O-689

Synonym(s):2-Methyl-2′-fluoro AEA;Fluoromethanandamide;O-689

CAS NO.：166100-39-6
Empirical Formula: C23H38FNO
Molecular Weight: 363.55
MDL number: MFCD01862615
EINECS: 200-578-6
SAFETY DATA SHEET (SDS)
Update Date: 2026-05-28 05:46:53

What is O-689?

Description

(±)-2-Methyl arachidonoyl-2''-fluoroethylamide (2-Methyl-2''-fluoro AEA) is an analog of anandamide (AEA) in which the alcohol of the ethanolamide group has been removed and replaced with a fluorine atom. This substitution confers considerably increased binding affinity for the CB₁ receptor (K_i = 5.7 nM in rat brain). It also confers additional selectivity, in that binding to CB₂ is decreased relative to AEA. However, the in vivo activity of 2-fluoro AEA is enhanced much less than the binding affinity, because the analog remains a good substrate for FAAH and is rapidly hydrolyzed by this enzyme. 2-Methyl-2''-fluoro AEA is further modified by the addition of an α-methyl group at the C-2 position of arachidonic acid. This substitution confers enhanced metabolic stability. 2-Methyl-2''-fluoro AEA can fully substitute for Δ⁹-THC in animal self-administration tests, whereas AEA and 2-fluoro AEA cannot.

Properties of O-689

Boiling point:	503.6±50.0 °C(Predicted)
Density	0.921±0.06 g/cm3(Predicted)
Flash point:	14 °C
storage temp.	−20°C
solubility	DMF: >10 mg/ml; DMSO: >30 mg/ml; Ethanol: >100 mg/ml; Ethanol:PBS (1:2): 8.5 mg/ml; PBS (pH 7.2): <100 μg/ml
form	ethanol solution
pka	14.98±0.46(Predicted)

Safety information for O-689

Signal word	Danger
Pictogram(s)	Flame Flammables GHS02 Exclamation Mark Irritant GHS07
GHS Hazard Statements	H225:Flammable liquids H319:Serious eye damage/eye irritation
Precautionary Statement Codes	P210:Keep away from heat/sparks/open flames/hot surfaces. — No smoking. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.