4-Ethynylbenzoic acid is a biochemical compound that could be utilized as a biomaterial or organic/chemical reagent for biomedical research. 4-Ethynylbenzoic acid is a reagent for click chemistry. It contains Alkyne groups and could undergo CuAAc (copper-catalyzed azide-alkyne cycloaddition reaction) with compounds bearing an Azide group.

Physicochemical Properties

Molecular Formula	C9H6O2
Molecular Weight	146.14
Exact Mass	146.036
CAS #	10602-00-3
Related CAS #	192705-28-5
PubChem CID	589706
Appearance	Orange to reddish brown solid powder
Density	1.2±0.1 g/cm3
Boiling Point	277.2±23.0 °C at 760 mmHg
Melting Point	192 °C(dec.)
Flash Point	126.4±17.3 °C
Vapour Pressure	0.0±0.6 mmHg at 25°C
Index of Refraction	1.592
LogP	2.08
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	2
Rotatable Bond Count	2
Heavy Atom Count	11
Complexity	191
Defined Atom Stereocenter Count	0
InChi Key	SJXHLZCPDZPBPW-UHFFFAOYSA-N
InChi Code	InChI=1S/C9H6O2/c1-2-7-3-5-8(6-4-7)9(10)11/h1,3-6H,(H,10,11)
Chemical Name	4-ethynylbenzoic acid
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

Solubility Data

Solubility (In Vitro)

DMSO: 100 mg/mL (684.28 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (17.11 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 25.0 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: ≥ 2.5 mg/mL (17.11 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 25.0 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: ≥ 2.5 mg/mL (17.11 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 25.0 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	6.8428 mL	34.2138 mL	68.4275 mL
	5 mM	1.3686 mL	6.8428 mL	13.6855 mL
	10 mM	0.6843 mL	3.4214 mL	6.8428 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.