Methylecgonidine

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Methylecgonidine
Methylecgonidine.png
Names
IUPAC name
Methyl trop-2-ene-2β-carboxylate
Systematic IUPAC name
Methyl (1R,5S)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene-2-carboxylate
Other names
Anhydromethylecgonine
Anhydroecgonine methyl ester
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.164.719 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/C10H15NO2/c1-11-7-3-5-8(10(12)13-2)9(11)6-4-7/h5,7,9H,3-4,6H2,1-2H3/t7-,9+/m0/s1 Yes check.svgY
    Key: MPSNEAHFGOEKBI-IONNQARKSA-N Yes check.svgY
  • InChI=1/C10H15NO2/c1-11-7-3-5-8(10(12)13-2)9(11)6-4-7/h5,7,9H,3-4,6H2,1-2H3/t7-,9+/m0/s1
    Key: MPSNEAHFGOEKBI-IONNQARKBC
  • CN2[C@@H]/1CC[C@@H]2C\C=C\1C(=O)OC
Properties
C10H15NO2
Molar mass 181.235 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Methylecgonidine (anhydromethylecgonine; anhydroecgonine methyl ester; AEME) is a chemical intermediate derived from ecgonine or cocaine.

Contents

Methylecgonidine is a pyrolysis product formed when crack cocaine is smoked, making this substance a useful biomarker to specifically test for use of crack cocaine, as opposed to powder cocaine which does not form methylecgonidine as a metabolite. [1] Methylecgonidine has a relatively short half-life of 18–21 minutes, after which it is metabolised to ecgonidine, meaning that the relative concentrations of the two compounds can be used to estimate how recently crack cocaine has been smoked. Methylecgonidine has been shown to be specifically more harmful to the body than other byproducts of cocaine; for example to the heart, [2] lungs [3] & liver. [4] The toxicity is due to a partial agonist effect at M1 and M3 muscarinic receptors, leading to DNA fragmentation and neuronal death by apoptosis. [5]

AEME is also used in scientific research for the manufacture of phenyltropane analogues such as troparil, dichloropane, iometopane, and CFT. Methylecgonidine could also theoretically be used to produce cocaine and so may be a controlled substance in some countries.

Synthesis

Methylecgonidine synthesis from cocaine Methylecgonidine synthesis 1.svg
Methylecgonidine synthesis from cocaine

Methylecgonidine can be synthesized non pyrolytically from cocaine via hydrolysis/dehydration [6] followed by esterification with methanol. [7] [8]

Methylecgonidine synthesis by Kline Methylecgonidine synthesis 2.svg
Methylecgonidine synthesis by Kline

The scheme by Kline [9] is based on the reaction of 2,4,6-cycloheptatriene-7-carboxylic acid with methylamine. This is a modified version of U.S. Patent 2,783,235 by Grundmann and Ottmann. In the accompanying patent U.S. Patent 2,783,236 these same authors react their methylecgonidine with two equivalents of PhLi to form a tertiary alcohol by "hard" addition to the ester and not "soft" Michael addition. However, the product is only one tenth the potency of atropine. The methyl 2,4,6-cycloheptatriene-1-carboxylate can be made synthetically. [10] [11]

Methylecgonidine synthesis by Davies. Enantioselective Methylecgonidine synthesis 3.svg
Methylecgonidine synthesis by Davies. Enantioselective

Davies et al. synthesized (R/S)-methylecgonidine by a tandem cyclopropanation/Cope rearrangement. [13] [14] Thus, reaction of methyldiazobutenoate (2) with 5 equiv of N-((2-(TMS)ethoxy)carbonyl)pyrrole (1) in the presence of rhodium(II) hexanoate/hexane gave the [3.2.1]-azabicyclic system (R/S)-8 in 62% yield. The unsubstituted double bond was selectively reduced using Wilkinson catalyst to provide N-protected anhydroecgonine methyl ester ((R/S)-4). Following deprotection of N8 nitrogen with TBAF and reductive methylation with formaldehyde and sodium cyanoborohydride, (R/S)-5 was obtained in overall good yield.

