Morpholine
[CAS# 110-91-8]

Identification

• Classification: Organic raw materials >> Heterocyclic compound
• Name: Morpholine
• Synonyms: 1-Oxa-4-azacyclohexane; Tetrahydro-2H-1,4-oxazine
• Molecular Formula: C₄H₉NO
• Molecular Weight: 87.12
• CAS Registry Number: 110-91-8
• EC Number: 203-815-1
• SMILES: C1COCCN1

Properties

• Density: 0.994
• Melting point: -5 °C
• Boiling point: 129 °C
• Refractive index: 1.453-1.455
• Flash point: 38 °C
• Water solubility: MISCIBLE

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS07 Danger
• Risk Statements: H226-H332-H312-H302-H314
• Safety Statements: P210-P233-P234-P240-P241-P242-P243-P260-P261-P264-P264+P265-P270-P271-P273-P280-P301+P317-P301+P330+P331-P302+P352-P302+P361+P354-P303+P361+P353-P304+P340-P305+P354+P338-P316-P317-P321-P330-P362+P364-P363-P370+P378-P390-P391-P403+P235-P405-P406-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Acute toxicity	Acute Tox.	4	H302
Skin corrosion	Skin Corr.	1B	H314
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H312
Serious eye damage	Eye Dam.	1	H318
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	3	H331
Reproductive toxicity	Repr.	2	H361fd
Skin corrosion	Skin Corr.	1A	H314
Reproductive toxicity	Repr.	2	H361
Acute toxicity	Acute Tox.	3	H301
Specific target organ toxicity - single exposure	STOT SE	3	H335
Reproductive toxicity	Repr.	2	H361f
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412

• Transport Information: UN 2054; UN 1760

Discovery and Applications

Morpholine, a versatile heterocyclic compound, was first synthesized in the late 19th century by German chemist Ludwig Knorr during his exploration of heterocyclic chemistry. Its structure consists of a six-membered ring, featuring both nitrogen and oxygen atoms, which grants morpholine unique chemical properties. Morpholine’s chemical formula is C4H9NO, and it possesses both amine and ether functional groups, making it reactive and adaptable in various chemical reactions. Its discovery opened the door to its widespread industrial use, particularly due to its simple preparation from diethylene glycol and ammonia.

One of the most important applications of morpholine is in the chemical industry, where it serves as a precursor and intermediate in the production of numerous chemical compounds. Morpholine is extensively employed in the synthesis of rubber additives, where it is used to accelerate the vulcanization process, a critical step in the production of rubber for tires and other industrial applications. Additionally, it plays a key role in the formulation of corrosion inhibitors, as its basic nature allows it to neutralize acidic environments, thus preventing the degradation of metals in industrial settings, such as in boilers and water treatment plants.

Morpholine is also widely used in the pharmaceutical and agrochemical industries. In drug development, it serves as a building block for various active pharmaceutical ingredients (APIs), providing enhanced solubility, stability, and bioavailability to therapeutic agents. Morpholine derivatives have been explored for their potential in anti-inflammatory, antiviral, and antimalarial drugs. In agriculture, morpholine is incorporated into the synthesis of pesticides and herbicides, contributing to the protection of crops from pests and unwanted vegetation.

In the textile industry, morpholine is used in the production of textile-finishing agents that provide fabrics with smooth, wrinkle-free finishes. Its ability to react with organic acids makes it useful in the formation of textile coatings that improve fabric durability and appearance. Moreover, morpholine derivatives are applied as optical brighteners, enhancing the brightness and color vibrancy of fabrics.

One of the distinctive applications of morpholine is in gas treatment processes, particularly in natural gas and oil refining. It is used as a neutralizing agent in steam systems to prevent corrosion by controlling pH levels. This ensures the integrity and longevity of equipment exposed to high-temperature environments. Morpholine's volatility and solubility in water make it ideal for these systems, as it can evenly distribute throughout the steam and condensate, providing uniform protection against corrosion.

In addition to industrial applications, morpholine is also found in personal care products, where it is used as an emulsifier and stabilizer in cosmetics and shampoos. Its ability to improve the miscibility of different ingredients ensures a homogeneous mixture in creams, lotions, and other personal care formulations.

Morpholine continues to be a valuable chemical in various industries due to its multifunctional nature and ease of production. With ongoing research into its derivatives and applications, morpholine remains an important compound in the development of new materials, pharmaceuticals, and industrial processes.

References

2024. Kinetics and Mechanism for the Reaction of 5-Nitroisatin with Morpholine in Water-Methanol and Water-Acetonitrile Mixed Solvents. Journal of Solution Chemistry.
DOI: 10.1007/s10953-024-01410-7

2013. Chemical Derivatization of Peptide Carboxyl Groups for Highly Efficient Electron Transfer Dissociation. Journal of The American Society for Mass Spectrometry.
DOI: 10.1007/s13361-013-0701-2

2008. Antifungal and Antibacterial Activity of the Newly Synthesized 2‐Xanthone Derivatives. Archiv der Pharmazie.
DOI: 10.1002/ardp.200800089