WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 528510

CAS#: 91524-14-0

Description: Napamezole, also known as WIN-51181, is an α2 adrenergic receptor antagonist potentially for the treatment of major depressive disorder and anxiety. Napamezole reversed clonidine-induced decreased in twitch height in the electrically stimulated rat vas deferens. Napamezole also antagonized methoxamine-induced contractions (alpha-1) of the rat vas deferens with a Kb of 135 nM.

Price and Availability




Napamezole (WIN-51181) is not in stock, may be available through custom synthesis. For cost-effective reason, minimum 1 gram order is requested. The product will be characterized by NMR, HPLC and MS analysis. Purity (HPLC) is usually >98%. CoA, QC data, MSDS will be provided when product is successfully made. The estimated lead time is 2-3 months. Please send email to to inquire quote.

Chemical Structure


Theoretical Analysis

MedKoo Cat#: 528510
Name: Napamezole
CAS#: 91524-14-0
Chemical Formula: C14H16N2
Exact Mass: 212.1313
Molecular Weight: 212.296
Elemental Analysis: C, 79.21; H, 7.60; N, 13.20

Synonym: Napamezole; WIN-51181; WIN 51181; WIN51181

IUPAC/Chemical Name: 2-((3,4-dihydronaphthalen-2-yl)methyl)-4,5-dihydro-1H-imidazole


InChi Code: InChI=1S/C14H16N2/c1-2-4-13-9-11(5-6-12(13)3-1)10-14-15-7-8-16-14/h1-4,9H,5-8,10H2,(H,15,16)


Technical Data

Solid powder

>98% (or refer to the Certificate of Analysis)

Shipping Condition:
Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition:
Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Soluble in DMSO

Shelf Life:
>2 years if stored properly

Drug Formulation:
This drug may be formulated in DMSO

Stock Solution Storage:
0 - 4 C for short term (days to weeks), or -20 C for long term (months).

Harmonized System Code:


1: Cordi AA, Berque-Bestel I, Persigand T, Lacoste JM, Newman-Tancredi A, Audinot V, Millan MJ. Potential antidepressants displayed combined alpha(2)-adrenoceptor antagonist and monoamine uptake inhibitor properties. J Med Chem. 2001 Mar 1;44(5):787-805. PubMed PMID: 11262089.

2: Perrone MH, Luttinger D, Hamel LT, Fritz PM, Ferraino R, Haubrich DR. In vivo assessment of napamezole, an alpha-2 adrenoceptor antagonist and monoamine re-uptake inhibitor. J Pharmacol Exp Ther. 1990 Aug;254(2):476-83. PubMed PMID: 1974638.

3: Perrone MH, Hamel LT, Ferrari RA, Haubrich DR. Napamezole, an alpha-2 adrenergic receptor antagonist and monoamine uptake inhibitor in vitro. J Pharmacol Exp Ther. 1990 Aug;254(2):471-5. PubMed PMID: 1974637.

4: Wentland MP, Bailey DM, Alexander EJ, Castaldi MJ, Ferrari RA, Haubrich DR, Luttinger DA, Perrone MH. Synthesis and antidepressant properties of novel 2-substituted 4,5-dihydro-1H-imidazole derivatives. J Med Chem. 1987 Aug;30(8):1482-9. PubMed PMID: 3039138.