from which two molecules couple to indigo.[5](https://link.springer.com/article/10.1007/s00706-026-03466-1) The process ran at only around 200 °C, well below the 300 °C of the first Heumann synthesis of 1890, which made it cheaper, less error-prone, and higher yielding.[5](https://link.springer.com/article/10.1007/s00706-026-03466-1) In the industrial variant described in a contemporary chemical encyclopedia, roughly 160–170 kg of sodium amide are charged into the fusion at about 100 °C, followed by potassium phenylglycinate under 4–5 atm pressure; the ammonia released is recycled to sodium amide manufacture, and indigo yields reach 90% of theory.[11](https://bluefringes.com/textual_sources/enzyklopadie-der-technischen-chemie-band-6-scanned-pages-237-259-printed-pages-233-255/) The related Hoechst–BASF process of 1904 also used a hot melt of sodium hydroxide with sodium amide to form indoxyl, though BASF replaced the expensive sodium amide with cheaper calcium oxide in 1905.[5](https://link.springer.com/article/10.1007/s00706-026-03466-1)
## Related chemistry and current directions
The amide anion's conjugate acid is ammonia, which places NaNH₂ among the strongest bases usable in liquid ammonia as solvent. Bulky sodium amides, such as sodium 2,2,6,6-tetramethylpiperidide and sodium dicyclohexylamide combined with polyamine donors like PMDETA, have been developed as proton abstractors for [catalytic hydrogen isotope exchange](https://www.edgepedia.org/catalytic-hydrogen-isotope-exchange) on arenes, using deuterated benzene as the deuterium source; sodium amides are emerging as substitutes for the more common lithium amides.[9](https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/ejic.202400200) Sodium amide has also been investigated for hydrogen production through ammonia decomposition, a reaction of interest for supplying hydrogen in a low-carbon energy economy.[12](https://pubs.acs.org/doi/10.1021/ja5042836)
## Safety
Sodium amide combines with oxygen and reacts explosively with water. Exposure to limited amounts of air, as in imperfectly sealed containers, forms products that render the mixture highly explosive; the development of a yellow or brownish color signals oxidation, and such material should be destroyed at once, conveniently by covering it with benzene, toluene, or kerosene and slowly adding dilute ethanol with stirring.[6](https://www.orgsyn.org/demo.aspx?prep=CV3P0778) Commercial material is hygroscopic, hydrolyzed by atmospheric moisture, and readily oxidized in air, so it is stored sealed under inert gas.[2](https://labchem-wako.fujifilm.com/jp/product/detail/W01W0119-1194.html)
## References
1. [Sodium amide, CID 24533, PubChem](https://pubchem.ncbi.nlm.nih.gov/compound/24533)
2. [Sodium Amide product information, FUJIFILM Wako Pure Chemical](https://labchem-wako.fujifilm.com/jp/product/detail/W01W0119-1194.html)
3. [Sodium amide, chemical and physical properties, PubChem (HSDB, CAMEO, USCG CHRIS data)](https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-amide)
4. [Sodium amide in organic synthesis, Industrial Chemistry Library, Vol. 8 (1996), ScienceDirect](https://www.sciencedirect.com/science/article/pii/S0926961496800335)
5. [Indigo: history of its synthesis, Monatshefte für Chemie (2026)](https://link.springer.com/article/10.1007/s00706-026-03466-1)
6. [Sodium amide, Organic Syntheses, Coll. Vol. 3, p. 778 (Org. Synth. 1940, 20, 86)](https://www.orgsyn.org/demo.aspx?prep=CV3P0778)
7. [Ethoxyacetylene, Organic Syntheses, Coll. Vol. 4, p. 404 (Org. Synth. 1954, 34, 46)](https://www.orgsyn.org/demo.aspx?prep=CV4P0404)
8. [Thermal decomposition of sodium amide, International Journal of Hydrogen Energy, ScienceDirect](https://www.sciencedirect.com/science/article/pii/S0360319916335649)
9. [Development of Sterically Hindered and Basic Sodium Amides for Catalytic Hydrogen Isotope Exchange, European Journal of Inorganic Chemistry (2024)](https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/ejic.202400200)
10. [The use of the fused eutectic of sodium amide and potassium amide in organic syntheses, F. W. Bergstrom, H. G. Sturz, H. W. Tracy, J. Org. Chem. 11, 239 (1946)](https://pubmed.ncbi.nlm.nih.gov/20983300/)
11. [Enzyklopädie der technischen Chemie, Band 6, scanned pages 237–259, Blue Fringes](https://bluefringes.com/textual_sources/enzyklopadie-der-technischen-chemie-band-6-scanned-pages-237-259-printed-pages-233-255/)
12. [Hydrogen Production from Ammonia Using Sodium Amide, Journal of the American Chemical Society](https://pubs.acs.org/doi/10.1021/ja5042836)
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*Topic: Encyclopedia › Physical world and mathematics › Chemistry › Elements and inorganic substances › Halides, nitrides, and carbides › Nitrides and oxynitride materials › Alkali and alkaline-earth nitrides*
*Initially written Sep 17, 2026 · Reviewed: Oct 15, 2026 · Edited: Oct 15, 2026 · Last review: Oct 15, 2026*
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