CAS number 110-91-8 YesY
KEGG C14452 N
RTECS number QD6475000
Jmol-3D images Image 1
Molecular formula C4H9NO
Molar mass 87.1 g/mol
Appearance Colorless liquid
Density 1.007 g/cm3
Melting point

-5 °C, 268 K, 23 °F

Boiling point

129 °C, 402 K, 264 °F

Solubility in water miscible
Acidity (pKa) 8.36[1]
R-phrases R10 R20/21/22 R34
S-phrases (S1/2) S23 S36 S45
Main hazards Flammable, Corrosive
NFPA 704
NFPA 704.svg
Flash point 31 °C
275 °C
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Morpholine is an organic chemical compound having the chemical formula O(CH2CH2)2NH. This heterocycle, pictured at right, features both amine and ether functional groups. Because of the amine, morpholine is a base; its conjugate acid is called morpholinium. For example, neutralizing morpholine with hydrochloric acid makes the salt morpholinium chloride.



Morpholine may be produced by the dehydration of diethanolamine with sulfuric acid:[2]

Morpholine from DEA.png


Industrial applications

Morpholine is a common additive, in parts per million concentrations, for pH adjustment in both fossil fuel and nuclear power plant steam systems. Morpholine is used because its volatility is about the same as water, so once it is added to the water, its concentration becomes distributed rather evenly in both the water and steam phases. Its pH adjusting qualities then become distributed throughout the steam plant to provide corrosion protection. Morpholine is often used in conjunction with low concentrations of hydrazine or ammonia to provide a comprehensive all-volatile treatment chemistry for corrosion protection for the steam systems of such plants. Morpholine decomposes reasonably slowly in the absence of oxygen at the high temperatures and pressures in these steam systems.

Organic synthesis

Morpholine undergoes most chemical reactions typical for other secondary amines, though the presence of the ether oxygen withdraws electron density from the nitrogen, rendering it less nucleophilic (and less basic) than structurally similar secondary amines such as piperidine. For this reason, it forms a stable chloramine (CAS#23328-69-0).[3]

It is commonly used to generate enamines.[4]

Morpholine is widely used in organic synthesis. For example, it is a building block in the preparation of the antibiotic linezolid and the anticancer agent gefitinib (Iressa).

In research and in industry, the low cost and polarity of morpholine lead to its common use as a solvent for chemical reactions.


Most (as above) is widespread in Europe and the USA; accordingly, producers in Europe and the USA are able to cover the domestic and export markets.


As a fruit coating

Morpholine is used as a chemical emulsifier in the process of waxing fruit. Naturally, fruits make waxes to protect against insects and fungal contamination, but this can be lost as the fruit is cleaned. A small amount of new wax is applied to replace it. Morpholine is used as an emulsifier and solubility aid for shellac, which is used as a wax for fruit coating.[5]

As a component in fungicides

Morpholine derivatives used as agricultural fungicides in cereals are known as ergosterol biosynthesis inhibitors.


  1. ^ Hall, H.K., J. Am. Chem. Soc., 1957, 79, 5441.
  2. ^ Klaus Weissermel, Hans-Jürgen Arpe, Charlet R. Lindley, Stephen Hawkins (2003). "Chap. 7. Oxidation Products of Ethylene". Industrial Organic Chemistry. Wiley-VCH. pp. 159–161. ISBN 3527305785. 
  3. ^ Lindsay Smith, J. R.; McKeer, L. C.; Taylor, J. M. (1993), "4-Chlorination of Electron-Rich Benzenoid Compounds: 2,4-Dichloromethoxybenzene", Org. Synth., ; Coll. Vol. 8: 167 
  4. ^ Noyori, R.; Yokoyama, K.; Hayakawa, Y. (1988), "Cyclopentenones from α,α'-Dibromoketones and Enamines: 2,5-Dimethyl-3-Phenyl-2-Cyclopenten-1-one", Org. Synth., ; Coll. Vol. 6: 520 
  5. ^ Raymond G. McGuire; Dimitrios A. Dimitroglou,"Evaluation of Shellac and Sucrose Ester Fruit Coating Formulations that Support Biological Control of Post-harvest Grapefruit Decay". Bio-control Science and Technology, Volume 9, Issue 1 March 1999 , pages 53 - 65

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Look at other dictionaries:

  • Morpholine — Général Nom IUPAC tétrahydro 1,4 oxazine No CAS …   Wikipédia en Français

  • morpholine — morfolinas statusas T sritis chemija apibrėžtis Heterociklinis junginys. formulė HN:(CH₂CH₂)₂:O atitikmenys: angl. morpholine rus. морфолин …   Chemijos terminų aiškinamasis žodynas

  • morpholine — /mawr feuh leen , lin/, n. Chem. a colorless, hygroscopic liquid, C4H9NO, used chiefly as a solvent for dyes, resins, and waxes. [1885 90; MORPH + OL2 + INE2] * * * …   Universalium

  • morpholine — noun A six membered, saturated heterocycle tetrahydro 1,4 oxazine containing four carbon atoms, one nitrogen and one oxygen atom; it has a number of industrial applications Syn: tetrahydrooxazine See Also: morpholinium …   Wiktionary

  • morpholine — mor·pho·line mȯr fə .lēn, lən n an oily cyclic secondary amine C4H9NO made from ethylene oxide and ammonia and used chiefly as a solvent and emulsifying agent …   Medical dictionary

  • morpholine — n. (Chemistry) colorless organic liquid used as a deacidifying agent (Na . (CH 2 ) 2 . O . (CH 2 ) 2) …   English contemporary dictionary

  • morpholine — mor·pho·line …   English syllables

  • morpholine —  n.f. Fongicide …   Le dictionnaire des mots absents des autres dictionnaires

  • morpholine — ˌlēn, lə̇n noun ( s) Etymology: International Scientific Vocabulary morphol (International Scientific Vocabulary morphine + ol) + ine; from a former belief that its molecular structure was similar to that of morphine : an oily cyclic secondary… …   Useful english dictionary

  • 110-91-8 — Morpholine Morpholine Général Nom IUPAC tétrahydro 1,4 oxazine No CAS …   Wikipédia en Français