Tametraline

Tametraline

Systematic (IUPAC) name
(1R,4S)-N-methyl-4-phenyl-1,2,3,4-tetrahydronaphthalen-1-amine
Clinical data
Legal status	Legal
Identifiers
CAS Number	52760-47-1
ATC code	none
PubChem	CID 104180
ChemSpider	143316
UNII	440C8K5Y5K
Chemical data
Formula	C17H19N
Molar mass	237.339 g/mol
SMILES CN[C@H](CC1)C(C=CC=C2)=C2[C@H]1C3=CC=CC=C3
InChI InChI=1S/C17H19N/c1-18-17-12-11-14(13-7-3-2-4-8-13)15-9-5-6-10-16(15)17/h2-10,14,17-18H,11-12H2,1H3/t14-,17+/m0/s1 Key:NVXPZMLRGBVYQV-WMLDXEAASA-N
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Tametraline (CP-24,441) is the parent of a series of chemical compounds investigated at Pfizer that eventually led to the development of sertraline (CP-51,974-1).^[1]

Sertraline has been called "3,4-dichloro tametraline". This is correct but it is an oversimplification in the sense that sertraline is the SS isomer whereas tametraline is the 1R,4S stereoisomer.

1R-Methylamino-4S-phenyl-tetralin is a potent inhibitor of norepinephrine uptake in rat brain synaptosomes,^[2] reverses reserpine induced hypothermia in mice, and blocks uptake of [3H] into rat heart.^[3]

Tametraline is a norepinephrine-dopamine reuptake inhibitor.^[4]

Indatraline is an indanamine homolog of tetralin-based tametraline, although in the case of indatraline the product is pm-dichlorinated.

Chemistry

Two routes have been previously described,^[5] one for aryl moieties containing electron withdrawing groups, and one for electron donating groups:

Preparation of Tametraline: U.S. Patent 4,045,488 Reinhard Sarges; Pfizer Inc.

Sarges, R. . (1975). "Synthesis of phenyl-substituted 1-aminotetralines". The Journal of Organic Chemistry 40 (9): 1216–1224. doi:10.1021/jo00897a008.

"As expected, Friedel-Crafts cyclization of the diarylbutyric acid derivatives # to the most reactive ring was observed with little or none of the alternative isomer being detected."

"The KMnO₄ oxidation of the 1-aryl-tetralins # was observed to give 4-hydroxy-4-aryltetralones # instead of the expected tetralone # previously reported.^[5] As a result of this finding, direct oxidation of Grignard reaction product # was attempted and found to be a more efficient route."

See also: U.S. Patent 4,045,488 (and refs therein: doi:10.1021/ja01193a020 doi:10.1021/ja01183a058 doi:10.1021/ja01157a130 doi:10.1021/ja01635a052)

Cis/Trans Ratio

In the case of 3,4-dichloro product, approximately 50:50 cis-/trans- ratio was achieved, according to the reference.^[4]

CAN radical induced dimerization of styrene

"A facile one-pot synthesis of 1-amino-4-aryl-tetralin derivatives by the CAN-induced (see also: CAN) cyclodimerization of various styrenes in acetonitrile and acrylonitrile is described." doi:10.1021/ol0257934

one-pot synthesis of 1-amino-4-aryl-tetralin derivatives by the CAN-induced cyclodimerization of various styrenes in acetonitrile and acrylonitrile

SAR

Certain aromatic substitutients have a potentiating effect (e.g., p-Br), whereas others negate the compound's intrinsic activity.

It is not right to think of the dimethyl analogs as a "prodrug" to the monomethylated drugs (cf. indatraline, "31,345"), but it is correct that that it is a "latentiated" form of the drug. This word is from the salsalate page. This was the reason why sertraline was made only as monomethylated because apparently according to the orders the 1° amine is inactive therefore the drug would have a shorter duration of activity.

Enantiopurified Trans- and Cis- Aminotetraline Derivatives

"31,345" structure:^[6]

Enantiopurified 4-aryl-aminotetralins IC50 (μM)
Stereo	X	Y	NE	DA	5-HT
RS	H	H	0.018	0.15	0.84
SR	H	H	0.37	1.40	14.00
RS	Cl	H	0.019	0.052	0.084
SR	Cl	H	0.46	1.40	3.50
RS	Cl	Cl	0.01	0.044	0.039
SR	Cl	Cl	0.044	0.27	0.47
SS	Cl	Cl	1.20	1.30	0.06
RR	Cl	Cl	0.30	0.32	0.46

Interestingly, (±)-sertraline is not entirely SERT selective until it has been resolved into the SS enantiomer.

In terms of the trans- isomers there is relatively marked separation in the activity between the RS and SR enantiomers. This stands in contrast to what has been observed in the homologous indamine class where both of the trans- enantiomers possessed significant TRI activity at all three of the monoamine transporters.

