Chemistry:Sodium amide

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Sodium amide
File:Sodium amide.png
Ball and stick, unit cell model of sodium amide
Names
IUPAC name
  • Sodium amide
  • Sodium azanide[1]
Other names
Sodamide
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
EC Number
  • 231-971-0
UNII
UN number 1390
Properties
NaNH
2
Molar mass 39.013 g·mol−1
Appearance Colourless crystals
Odor Ammonia-like
Density 1.39 g/cm3
Melting point 210 °C (410 °F; 483 K)[3]
Boiling point 400 °C (752 °F; 673 K)
Reacts
Solubility in liquid ammonia 40 mg/L
Acidity (pKa) 38 (conjugate acid)[2]
Structure[citation needed]
orthorhombic
Thermochemistry[citation needed]
66.15 J/(mol·K)
76.9 J/(mol·K)
−118.8 kJ/mol
−59 kJ/mol
Hazards
GHS pictograms GHS02: FlammableGHS05: Corrosive
GHS Signal word Danger
H261, H314, H412
P223, P231+232, P260, P264, P273, P280, P301+330+331, P303+361+353, P304+340+310, P305+351+338+310, P335+334, P363, P370+378, P402+404, P405, P501
NFPA 704 (fire diamond)
450 °C (842 °F; 723 K)[4]
Related compounds
Other anions
 Sodium bis(trimethylsilyl)amide
Other cations
Related compounds
 Ammonia
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Sodium amide, commonly called sodamide (systematic name sodium azanide), is the inorganic compound with the formula NaNH
2. It is a salt composed of the sodium cation and the azanide anion. It is a white solid which is dangerously reactive toward water, but commercial samples are typically gray due to the presence of small quantities of metallic iron from the manufacturing process. Such impurities do not usually affect the utility of the reagent. NaNH
2 conducts electricity in the fused state, its conductance being similar to that of NaOH in a similar state. NaNH
2 has been widely employed as a strong base in organic synthesis.

Preparation and structure

Sodium amide can be prepared by the reaction of sodium with ammonia gas,[5] but it is usually prepared by the reaction in liquid ammonia using iron(III) nitrate as a catalyst. The reaction is fastest at the boiling point of the ammonia (−33 °C (−27 °F; 240 K)). An electride, [Na(NH
3)
6]+
e−
, is formed as a reaction intermediate.[6]

2 Na + 2 NH
3 → 2 NaNH
2 + H
2

NaNH
2 is a salt-like material and as such, crystallizes as an infinite polymer.[7] The geometry about sodium is tetrahedral.[8] In ammonia, NaNH
2 forms conductive solutions, consistent with the presence of [Na(NH
3)
6]+
 and NH−
2 ions.

Uses

Sodium amide is mainly used as a strong base in organic chemistry, often suspended (it is insoluble[9]) in liquid ammonia solution. One of the main advantages to the use of sodium amide is its relatively low nucleophilicity. In the industrial production of indigo, sodium amide is a component of the highly basic mixture that induces cyclisation of N-phenylglycine. The reaction produces ammonia, which is typically recycled.[10]

Pfleger's synthesis of indigo dye.

Dehydrohalogenation

Sodium amide is a standard base for dehydrohalogenations.[11] It induces the loss of two equivalents of hydrogen bromide from a vicinal dibromoalkane to give a carbon–carbon triple bond, as in a preparation of phenylacetylene.[12] Usually two equivalents of sodium amide yields the desired alkyne. Three equivalents are necessary in the preparation of a terminal alkynes because the terminal CH of the resulting alkyne protonates an equivalent amount of base.