See also

Related Research Articles

<span class="mw-page-title-main">Cocaethylene</span> Chemical compound

Cocaethylene (ethylbenzoylecgonine) is the ethyl ester of benzoylecgonine. It is structurally similar to cocaine, which is the methyl ester of benzoylecgonine. Cocaethylene is formed by the liver when cocaine and ethanol coexist in the blood. In 1885, cocaethylene was first synthesized, and in 1979, cocaethylene's side effects were discovered.

The Simmons–Smith reaction is an organic cheletropic reaction involving an organozinc carbenoid that reacts with an alkene to form a cyclopropane. It is named after Howard Ensign Simmons, Jr. and Ronald D. Smith. It uses a methylene free radical intermediate that is delivered to both carbons of the alkene simultaneously, therefore the configuration of the double bond is preserved in the product and the reaction is stereospecific.

<span class="mw-page-title-main">WIN-35428</span> Chemical compound

(–)-2-β-Carbomethoxy-3-β-(4-fluorophenyl)tropane is a stimulant drug used in scientific research. CFT is a phenyltropane based dopamine reuptake inhibitor and is structurally derived from cocaine. It is around 3-10x more potent than cocaine and lasts around 7 times longer based on animal studies. While the naphthalenedisulfonate salt is the most commonly used form in scientific research due to its high solubility in water, the free base and hydrochloride salts are known compounds and can also be produced. The tartrate is another salt form that is reported.

<span class="mw-page-title-main">Cyclopropanation</span> Chemical process which generates cyclopropane rings

In organic chemistry, cyclopropanation refers to any chemical process which generates cyclopropane rings. It is an important process in modern chemistry as many useful compounds bear this motif; for example pyrethroid insecticides and a number of quinolone antibiotics. However, the high ring strain present in cyclopropanes makes them challenging to produce and generally requires the use of highly reactive species, such as carbenes, ylids and carbanions. Many of the reactions proceed in a cheletropic manner.

The Kulinkovich reaction describes the organic synthesis of substituted cyclopropanols through reaction of esters with dialkyl­dialkoxy­titanium reagents, which are generated in situ from Grignard reagents containing a hydrogen in beta-position and titanium(IV) alkoxides such as titanium isopropoxide. This reaction was first reported by Oleg Kulinkovich and coworkers in 1989.

<span class="mw-page-title-main">Rhodium(II) acetate</span> Chemical compound

Rhodium(II) acetate is the coordination compound with the formula Rh2(AcO)4, where AcO is the acetate ion (CH
3
CO
2
). This dark green powder is slightly soluble in polar solvents, including water. It is used as a catalyst for cyclopropanation of alkenes. It is a widely studied example of a transition metal carboxylate complex.

<span class="mw-page-title-main">Troparil</span> Chemical compound

Troparil is a stimulant drug used in scientific research. Troparil is a phenyltropane-based dopamine reuptake inhibitor (DRI) that is derived from methylecgonidine. Troparil is a few times more potent than cocaine as a dopamine reuptake inhibitor, but is less potent as a serotonin reuptake inhibitor, and has a duration spanning a few times longer, since the phenyl ring is directly connected to the tropane ring through a non-hydrolyzable carbon-carbon bond. The lack of an ester linkage removes the local anesthetic action from the drug, so troparil is a pure stimulant. This change in activity also makes troparil slightly less cardiotoxic than cocaine. The most commonly used form of troparil is the tartrate salt, but the hydrochloride and naphthalenedisulfonate salts are also available, as well as the free base.

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<span class="mw-page-title-main">Dichloropane</span> Chemical compound

Dichloropane ((−)-2β-Carbomethoxy-3β-(3,4-dichlorophenyl)tropane, RTI-111, O-401) is a stimulant of the phenyltropane class that acts as a serotonin–norepinephrine–dopamine reuptake inhibitor (SNDRI) with IC50 values of 3.13, 0.79 and 18 nM, respectively. In animal studies, dichloropane had a slower onset and longer duration of action compared to cocaine.

