phentolamine

Description

phentolamine · CAS 50-60-2 · C17H19N3O. UNII Z468598HBV. Melting Point: 181; Melting Point: 175 °C; Melting Point: 174.5 °C.

Identification

CAS Registry Number	50-60-2
PubChem CID	5775
Molecular formula	C17H19N3O
IUPAC name	3-[N-(4,5-dihydro-1H-imidazol-2-ylmethyl)-4-methylanilino]phenol
UNII (FDA)	Z468598HBV

Computed Descriptors

Molecular Weight	281.35
XLogP3	2.6
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	4
Exact Mass	281.152812238
Monoisotopic Mass	281.152812238
Topological Polar Surface Area	47.9
Heavy Atom Count	21
Formal Charge	0

Physical & Chemical Properties

Melting Point	181
Melting Point	175 °C
Melting Point	174.5 °C
Solubility	2.72e-01 g/L
LogP	3.3

Physical description & handling notes

• Solid
• Crystals
• Bitter crystals; MP: 239-240 °C. One gram dissolves in 50 mL water, in 70 mL alcohol. Very slightly soluble in chloroform. Practically insoluble in acetone, ethyl acetate. pH of 1% aqueous solution 4.5 to 5.5. Aqueous solutions cannot be stored. /Phentolamin hydrochloride/
• Following reconstitution of the commercially available lyophilized powder with sterile water for injection to a concentration of 5 mg/mL, phentolamine mesylate injection is stable for 48 hours at room temperature or 1 week at 2-8 °C; however, the manufacturer recommends that the reconstituted injection be used immediately and not stored.
• 166.27 Ų [M+K]+ [CCS Type: TW; Method: calibrated with polyalanine and drug standards]
• 156.25 Ų [M+H-H2O]+ [CCS Type: TW; Method: calibrated with polyalanine and drug standards]

GHS Hazard Classification

Reported hazard statements	H302 (100%), H315 (100%), H319 (100%)

Documented Uses

• Treatment of hypertension and hypertensive emergencies, pheochromocytoma, vasospasm of Raynaud disease and frostbite, clonidine withdrawal syndrome, impotence, and peripheral vascular disease
• To relieve pseudo-obstruction of the bowel in patients with pheochromocytoma; to prevent dermal necrosis after inadvertent extravasation of an alpha-receptor antagonist; for treatment of hypertensive crisis that follow the abrupt withdrawal of clonidine or that may result from the ingestion of tyramine-containing food during the use of nonselective MAO inhibitors.
• THERAPEUTIC CATEGORY: Antihypertensive in treatment of pheochromocytoma; diagnostic aid (pheochromocytoma). In treatment of male erectile dysfunction.
• m-(p-Toluidino)phenol is refluxed with 2-chloromethylimidazoline hydrochloride and the resulting phentolamine base treated with an equimolar protion of methanesulfonic acid. /Phentolamine mesylate/
• No longer widely used because of its side effects /which include arrhythmia and tachycardia/.
• When used intravenously or intramuscularly, phentolamine is used to prevent or control hypertensive episodes that may occur in a patient with pheochromocytoma due to stress or manipulation during preoperative preparation and surgical excision. It is also used to prevent or treat dermal necrosis and sloughing following intravenous administration or extravasation of norepinephrine. It may be used to diagnose pheochromocytoma by the phentolamine-blocking test. Submucosal injection of phentolamine is indicated for the

Synonyms

phentolamine; 50-60-2; Regitin; Dibasin; Fentolamin; Fentolamina; Rogitine; Phentolaminum; C 7337 Ciba; Phentolamin; 2-(N-(m-Hydroxyphenyl)-p-toluidinomethyl)imidazoline; C 7337; DTXSID4023462; 2-(m-Hydroxy-N-p-tolylanilinomethyl)-2-imidazoline; 3-[(4,5-dihydro-1H-imidazol-2-ylmethyl)(4-methylphenyl)amino]phenol; 2-((N-(m-Hydroxyphenyl)-p-toluidino)methyl)-2-imidazoline

Frequently Asked Questions

What are the CAS number and molecular formula of phentolamine?

CAS 50-60-2; molecular formula C17H19N3O; molecular weight — g/mol.

What other names is phentolamine known by?

phentolamine, 50-60-2, Regitin, Dibasin, Fentolamin, Fentolamina.

Is phentolamine classified as hazardous?

Hazard statements reported: H302, H315, H319.

What are the key physical properties of phentolamine?

Melting Point: 181; Melting Point: 175 °C; Melting Point: 174.5 °C; Solubility: 2.72e-01 g/L.

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.