300px

Hydrogen chloride and ethanol can also be eliminated in this way, as in the preparation of 1-ethoxy-1-butyne.[13][14][15][16][17]

500px

Cyclization reactions

Where there is no β-hydrogen to be eliminated, cyclic compounds may be formed, as in the preparation of methylenecyclopropane below.[18]

400px

Cyclopropenes, aziridines and cyclobutanes may be formed in a similar manner.[19][20][21]

Deprotonation of carbon and nitrogen acids

Carbon acids which can be deprotonated by sodium amide in liquid ammonia include:

Acetylacetone loses two protons to form a dianion.[32][33] Sodium amide will also deprotonate indole and piperidine.[34][35]

It is however poorly soluble in solvents other than ammonia. Its use has been superseded by the related reagents sodium hydride, sodium bis(trimethylsilyl)amide (NaHMDS), and lithium diisopropylamide (LDA).

Other reactions

Safety

Sodium amide is a common reagent with a long history of laboratory use.[11] It reacts violently on contact with water, producing ammonia and sodium hydroxide:

NaNH
2 + H
2O → NH
3 + NaOH

When burned in oxygen, it will give oxides of sodium (which react with the produced water, giving sodium hydroxide) along with nitrogen oxides:

4 NaNH
2 + 5 O
2 → 4 NaOH + 4 NO + 2 H
2O
4 NaNH
2 + 7 O
2 → 4 NaOH + 4 NO
2 + 2 H
2O

In the presence of limited quantities of air and moisture, such as in a poorly closed container, explosive mixtures of peroxides may form.[39] This is accompanied by a yellowing or browning of the solid. As such, sodium amide is to be stored in a tightly closed container, under an atmosphere of an inert gas. Sodium amide samples which are yellow or brown in color represent explosion risks.[40]

