Talipexole (B-HT920, Domnin) is a

dopamine agonist A dopamine agonist (DA) is a compound that activates dopamine receptors. There are two families of dopamine receptors, D2-like and D1-like, and they are all G protein-coupled receptors. D1- and D5-receptors belong to the D1-like family and the ...

that is marketed as a treatment for Parkinson's Disease in Japan by

Boehringer Ingelheim C.H. Boehringer Sohn AG & Co. is the parent company of the Boehringer Ingelheim group, which was founded in 1885 by Albert Boehringer in Ingelheim am Rhein, Germany. As of 2018, Boehringer Ingelheim is one of the world's largest pharmaceutical ...

; it was introduced in 1996. As of December 2014 it was not approved for marketing in the US nor in Europe. Talipexole is a D₂

dopamine receptor agonist A dopamine agonist (DA) is a compound that activates dopamine receptors. There are two families of dopamine receptors, D2-like and D1-like, and they are all G protein-coupled receptors. D1- and D5-receptors belong to the D1-like family and the ...

and interacts both pre- and post-synaptic receptors. It also is an α2-adrenergic agonist. The main side effects are drowsiness, dizziness, hallucinations and minor gastrointestinal complaints. In 2008 the Japanese Ministry of Health, Labour, and Welfare mandated that Boehringer add a warning to the label concerning the risk of sudden onset of sleep.Japanese Ministry of Health, Labour and Welfare March 200
Pharmaceuticals and Medical Devices Safety Information No. 245
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Synthesis

The N-alkylation of azepan-4-one 05416-56-6(1) with

allyl bromide Allyl bromide (3-bromopropene) is an organic halide. It is an alkylating agent used in synthesis of polymers, pharmaceuticals, synthetic perfumes and other organic compounds. Physically, allyl bromide is a colorless liquid with an irritating and p ...

in the presence of potassium carbonate gives 1-allyl-azepan-4-one (2). This is halogenated with molecular bromine in acetic acid to give 1-allyl-5-bromohexahydro-4-azepinone (3). The last step involves cyclization with

thiourea Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), except that the oxygen atom is replaced by a sulfur atom (as implied by the ''thio-'' prefix); however, the properties of urea ...

(4) in refluxing ethanol, completing the synthesis of talipexole (5).

References

Alpha-1 blockers Alpha-2 adrenergic receptor agonists Allyl compounds Azepanes D2-receptor agonists Dopamine agonists Thiazoles {{nervous-system-drug-stub

Synthesis

See also

References