A-381393 is a potent, selective, BBB (blood-brain barrier) permeable/penetrable dopamine D4 receptor blocker (antagonist) with Kis of 1.5, 1.9 and 1.6 for human dopamine D4.4, D4.2 and D4.7 receptors respectively. nM, the selectivity is more than 2700 times that of D1, D2, D3, and D5 dopamine receptors. A-381393 is moderately selective for 5-HT2A with Ki of 370 nM.

Physicochemical Properties

Molecular Formula	C20H24N4
Molecular Weight	320.431
Exact Mass	320.2
Elemental Analysis	C, 74.97; H, 7.55; N, 17.48
CAS #	726174-00-1
PubChem CID	11301655
Appearance	Solid powder
LogP	3.7
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	3
Heavy Atom Count	24
Complexity	406
Defined Atom Stereocenter Count	0
InChi Key	SAQMCVDGOIRQTC-UHFFFAOYSA-N
InChi Code	InChI=1S/C20H24N4/c1-15-7-8-17(13-16(15)2)24-11-9-23(10-12-24)14-20-21-18-5-3-4-6-19(18)22-20/h3-8,13H,9-12,14H2,1-2H3,(H,21,22)
Chemical Name	2-[[4-(3,4-dimethylphenyl)piperazin-1-yl]methyl]-1H-benzimidazole
Synonyms	A 381393; A381393; A-381393
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	D4.4 receptor ( Ki = 1.5 nM ); D4.2 receptor ( EC50 = 1.9 nM ); D4.7 receptor ( EC50 = 1.6 nM )
ln Vitro	A-381393, with Kis of 1365, 8600, 2044, 1912, and 2962 nM, respectively, shows weak affinity at 5-HT1A, Sigma 2, Adenoceptor α1A, Adenoceptor α2C, and Histamine H1[1].
References	[1]. 2-[4-(3,4-Dimethylphenyl)piperazin-1-ylmethyl]-1H benzoimidazole (A-381393), a selective dopamine D4 receptor antagonist. Neuropharmacology. 2005 Jul;49(1):112-21.

Solubility Data

Solubility (In Vitro)

DMSO: ~51.7 mg/mL (~161.3 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.58 mg/mL (8.05 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.58 mg/mL (8.05 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 2.58 mg/mL (8.05 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.1208 mL	15.6040 mL	31.2081 mL
	5 mM	0.6242 mL	3.1208 mL	6.2416 mL
	10 mM	0.3121 mL	1.5604 mL	3.1208 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.