Racemic Cis- and Trans- Aminotetraline Derivatives

Racemic trans 4-aryl-aminotetralins IC50 (μM) R1 R2 X Y NE DA 5-HT H Me H H 0.04 0.21 1.48 H Me F H 0.03 0.22 0.58 H Me Cl H 0.03 0.10 0.12 H Me Br H 0.03 0.08 0.09 H Me CF3 H 0.69 4.4 0.43 H Me H CF3 0.26 2.60 0.39 H Me OMe H 0.15 0.40 0.38 H Me Cl Cl 0.02 0.06 0.05 Me Me H H 0.14 0.84 0.46 Me Me Cl H 0.13 0.38 0.12 Me Me Cl Cl 0.04 0.17 0.04

Racemic cis 4-aryl-aminotetralins IC50 (μM) R1 R2 X Y 5-HT DA NE H Me H H 3.50 5.10 1.86 H Me F H 1.70 4.70 2.30 H Me Cl H 0.26 1.38 1.41 H Me Br H 0.19 1.60 1.40 H Me CF3 H 0.82 7.80 9.80 H Me H CF3 0.25 2.54 2.55 H Me OMe H 0.70 4.20 3.00 H Me Cl Cl 0.07 0.52 0.72 Me Me H H 1.6 10.0 0.31 Me Me Cl H 0.24 5.60 1.16 Me Me Cl Cl 0.07 2.00 0.40 H H Cl Cl 0.40 1.25 0.25

The primary amines are claimed to completely lack any affinity for the transporters.

See also

Dimefadane[7]	Indriline[8][9]

• CP-24,441 (1R, 4S-N-methyl- 4-phenyl-1,2,3,4-tetrahydro-1-naphthylamine)
• CP-39,332 (N-methyl-4-phenyl-1,2,3,4-tetrahydro-2- naphthylamine)
• Cyproheptadine [4-(5H-dibenz-[a,d]cyclohepten-5-ylidine)-1-methylpiperidine]
• Dasotraline
• Desmethylsertraline
• EXP-561 (1-amino-4-phenylbicyclo[2.2.2]octane)
• JNJ-7925476
• Lometraline
• Nefopam
• Sertraline

Sepracor has tried to patent the trans dichloro analog U.S. Patent 7,105,699.

External links

• http://www.healyprozac.com/Book/Introduction.doc
• http://www.zoominfo.com/people/Koe_Ken_594418650.aspx

During his 40 years at Pfizer, Koe authored more than 100 articles and papers. ... Koe learned to review previous studies and to build on findings that had failed to lead to successful products. In his early work with serotonin, for example, he studied the chemical tametraline, which proved ineffective as an anti-depressant.

Tests showed the chemical functioned more as a stimulant, a use Pfizer was not interested in pursuing. Although his research had failed to yield the desired result, Koe was convinced that the development of a viable anti-depressant was within reach.

References

1. Koe, B. K.; Weissman, A.; Welch, W. M.; Browne, R. G. (1983). "Sertraline, 1S,4S-N-methyl-4-(3,4-dichlorophenyl)-1,2,3,4-tetrahydro-1-naphthylamine, a new uptake inhibitor with selectivity for serotonin". The Journal of Pharmacology and Experimental Therapeutics 226 (3): 686–700. PMID 6310078.
2. Koe, B. K. (1976). "Molecular geometry of inhibitors of the uptake of catecholamines and serotonin in synaptosomal preparations of rat brain". The Journal of Pharmacology and Experimental Therapeutics 199 (3): 649–661. PMID 994022.
3. Sarges, R.; Koe, B. K.; Weissman, A.; Schaefer, J. P. (1974). "Blockade of heart 3H-norepinephrine up-take by 4-phenyl-1-aminotetralines: implications for the active conformation of imipramine-like drugs". The Journal of Pharmacology and Experimental Therapeutics 191 (3): 393–402. PMID 4427286.
4. Welch, W. M.; Kraska, A. R.; Sarges, R.; Koe, B. K. (1984). "Nontricyclic antidepressant agents derived from cis- and trans-1-amino-4-aryltetralins". Journal of Medicinal Chemistry 27 (11): 1508–1515. doi:10.1021/jm00377a021. PMID 6492080.
5. Sarges, R. . (1975). "Synthesis of phenyl-substituted 1-aminotetralines". The Journal of Organic Chemistry 40 (9): 1216–1224. doi:10.1021/jo00897a008.
6. Peng, X. Q.; Xi, Z. X.; Li, X; Spiller, K; Li, J; Chun, L; Wu, K. M.; Froimowitz, M; Gardner, E. L. (2010). "Is slow-onset long-acting monoamine transport blockade to cocaine as methadone is to heroin? Implication for anti-addiction medications". Neuropsychopharmacology 35 (13): 2564–78. doi:10.1038/npp.2010.133. PMC 2978747. PMID 20827272.
7. Barltrop, J. A.; Acheson, R. M.; Philpott, P. G.; MacPhee, K. E.; Hunt, J. S. (1956). "570. Compounds of potential pharmacological interest. Part IV. Aryl and alkyl derivatives of 1-aminoindane". Journal of the Chemical Society (Resumed): 2928. doi:10.1039/JR9560002928.
8. A. Kandel and P, M. Lish, BE 667739  (1966).
9. eidem U.S. Patent 3,360,435