Meclizine

• Meclizine
• (RS ) -1 - [(4 -chlorophenyl)- phenylmethyl] -4 - [ ( 3-methylphenyl) methyl] piperazine ( IUPAC)

• C25H27ClN2 [( RS)- meclozine ]
• C25H27ClN2 · 2HCl [( RS)- meclozine · dihydrochloride ]
• C25H27ClN2 · 2HCl · 2H2O [( RS)- meclizine dihydrochloride · · monohydrate ]

• 569-65-3 [( RS)- meclozine ]
• 1104-22-9 [( RS)- meclozine · dihydrochloride ]
• 31884-77-2 [( RS)- meclizine dihydrochloride · · monohydrate ]

R06AE05

Antihistamines

• 390.95 g · mol -1 [( RS)- meclozine ]
• 463.88 g · mol -1 [( RS)- meclozine · dihydrochloride ]
• 481.90 g · mol -1 [( RS)- meclizine dihydrochloride · · monohydrate ]

206-216 ° C with decomposition (racemate dihydrochloride )

230 ° C.

• 625 mg · kg -1 ( LD50, mouse, i.m. )
• 1650 mg · kg -1 ( LD50, mouse, oral)
• 1750 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Meclozine is a drug from the group of systemic H1 antihistamines. It is effective against nausea and vomiting, and experience has shown that even during pregnancy safe to use. Since 2007, however, it is in Germany no longer commercially available (former name: Postadoxin N ®).

Synthesis

The synthesis of meclozine starts from (4 -chloro-phenyl ) - phenylmethanol which is first reacted according to halogenation using thionyl chloride, and reaction with a 4- acetylpiperazine Chlorphenylphenylpiperazinylmethan intermediate. After acidic cleavage of the acetyl N-alkylation on the piperazine ring with 3- methylbenzyl chloride is carried to the racemic target molecule.

Alternatively, the final step of the synthesis may be performed as a reductive N- alkylation of the piperazine ring with 3- methylbenzaldehyde.

In the synthesis of the racemate obtained. For pharmaceutical applications, the compound is converted into the dihydrochloride.

Clinical information

Meclizine is used to treat nausea and vomiting, particularly motion sickness and vomiting during pregnancy.

The safety for use during pregnancy has been well documented, it even applies to vomiting during pregnancy as a means of choice. As an alternative, among others, doxylamine comes into question.

Pharmacological properties

Meclozine acts by competitive inhibition of histamine H1-receptors. Since it antihistaminic first generation crosses the blood -brain barrier, it is not only anti-emetic, but also makes tired.

Stereoisomerism

Meclozine contains a stereogenic center is chiral. The drug is a racemate [ 1:1 mixture of (R) -1 - [(4 -chlorophenyl)- phenylmethyl] -4 - [ ( 3-methylphenyl) methyl] piperazine and (S) -1 - [(4 - chlorophenyl) - phenylmethyl] -4 - [ ( 3-methylphenyl ) methyl ]-piperazine ] were used.