Tetrabutylammonium hydroxide

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Tetrabutylammonium hydroxide
IUPAC name
tetrabutylammonium hydroxide
3D model (Jmol)
ECHA InfoCard 100.016.498
Molar mass 259.48 g·mol−1
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

Tetrabutylammonium hydroxide is the chemical compound with the formula (C4H9)4NOH, abbreviated Bu4NOH with the acronym TBAOH or TBAH. This species is employed as a solution in water or alcohols. It is a common base in organic chemistry. Relative to more conventional inorganic bases, such as KOH and NaOH, Bu4NOH is more soluble in organic solvents.[1]


Attempted isolation of Bu4NOH induces Hofmann elimination, leading to Bu3N and 1-butene. Solutions of Bu4NOH are typically contaminated with Bu3N for this reason.[1]

Treatment of Bu4NOH with a wide range of acids gives water and the other tetrabutylammonium salts:

Bu4NOH + HX → Bu4NX + H2O


Bu4NOH is a strong base that is used often under phase-transfer conditions to effect alkylations and deprotonations. Typical reactions include benzylation of amines and generation of dichlorocarbene from chloroform.

Bu4NOH can be neutralized with a variety of mineral acids to give lipophilic salts of the conjugate base. For example, treatment of Bu4NOH with disodium pyrophosphate, Na2H2P2O7, gives (Bu4N)3[HP2O7], which is soluble in organic solvents.[2] Similarly, neutralization of Bu4NOH with hydrofluoric acid affords an relatively water-free Bu4NF. This salt dissolves in organic solvents and is useful to desilylation.[3]


  1. ^ a b Bos, M. E. "Tetra-n-butylammonium Hydroxide" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289.
  2. ^ Woodside, A. B.; Huang, Z.; Poulter, C. D. (1993). "Trisammonium Geranyl Diphosphate". Org. Synth. ; Coll. Vol., 8, p. 616 
  3. ^ Kuwajima, I.; Nakamura, E. Hashimoto, K. (1990). "Silylation of Ketones with Ethyl Trimethylsilacetate: (Z)-3-Trimethylsiloxy-2-Pentene". Org. Synth. ; Coll. Vol., 7, p. 512