Title: Ecgonine
CAS Registry Number: 481-37-8
CAS Name: [1R-(exo,exo)]-3-Hydroxy-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylic acid
Additional Names: 3b-hydroxy-1aH,5aH-tropane-2b-carboxylic acid
Molecular Formula: C9H15NO3
Molecular Weight: 185.22
Percent Composition: C 58.36%, H 8.16%, N 7.56%, O 25.91%
Literature References: The principal part of the cocaine molecule; naturally occurring as the l-form. Obtained by hydrolysis of cocaine: Willstätter et al., Ann. 434, 111 (1923); Bell, Archer, J. Am. Chem. Soc. 82, 4642 (1960). From coca leaves: de Jong, Rec. Trav. Chim. 59, 687 (1940). Structure: Gadamer, John, Arch. Pharm. 259, 227 (1921). Stereochemistry: Fodor, Nature 170, 278 (1952); Fodor, Kovács, J. Chem. Soc. 1953, 724. Synthesis: Willstätter, Bommer, Ann. 422, 15 (1920). Review: Stoll, Jucker, Angew. Chem. 66, 376 (1954).
Derivative Type: l-Form monohydrate
CAS Registry Number: 5796-30-5
Properties: Triboluminescent, monoclinic prisms from alc, mp 198° (anhydr, dec 205°). [a]D15 -45° (c = 5). Neutral to litmus. pKa 11.11; pKb 11.22. One gram dissolves in 5 ml water, 67 ml alc, 20 ml methanol, 75 ml ethyl acetate. Sparingly sol in acetone, ether, benzene, chloroform, petr ether.
Melting point: mp 198° (anhydr, dec 205°)
pKa: pKa 11.11; pKb 11.22
Optical Rotation: [a]D15 -45° (c = 5)
Derivative Type: Hydrochloride
CAS Registry Number: 5796-31-6
Molecular Formula: C9H15NO3.HCl
Molecular Weight: 221.68
Percent Composition: C 48.76%, H 7.27%, N 6.32%, O 21.65%, Cl 15.99%
Properties: Triclinic plates from water, mp 246°. [a]D15 -59° (c = 10). Sol in water; slightly in alc.
Melting point: mp 246°
Optical Rotation: [a]D15 -59° (c = 10)
Derivative Type: dl-Form trihydrate
Properties: Plates from 90% alcohol, mp 93-118° (anhydr dec 212°).
Melting point: mp 93-118° (anhydr dec 212°)
NOTE: This is a controlled substance: 21 CFR, 1308.12.
Therap-Cat: Anesthetic (topical).
Keywords: Anesthetic (Local).
Echinenone Echinochrome A Echinomycin Echinopsine Echinuline

Semi-skeletal formula of ecgonine
Ball-and-stick model of the ecgonine molecule
CAS number 481-37-8 YesY
PubChem 91460
ChemSpider 82586 N
DrugBank DB01525
Jmol-3D images Image 1
Molecular formula C9H15NO3
Molar mass 185.2203 g·mol−1
Density 1.293 ± 0.06 g·cm−3
Melting point 198–199 °C
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Ecgonine (tropane derivative) is a tropane alkaloid found naturally in coca leaves. It has a close structural relation to cocaine: it is both a metabolite and a precursor, and as such, it is a controlled substance, as are all known substances which can be used as precursors to ecgonine itself.

Structurally, ecgonine is a cycloheptane derivative with a nitrogen bridge. It is obtained by hydrolysis of cocaine with acids or alkalis, and crystallizes with one molecule of water, the crystals melting at 198–199 °C. It is levorotary, and on warming with alkalis gives iso-ecgonine, which is dextrorotary.

It is a tertiary base, and has the properties of an acid and an alcohol. It is the carboxylic acid corresponding to tropine, for it yields the same products on oxidation, and by treatment with phosphorus pentachloride is converted into anhydroecgonine, C9H13NO2, which, when heated to 280 °C with hydrochloric acid, eliminates carbon dioxide and yields tropidine, C8H13N.