Trihexyphenidyl

Structural formula
	Mixture of stereoisomers - structural formula without stereochemistry
General
Non-proprietary name	Trihexyphenidyl
other names	( RS ) -1-Cyclohexyl-1-phenyl-3- (1-piperidyl) propan-1-ol; (±) -1-Cyclohexyl-1-phenyl-3- (1-piperidyl) propan-1-ol;
Molecular formula	C 20 H 31 NO
External identifiers / databases
EC number	205-614-4
ECHA InfoCard	100.005.105
PubChem	5572
ChemSpider	5371
DrugBank	DB00376
Wikidata	Q2991856
Drug information
ATC code	N04 AA01
Drug class	Anticholinergics
properties
Molar mass	301.5 g · mol -1
safety instructions
	Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed
GHS labeling of hazardous substances Hydrochloride Caution
H and P phrases	H: 302
	P: no P-phrases
Toxicological data	1660 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Trihexyphenidyl , also known as benzhexol and trihex , is a medicinal substance. It belongs to the group of muscarinic receptor antagonists, similar to atropine . Trihexyphenidyl selectively inhibits the action of acetylcholine on the M ₁ muscarinic receptors in the striatum of the brain. Trihexyphenidyl is an anticholinergic and is used as an anti- parkinson agent. It has been approved under the trade names Artane and Parkopan since 1951 .

The drug consists of a 1: 1 mixture of two enantiomeric chemical compounds from the group of amino alcohols .

effect

Trihexyphenidyl has a relaxing effect on the smooth muscles . This will reduce the tremor in Parkinson's disease.

Extraction and presentation

Trihexyphenidyl can be represented in two ways. In the first step of route 1, 2- (1-piperidino) propiophenone is obtained by aminomethylation of acetophenone with piperidine and paraformaldehyde ( Mannich reaction ). In the second step, this reacts with cyclohexyl magnesium bromide in a Grignard reaction .
For the second synthesis, benzene is reacted with cyclohexanecarboxylic acid chloride as part of a Friedel-Crafts acylation to form cyclohexylphenyl ketone. The ketone then reacts with 2- N -piperidylethylmagnesium chloride in a Grignard reaction to form trihexyphenidyl.

Stereochemistry

Trihexyphenidyl contains a stereocenter and consists of a mixture of two enantiomers. This is a racemate , i.e. a 1: 1 mixture of ( R ) - and ( S ) -form:

Enantiomers of Trihexyphenidyl
( R ) -trihexyphenidyl	( S ) -trihexyphenidyl

Individual evidence

↑ ^a ^b data sheet DL-Trihexyphenidyl hydrochloride from Sigma-Aldrich , accessed on February 19, 2018 ( PDF ).
^ Trihexyphenidyl Oral Solution , accessed February 5, 2018.
↑ JC Frölich, W. Kirch (ed.): Practical medicine therapy . Springer-Verlag, 2003, ISBN 978-3-540-01025-8 , pp. 909–910 ( limited preview in Google Book search).
↑ Rote Liste Service GmbH (Ed.): Rote Liste 2017 - drug directory for Germany (including EU approvals and certain medical devices) . Rote Liste Service GmbH, Frankfurt / Main, 2017, edition 57, ISBN 978-3-946057-10-9 , p. 224.

[Sigma-1] ta sheet DL-Trihexyphenidyl hydrochloride from Sigma-Aldrich , accessed on February 19, 2018 ( PDF ).

[fda-2] Trihexyphenidyl Oral Solution , accessed February 5, 2018.

[3] JC Frölich, W. Kirch (ed.): Practical medicine therapy . Springer-Verlag, 2003, ISBN 978-3-540-01025-8 , pp. 909–910 ( limited preview in Google Book search).

[Rote_Liste-4] Rote Liste Service GmbH (Ed.): Rote Liste 2017 - drug directory for Germany (including EU approvals and certain medical devices) . Rote Liste Service GmbH, Frankfurt / Main, 2017, edition 57, ISBN 978-3-946057-10-9 , p. 224.