<span class="mw-page-title-main">RTI-126</span> Pharmaceutical drug

RTI-126 is a phenyltropane derivative which acts as a potent monoamine reuptake inhibitor and stimulant drug, and has been sold as a designer drug. It is around 5 times more potent than cocaine at inhibiting monoamine reuptake in vitro, but is relatively unselective. It binds to all three monoamine transporters, although still with some selectivity for the dopamine transporter. RTI-126 has a fast onset of effects and short duration of action, and its pharmacological profile in animals is among the closest to cocaine itself out of all the drugs in the RTI series. Its main application in scientific research has been in studies investigating the influence of pharmacokinetics on the abuse potential of stimulant drugs, with its rapid entry into the brain thought to be a key factor in producing its high propensity for development of dependence in animals.

<span class="mw-page-title-main">Biosynthesis of cocaine</span>

The biosynthesis of cocaine has long attracted the attention of biochemists and organic chemists. This interest is partly motivated by the strong physiological effects of cocaine, but a further incentive was the unusual bicyclic structure of the molecule. The biosynthesis can be viewed as occurring in two phases, one phase leading to the N-methylpyrrolinium ring, which is preserved in the final product. The second phase incorporates a C4 unit with formation of the bicyclic tropane core.

<span class="mw-page-title-main">RTI-31</span> Chemical compound

(–)-2β-Carbomethoxy-3β-(4'-chlorophenyl)tropane (RTI-4229-31) is a synthetic analog of cocaine that acts as a stimulant. Semi-synthesis of this compound is dependent upon the availability of cocaine starting material. According to the article, RTI-31 is 64 x the strength of cocaine in terms of its potency to elicit self-administration in monkeys. WIN 35428 was 6 x weaker than RTI-31, whereas RTI-51 was 2.6 x weaker than RTI-31.

Reductions with hydrosilanes are methods used for hydrogenation and hydrogenolysis of organic compounds. The approach is a subset of ionic hydrogenation. In this particular method, the substrate is treated with a hydrosilane and auxiliary reagent, often a strong acid, resulting in formal transfer of hydride from silicon to carbon. This style of reduction with hydrosilanes enjoys diverse if specialized applications.

Metal-catalyzed cyclopropanations are chemical reactions that result in the formation of a cyclopropane ring from a metal carbenoid species and an alkene. In the Simmons–Smith reaction the metal involved is zinc. Metal carbenoid species can be generated through the reaction of a diazo compound with a transition metal). The intramolecular variant of this reaction was first reported in 1961. Rhodium carboxylate complexes, such as dirhodium tetraacetate, are common catalysts. Enantioselective cyclopropanations have been developed.

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Methylecgonone reductase (EC 1.1.1.334, MecgoR (gene name)) is an enzyme with systematic name ecgonine methyl ester:NADP+ oxidoreductase. This enzyme catalyses the following chemical reaction

The Chan–Lam coupling reaction – also known as the Chan–Evans–Lam coupling is a cross-coupling reaction between an aryl boronic acid and an alcohol or an amine to form the corresponding secondary aryl amines or aryl ethers, respectively. The Chan–Lam coupling is catalyzed by copper complexes. It can be conducted in air at room temperature. The more popular Buchwald–Hartwig coupling relies on the use of palladium.

