Tolazoline Chemical Properties

Melting point:

66-69 °C(lit.)

Boiling point:

188°C/20mmHg(lit.)

Density 

1.0849 (rough estimate)

refractive index 

1.6392 (estimate)

storage temp. 

2-8°C

solubility 

alcohol: freely soluble

pka

pKa 10.3(H2O t undefined I = 0.1) (Uncertain)

form 

Solid

color 

Crystals from pet ether

Merck 

14,9506

CAS DataBase Reference

59-98-3(CAS DataBase Reference)

NIST Chemistry Reference

1H-Imidazole, 4,5-dihydro-2-(phenylmethyl)-(59-98-3)

EPA Substance Registry System

1H-Imidazole, 4,5-dihydro-2-(phenylmethyl)- (59-98-3)

Safety Information

Hazard Codes 

Xn

Risk Statements 

20/21/22-36/37/38

Safety Statements 

26-28-36/37/39-45

WGK Germany 

3

RTECS 

NJ1925000

HS Code 

2933299090

Toxicity

cyt-ham:lng 62,500 mg/L GMCRDC 27,95,81

MSDS

• Language:English Provider:SigmaAldrich

Tolazoline Usage And Synthesis

Originator

Priscoline,Ciba,US,1948

Uses

Tolazoline is used for treating stable forms of pulmonary hypertension in newborns, and in cases where systemic arterial oxygenation cannot be achieved in the usual manner under careful observation of professionals.

Uses

Reactant for synthesis of imidazoline-containing drug

Definition

ChEBI: A member of the class of imidazoles that is 4,5-dihydro-1H-imidazole substituted by a benzyl group.

Manufacturing Process

The phenyl-acetiminoether hydrochloride of the formula from 12 parts of benzylcyanide and ethanol and HCl is mixed with 8 parts of ethylenediamine hydrate which has been diluted with little alcohol, whereby the crystals go into solution. The whole is then heated on the water-bath until the ammonia odor has disappeared, cooled, concentrated caustic potash solution added, and the separated oil extracted with ether. The solution is dried with potassium carbonate and potassium hydroxide. After evaporation a pale oil is left which distills at 147°C under a pressure of 9 mm and which solidifies in the condenser to a white crystalline mass. The yield amounts to 90% of the theory. The hydrochloride melts at 168° to 170°C.

Therapeutic Function

Vasodilator

General Description

2-Benzylimidazoline is an active vasodilator.

Pharmacology

Tolazoline is a weak, reversible α-adrenoblocker that lowers resistance of peripheral blood vessels and elevates venous capacity. However, it also exhibits β-adrenomimetic activity, which consists of the stimulation of cardiac work and is manifest as tachycardia, cholinergic activity, which consists of stimulation of the gastrointestinal tract, and histamine-like activity, which consists of stimulation of gastric secretion.

Safety Profile

Poison by ingestion,intraperitoneal, and intravenous routes. Mutation data reported. When heated to decomposition it emits toxicfumes of NOx.

Synthesis

Tolazoline, 2-benzyl-2-imidazoline (12.2.7), is synthesized by the heterocyclation of the ethyl ester of iminophenzylacetic acid with ethylendiamine (12.2.6), which forms the desired product (12.2.7) [32¨C35]. The structure of tolazoline is strikingly similar to |á-adrenergic agonists, which are antiedema sympathomimetics.

Tolazoline(59-98-3)Related Product Information

• 2-METHYL-2-IMIDAZOLINE
• 2-Phenyl-2-imidazoline
• Benzyl alcohol
• Benzyltriethylammonium chloride
• Benzyltrimethylammonium chloride
• Dihydromyrcenol
• Dibenzylideneacetone
• 1,3-Dimethyl-2-imidazolidinone
• Imidazole
• Imidocarb dipropionate
• 1,1'-Carbonyldiimidazole
• 1-Methylimidazole
• Imidazolidine
• Benzyl chloride
• Benzyl
• Tetryzoline
• Naphazoline nitrate
• Domazoline