Desmethyl Erlotinib (OSI-420 free base) is the bioactive metabolite of Erlotinib, an EGFR tyrosine kinase inhibitor. Desmethyl Erlotinib 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	C21H21N3O4
Molecular Weight	379.41
Exact Mass	379.153
CAS #	183321-86-0
Related CAS #	Desmethyl Erlotinib hydrochloride;183320-51-6;Desmethyl Erlotinib-d4;1216420-11-9
PubChem CID	10317566
Appearance	White to off-white solid powder
Density	1.3±0.1 g/cm3
Boiling Point	572.8±50.0 °C at 760 mmHg
Flash Point	300.2±30.1 °C
Vapour Pressure	0.0±1.7 mmHg at 25°C
Index of Refraction	1.644
LogP	1.75
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	7
Rotatable Bond Count	10
Heavy Atom Count	28
Complexity	511
Defined Atom Stereocenter Count	0
InChi Key	KOQIAZNBAWFSQM-UHFFFAOYSA-N
InChi Code	InChI=1S/C21H21N3O4/c1-3-15-5-4-6-16(11-15)24-21-17-12-19(27-8-7-25)20(28-10-9-26-2)13-18(17)22-14-23-21/h1,4-6,11-14,25H,7-10H2,2H3,(H,22,23,24)
Chemical Name	2-[4-(3-ethynylanilino)-7-(2-methoxyethoxy)quinazolin-6-yl]oxyethanol
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

ln Vivo	In a pharmacokinetic investigation conducted in Wistar rats, desmethyl erlotinib showed a t1/2 of 11.96±2.01 h[1].
References	[1]. Simultaneous Determination of Celecoxib, Erlotinib, and its Metabolite Desmethyl-Erlotinib (OSI-420) in Rat Plasma by Liquid chromatography/Tandem Mass Spectrometry with Positive/Negative Ion-Switching Electrospray Ionisation.Sci Pharm. 2012 Jul-Sep;80(3):633-46.

Solubility Data

Solubility (In Vitro)

DMSO: 125 mg/mL (329.46 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (5.48 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 20.8 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: ≥ 2.08 mg/mL (5.48 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 20.8 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: ≥ 2.08 mg/mL (5.48 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 20.8 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	2.6357 mL	13.1784 mL	26.3567 mL
	5 mM	0.5271 mL	2.6357 mL	5.2713 mL
	10 mM	0.2636 mL	1.3178 mL	2.6357 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.