Alkanolamine

Last updated

In organic chemistry, alkanolamines (amino alcohols) are organic compounds that contain both hydroxyl (−OH) and amino (−NH2, −NHR, and −NR2) functional groups on an alkane backbone. Alkanolamine's bifunctionality and physicochemical characteristics lead to its use in many applications, such as textiles, cosmetics, agricultural chemical intermediates, drugs, and metal working fluids. [1] [2] Alkanolamines are present in many approved drugs and thousands of natural products. [3] Two amino acids are alkanolamines, formally speaking: serine and hydroxyproline.

Contents

Alkanolamines usually have high-solubility in water due to the hydrogen bonding ability of both the hydroxyl group and the amino group. [4] Alkanoamines have also shown a broad toxicity for a variety of organisms, including parasites, insect larvae and eggs, and microbes. Studies have also shown that the antimicrobial effect of alkanolamines increases in higher pH's. [5] Most alkanolamines are colorless. [6]

1-Aminoalcohols

1-Aminoalcohols are better known as hemiaminals. Methanolamine is the simplest member. 1-Aminoalcohols tend to be labile, readily converting to more highly condensed derivatives or hydrolyzing to the amine and carbonyl.

2-Aminoalcohols

Routes

2-Aminoalcohols are often generated by the reaction of amines with epoxides:

C2H4O + R−NH2 → RNHC2H4OH

Hydrogenation or reduction of amino acids gives a large family of chiral 2-aminoalcohols:

RCH(NH2)CO2H + 2 H2 → RCH(NH2)CH2OH + H2O

Examples include prolinol (from proline), valinol (from valine), tyrosinol (from tyrosine). Some 2-aminoalcohols are produced by the Sharpless asymmetric amino hydroxylation. [7]

Uses and examples

Simple alkanolamines are used as solvents, synthetic intermediates, and high-boiling bases. [6]

2-Aminoalcohols have been used as synthetic building blocks and chiral auxiliaries.Amino ethanols have been proven to be vital precursors for chiral morpholines and piperazines. [3] [8] Key members: ethanolamine, dimethylethanolamine, N-methylethanolamine, Aminomethyl propanol. Two popular drugs, often called alkanolamine beta blockers, are members of this structural class: propranolol, pindolol. [9] [10] [11] 2-Aminoalcohols can also be found in the direct action subgroup of adrenergic drugs such as epinephrine, isoproterenol, phenylephrine and isoetarine. [12]

Other medicinally useful derivative of ethanolamine: Isoetarine, veratridine, veratrine, epinephrine (adrenaline), norepinephrine (noradrenaline), atropine.

1,3- to 1,7-amino alcohols

Two examples of longer aminoalcohols include Heptaminol, a cardiac stimulant, and propanolamines.

1,3-Aminoalcohols are present in several bioactive molecules, such as Sedinone, Dumetorine, and Hygroline. [13] 1,3-Aminoalcohols have be synthesize through a couple methods. Similar to 2-aminoalcohols, 1,3 aminoalcohols can be formed through ring openings, such as an azo-ring opening and addition. [13] 1,3-aminoalcohols can also be synthesized through an azo-aldol condensation or an intermolecular C-H activation. [13]

1,4 and 1,5-aminoalcohols have been synthesized through the reduction of cyclic amides. [14] Catalyzed alkylation of primary amines with 1,4-butanediol is another synthetic route for 1,4-aminoalcohols. [14] Larger amino alcohol (1,5 - and up) synthesis is comparatively underdeveloped. Electrochemical ring-openings can produce 1,3 to 1,7-aminoalcohols. [15]