<span class="mw-page-title-main">Methylecgonine</span> Chemical compound

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References

  1. Scheidweiler KB, Plessinger MA, Shojaie J, Wood RW, Kwong TC (December 2003). "Pharmacokinetics and pharmacodynamics of methylecgonidine, a crack cocaine pyrolyzate". The Journal of Pharmacology and Experimental Therapeutics. 307 (3): 1179–87. doi:10.1124/jpet.103.055434. PMID   14561847. S2CID   15619796.
  2. Pharmacokinetics and Pharmacodynamics of Methylecgonidine, a Crack Cocaine Pyrolyzate - Scheidweiler et al. 307 (3): 1179 Figure IG6 - Journal of Pharmacology and Experimental Therapeutics
  3. Yang Y, Ke Q, Cai J, Xiao YF, Morgan JP (January 2001). "Evidence for cocaine and methylecgonidine stimulation of M(2) muscarinic receptors in cultured human embryonic lung cells". British Journal of Pharmacology. 132 (2): 451–60. doi:10.1038/sj.bjp.0703819. PMC   1572570 . PMID   11159694.
  4. Fandiño AS, Toennes SW, Kauert GF (December 2002). "Studies on hydrolytic and oxidative metabolic pathways of anhydroecgonine methyl ester (methylecgonidine) using microsomal preparations from rat organs". Chemical Research in Toxicology. 15 (12): 1543–8. doi:10.1021/tx0255828. PMID   12482236.
  5. Garcia RC, Dati LM, Torres LH, da Silva MA, Udo MS, Abdalla FM, et al. (December 2015). "M1 and M3 muscarinic receptors may play a role in the neurotoxicity of anhydroecgonine methyl ester, a cocaine pyrolysis product". Scientific Reports. 5: 17555. Bibcode:2015NatSR...517555G. doi:10.1038/srep17555. PMC   4667193 . PMID   26626425.
  6. Basmadjian GP, Singh S, Sastrodjojo B, Smith BT, Avor KS, Chang F, et al. (November 1995). "Generation of polyclonal catalytic antibodies against cocaine using transition state analogs of cocaine conjugated to diphtheria toxoid". Chemical & Pharmaceutical Bulletin. 43 (11): 1902–11. doi:10.1021/ja01502a049. PMID   8575031.
  7. De Jong AW (1937). "Some properties of the ecgonines and their esters II. The structural formulae of the ecgonines and ecgonidine". Recueil des Travaux Chimiques des Pays-Bas. 56 (2): 186–97, 198–201. doi:10.1002/recl.19370560215.
  8. Matchett JR, Levine J (1941). "Isolation of Ecgonidine Methyl Ester from Coca Seeds 1". J. Am. Chem. Soc. 63 (9): 2444–2446. doi:10.1021/ja01854a038.
  9. Kline RH, Wright J, Fox KM, Eldefrawi ME (July 1990). "Synthesis of 3-arylecgonine analogues as inhibitors of cocaine binding and dopamine uptake". Journal of Medicinal Chemistry. 33 (7): 2024–7. doi:10.1021/jm00169a036. PMID   2362282.
  10. "Methyl 2,4,6-cycloheptatriene-1-carboxylate - C9H10O2, density, melting point, boiling point, structural formula, synthesis".
  11. Anciaux AJ, Demonceau A, Noels AF, Hubert AJ, Warin R, Teyssie P (1981). "Transition-metal-catalyzed reactions of diazo compounds. 2. Addition to aromatic molecules: Catalysis of Buchner's synthesis of cycloheptatrienes". The Journal of Organic Chemistry. 46 (5): 873–876. doi:10.1021/jo00318a010. hdl:2268/237697.
  12. Davies HM, Huby NJ (1992). "Enantioselective synthesis of tropanes by reaction of rhodium-stabilized vinylcarbenoids with pyrroles". Tetrahedron Letters. 33 (46): 6935–6938. doi:10.1016/S0040-4039(00)60899-7. ISSN   0040-4039.
  13. Davies, H. M. L.; Saikali, E.; Young, W. B. (1991). "Synthesis of (.+-.)-ferruginine and (.+-.)-anhydroecgonine methyl-ester by a tandem cyclopropanation/Cope rearrangement". J. Org. Chem. 56 (19): 5696–5700. doi:10.1021/jo00019a044.
  14. Davies HM, Young WB, Smith HD (January 1989). "Novel entry to the tropane system by reaction of rhodium (II) acetate stabilized vinylcarbenoids with pyrroles". Tetrahedron Letters. 30 (35): 4653–6. doi:10.1016/S0040-4039(01)80766-8.