References

  1. ↑ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version:  (2006–) "amides". doi:10.1351/goldbook.A00266
  2. ↑ Buncel, E.; Menon, B. (1977). "Carbanion mechanisms: VII. Metallation of hydrocarbon acids by potassium amide and potassium methylamide in tetrahydrofuran and the relative hydride acidities". Journal of Organometallic Chemistry 141 (1): 1–7. doi:10.1016/S0022-328X(00)90661-2. 
  3. ↑ 3.0 3.1 Sigma-Aldrich Co., Sodium amide. Retrieved on 20 March 2026.
  4. ↑ 4.0 4.1 "SDS - Sodium amide" (pdf). ThermoFisher Scientific. 19 December 2025. pp. 3-5. https://www.fishersci.com/store/msds?partNumber=AC339240250&productDescription=SODIUM+AMIDE+25GR&vendorId=VN00032119&countryCode=US&language=en. 
  5. ↑ Bergstrom, F. W. (1955). "Sodium amide". Organic Syntheses. http://www.orgsyn.org/demo.aspx?prep=cv3p0778. ; Collective Volume, 3, pp. 778 
  6. ↑ Greenlee, K. W.; Henne, A. L.. "Sodium Amide". Inorganic Syntheses. 2. pp. 128–135. doi:10.1002/9780470132333.ch38. ISBN 9780470132333. 
  7. ↑ Zalkin, A.; Templeton, D. H. (1956). "The Crystal Structure Of Sodium Amide". Journal of Physical Chemistry 60 (6): 821–823. doi:10.1021/j150540a042. 
  8. ↑ Wells, A. F. (1984). Structural Inorganic Chemistry. Oxford: Clarendon Press. ISBN 0-19-855370-6. 
  9. ↑ Audrieth, Ludwig F.; Kleinberg, Jacob (1953). Non-aqueous solvents. New York: John Wiley & Sons. p. 79. https://archive.org/details/cftri.2662nonaqueoussolven0000ludw/page/79/. 
  10. ↑ Lange, L.; Treibel, W. (2005). "Ullmann's Encyclopedia of Industrial Chemistry". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a24_267. 
  11. ↑ 11.0 11.1 Belletire, John L.; Rauh, R. Jeffery (2001). "Sodium Amide". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rs041. ISBN 0-471-93623-5. 
  12. ↑ Campbell, K. N.; Campbell, B. K. (1950). "Phenylacetylene". Organic Syntheses 30: 72. http://www.orgsyn.org/demo.aspx?prep=cv4p0763. ; Collective Volume, 4, pp. 763 
  13. ↑ Jones, E. R. H.; Eglinton, G.; Whiting, M. C.; Shaw, B. L. (1954). "Ethoxyacetylene". Organic Syntheses 34: 46. http://www.orgsyn.org/demo.aspx?prep=cv4p0404. ; Collective Volume, 4, pp. 404 
  14. ↑ Bou, A.; Pericàs, M. A.; Riera, A.; Serratosa, F. (1987). "Dialkoxyacetylenes: di-tert-butoxyethyne, a valuable synthetic intermediate". Organic Syntheses 65: 58. http://www.orgsyn.org/demo.aspx?prep=cv8p0161. ; Collective Volume, 8, pp. 161 
  15. ↑ Magriotis, P. A.; Brown, J. T. (1995). "Phenylthioacetylene". Organic Syntheses 72: 252. http://www.orgsyn.org/demo.aspx?prep=cv9p0656. ; Collective Volume, 9, pp. 656 
  16. ↑ Ashworth, P. J.; Mansfield, G. H.; Whiting, M. C. (1955). "2-Butyn-1-ol". Organic Syntheses 35: 20. http://www.orgsyn.org/demo.aspx?prep=cv4p0128. ; Collective Volume, 4, pp. 128 
  17. ↑ Newman, M. S.; Stalick, W. M. (1977). "1-Ethoxy-1-butyne". Organic Syntheses 57: 65. http://www.orgsyn.org/demo.aspx?prep=cv6p0564. ; Collective Volume, 6, pp. 564 
  18. ↑ Salaun, J. R.; Champion, J.; Conia, J. M. (1977). "Cyclobutanone from methylenecyclopropane via oxaspiropentane". Organic Syntheses 57: 36. http://www.orgsyn.org/demo.aspx?prep=cv6p0320. ; Collective Volume, 6, pp. 320 
  19. ↑ Nakamura, M.; Wang, X. Q.; Isaka, M.; Yamago, S.; Nakamura, E. (2003). "Synthesis and (3+2)-cycloaddition of a 2,2-dialkoxy-1-methylenecyclopropane: 6,6-dimethyl-1-methylene-4,8-dioxaspiro(2.5)octane and cis-5-(5,5-dimethyl-1,3-dioxan-2-ylidene)hexahydro-1(2H)-pentalen-2-one". Organic Syntheses 80: 144. http://www.orgsyn.org/demo.aspx?prep=v80p0144. 
  20. ↑ Bottini, A. T.; Olsen, R. E. (1964). "N-Ethylallenimine". Organic Syntheses 44: 53. http://www.orgsyn.org/demo.aspx?prep=cv5p0541. ; Collective Volume, 5, pp. 541 
