Morpholine

Morpholine
Names
	Preferred IUPAC name Morpholine
	Other names Diethylenimide oxide; 1,4-Oxazinane; Tetrahydro-1,4-oxazine; Diethylene imidoxide; Diethylene oximide; Tetrahydro-p-oxazine
Identifiers
CAS Number	110-91-8 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	102549
ChEBI	CHEBI:34856 ;
ChEMBL	ChEMBL276518 ;
ChemSpider	13837537 ;
ECHA InfoCard	100.003.469
EC Number	203-815-1;
Gmelin Reference	1803
KEGG	C14452 ;
PubChem CID	8083;
RTECS number	QD6475000;
UNII	8B2ZCK305O ;
UN number	2054
CompTox Dashboard (EPA)	DTXSID2025688;
	InChI InChI=1S/C4H9NO/c1-3-6-4-2-5-1/h5H,1-4H2 Key: YNAVUWVOSKDBBP-UHFFFAOYSA-N ; InChI=1/C4H9NO/c1-3-6-4-2-5-1/h5H,1-4H2 Key: YNAVUWVOSKDBBP-UHFFFAOYAU;
	SMILES C1CNCCO1;
Properties
Chemical formula	C4H9NO
Molar mass	87.122 g·mol−1
Appearance	Colorless liquid
Odor	Weak ammonia-like or fish-like
Density	1.007 g/cm3
Melting point	−5 °C (23 °F; 268 K)
Boiling point	129 °C (264 °F; 402 K)
Solubility in water	miscible
Vapor pressure	6 mmHg (20 °C)
Acidity (pKa)	8.36 (of conjugate acid)
Magnetic susceptibility (χ)	−55.0·10−6 cm3/mol
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Flammable, Corrosive
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H226, H302, H312, H314, H332
Precautionary statements	P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P321, P322, P330, P363, P370+P378, P403+P235, P405, P501
NFPA 704 (fire diamond)	3 3 0
Flash point	31 °C (88 °F; 304 K)
Autoignition; temperature	275 °C (527 °F; 548 K)
Explosive limits	1.4%–11.2%
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	1220 mg/kg (mammal, oral); 525 mg/kg (mouse, oral); 1050 mg/kg (rat, oral)
LC50 (median concentration)	365 ppm (mouse, 2 hr)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 20 ppm (70 mg/m3) [skin]
REL (Recommended)	TWA 20 ppm (70 mg/m3) ST 30 ppm (105 mg/m3) [skin]
IDLH (Immediate danger)	1400 ppm
Safety data sheet (SDS)	hazard.com
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Morpholine is an organic chemical compound having the chemical formula O(C H₂CH₂)₂NH. This heterocycle features both amine and ether functional groups. Because of the amine, morpholine is a base; its conjugate acid is called morpholinium. For example, treating morpholine with hydrochloric acid generates the salt morpholinium chloride. It is a colorless liquid with a weak, ammonia- or fish-like odor. The naming of morpholine is attributed to Ludwig Knorr, who incorrectly believed it to be part of the structure of morphine.