References

  1. Davis, John W.; Carpenter, Constance L. (1997), Ware, George W. (ed.), "Environmental Assessment of the Alkanolamines" , Reviews of Environmental Contamination and Toxicology, 149, New York, NY: Springer New York: 87–137, doi:10.1007/978-1-4612-2272-9_2, ISBN   978-1-4612-7482-7, PMID   8956559 , retrieved 2025-03-19
  2. Laskar, Ranjini; Dutta, Subhabrata; Spies, Jan C.; Mukherjee, Poulami; Rentería-Gómez, Ángel; Thielemann, Rebecca E.; Daniliuc, Constantin G.; Gutierrez, Osvaldo; Glorius, Frank (2024-04-17). "γ-Amino Alcohols via Energy Transfer Enabled Brook Rearrangement". Journal of the American Chemical Society. 146 (15): 10899–10907. Bibcode:2024JAChS.14610899L. doi:10.1021/jacs.4c01667. ISSN   0002-7863. PMC   11027157 . PMID   38569596.
  3. 1 2 Sun, Jiawei; Wang, Shuanghu; Harper, Kaid C.; Kawamata, Yu; Baran, Phil S. (January 2025). "Stereoselective amino alcohol synthesis via chemoselective electrocatalytic radical cross-couplings" . Nature Chemistry. 17 (1): 44–53. doi:10.1038/s41557-024-01695-7. ISSN   1755-4349.
  4. "Amino Alcohols - Alfa Chemistry". www.alfa-chemistry.com. Retrieved 2025-03-28.
  5. Sandin, M; Allenmark, S; Edebo, L (March 1990). "Selective toxicity of alkanolamines". Antimicrobial Agents and Chemotherapy. 34 (3): 491–493. doi:10.1128/AAC.34.3.491. ISSN   0066-4804. PMC   171625 . PMID   2334165.
  6. 1 2 Martin Ernst; Johann-Peter Melder; Franz Ingo Berger; Christian Koch (2022). "Ethanolamines and Propanolamines". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a10_001.pub2. ISBN   978-3-527-30673-2.
  7. Herranz, E.; Sharpless, K. B. (1983). "Osmium-Catalyzed Vicinal Oxyamination of Olefins by Chloramine-T: cis-2-(p-Toluenesulfonamido)cyclohexanol and 2-Methyl-3-(p-Toluenesulfonamido)-2-Pentanol". Org. Synth. 61: 85. doi:10.15227/orgsyn.061.0085.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  8. Ager, David J.; Prakash, Indra; Schaad, David R. (1996-01-01). "1,2-Amino Alcohols and Their Heterocyclic Derivatives as Chiral Auxiliaries in Asymmetric Synthesis" . Chemical Reviews. 96 (2): 835–876. doi:10.1021/cr9500038. ISSN   0009-2665.
  9. "Propranolol Monograph for Professionals". Drugs.com. Retrieved 2025-03-28.
  10. "Pindolol Uses, Side Effects & Warnings". Drugs.com. Retrieved 2025-03-28.
  11. Wong, Gavin W. K.; Boyda, Heidi N.; Wright, James M. (2014-11-27). "Blood pressure lowering efficacy of partial agonist beta blocker monotherapy for primary hypertension". The Cochrane Database of Systematic Reviews. 2014 (11): CD007450. doi:10.1002/14651858.CD007450.pub2. ISSN   1469-493X. PMC   6486122 . PMID   25427719.{{cite journal}}: CS1 maint: article number as page number (link)
  12. Vardanyan, R. S.; Hruby, V. J. (2006-01-01), Vardanyan, R. S.; Hruby, V. J. (eds.), "11 - Adrenergic (Sympathomimetic) Drugs", Synthesis of Essential Drugs, Amsterdam: Elsevier, pp. 143–159, ISBN   978-0-444-52166-8, retrieved 2025-03-28
  13. 1 2 3 Wang, Wei; Hu, Yi; Lin, Ruiqi; Wu, Heng; Tong, Qi; Wang, Liansheng; Xiao, Zufeng; Zhu, Lei (2020). "Progress on the Synthesis of 1,3-Amino Alcohol". Chinese Journal of Organic Chemistry. 40 (5): 1129. doi:10.6023/cjoc201911011. ISSN   0253-2786.
  14. 1 2 Xiao, Zhen; Li, Juanjuan; Yue, Qiang; Zhang, Qian; Li, Dong (2018). "An efficient and atom-economical route to N -aryl amino alcohols from primary amines". RSC Advances. 8 (60): 34304–34308. doi:10.1039/C8RA07355D. ISSN   2046-2069. PMC   9086943 . PMID   35548644.
  15. Fang, Xinyue; Hu, Xinwei; Li, Quan-Xin; Ni, Shao-Fei; Ruan, Zhixiong (2025). "Paired Electro-Synthesis of Remote Amino Alcohols with/in H2O". Angewandte Chemie International Edition. 64 (6): e202418277. doi:10.1002/anie.202418277. ISSN   1521-3773.{{cite journal}}: CS1 maint: article number as page number (link)