  21. ↑ Skorcz, J. A.; Kaminski, F. E. (1968). "1-Cyanobenzocyclobutene". Organic Syntheses 48: 55. http://www.orgsyn.org/demo.aspx?prep=cv5p0263. ; Collective Volume, 5, pp. 263 
  22. ↑ Saunders, J. H. (1949). "1-Ethynylcyclohexanol". Organic Syntheses 29: 47. http://www.orgsyn.org/demo.aspx?prep=cv3p0416. ; Collective Volume, 3, pp. 416 
  23. ↑ Peterson, P. E.; Dunham, M. (1977). "(Z)-4-Chloro-4-hexenyl trifluoroacetate". Organic Syntheses 57: 26. http://www.orgsyn.org/demo.aspx?prep=cv6p0273. ; Collective Volume, 6, pp. 273 
  24. ↑ Kauer, J. C.; Brown, M. (1962). "Tetrolic acid". Organic Syntheses 42: 97. http://www.orgsyn.org/demo.aspx?prep=cv5p1043. ; Collective Volume, 5, pp. 1043 
  25. ↑ Coffman, D. D. (1940). "Dimethylethynylcarbinol". Organic Syntheses 20: 40. http://www.orgsyn.org/demo.aspx?prep=cv3p0320. ; Collective Volume, 3, pp. 320 
  26. ↑ Hauser, C. R.; Adams, J. T.; Levine, R. (1948). "Diisovalerylmethane". Organic Syntheses 28: 44. http://www.orgsyn.org/demo.aspx?prep=cv3p0291. ; Collective Volume, 3, pp. 291 
  27. ↑ Vanderwerf, C. A.; Lemmerman, L. V. (1948). "2-Allylcyclohexanone". Organic Syntheses 28: 8. http://www.orgsyn.org/demo.aspx?prep=cv3p0044. ; Collective Volume, 3, pp. 44 
  28. ↑ Hauser, C. R.; Dunnavant, W. R. (1960). "α,β-Diphenylpropionic acid". Organic Syntheses 40: 38. http://www.orgsyn.org/demo.aspx?prep=cv5p0526. ; Collective Volume, 5, pp. 526 
  29. ↑ Kaiser, E. M.; Kenyon, W. G.; Hauser, C. R. (1967). "Ethyl 2,4-diphenylbutanoate". Organic Syntheses 47: 72. http://www.orgsyn.org/demo.aspx?prep=cv5p0559. ; Collective Volume, 5, pp. 559 
  30. ↑ Wawzonek, S.; Smolin, E. M. (1951). "α,β-Diphenylcinnamonitrile". Organic Syntheses 31: 52. http://www.orgsyn.org/demo.aspx?prep=cv4p0387. ; Collective Volume, 4, pp. 387 
  31. ↑ Murphy, W. S.; Hamrick, P. J.; Hauser, C. R. (1968). "1,1-Diphenylpentane". Organic Syntheses 48: 80. http://www.orgsyn.org/demo.aspx?prep=cv5p0523. ; Collective Volume, 5, pp. 523 
  32. ↑ Hampton, K. G.; Harris, T. M.; Hauser, C. R. (1971). "Phenylation of diphenyliodonium chloride: 1-phenyl-2,4-pentanedione". Organic Syntheses 51: 128. http://www.orgsyn.org/demo.aspx?prep=cv6p0928. ; Collective Volume, 6, pp. 928 
  33. ↑ Hampton, K. G.; Harris, T. M.; Hauser, C. R. (1967). "2,4-Nonanedione". Organic Syntheses 47: 92. http://www.orgsyn.org/demo.aspx?prep=cv5p0848. ; Collective Volume, 5, pp. 848 
  34. ↑ Potts, K. T.; Saxton, J. E. (1960). "1-Methylindole". Organic Syntheses 40: 68. http://www.orgsyn.org/demo.aspx?prep=cv5p0769. ; Collective Volume, 5, pp. 769 
  35. ↑ "N-β-Naphthylpiperidine". Organic Syntheses 40: 74. 1960. http://www.orgsyn.org/demo.aspx?prep=cv5p0816. ; Collective Volume, 5, pp. 816 
  36. ↑ Brazen, W. R.; Hauser, C. R. (1954). "2-Methylbenzyldimethylamine". Organic Syntheses 34: 61. http://www.orgsyn.org/demo.aspx?prep=cv4p0585. ; Collective Volume, 4, pp. 585 
  37. ↑ Allen, C. F. H.; VanAllan, J. (1944). "Phenylmethylglycidic ester". Organic Syntheses 24: 82. http://www.orgsyn.org/demo.aspx?prep=cv3p0727. ; Collective Volume, 3, pp. 727 
  38. ↑ Allen, C. F. H.; VanAllan, J. (1942). "2-Methylindole". Organic Syntheses 22: 94. http://www.orgsyn.org/demo.aspx?prep=cv3p0597. ; Collective Volume, 3, pp. 597 
  39. ↑ Clark, Donald E (2001). "Peroxides and peroxide-forming compounds". Chemical Health and Safety 8 (5): 12–22. doi:10.1016/S1074-9098(01)00247-7. ISSN 1074-9098. 
  40. ↑ "Sodium amide Handling". Princeton. https://ehs.princeton.edu/laboratory-research/chemical-safety/chemical-specific-protocols/sodium-amide. 



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