METHAPYRILENE HYDROCHLORIDE Property

Melting point:

162°

storage temp. 

room temp

solubility 

DMF: 15 mg/ml,DMSO: 10 mg/ml,Ethanol: 1 mg/ml,PBS (pH 7.2): 1 mg/ml

form 

Solid

color 

Off-white to yellow

Stability:

Hygroscopic

EPA Substance Registry System

Methapyrilene hydrochloride (135-23-9)

Safety

Hazard Codes 

T

Risk Statements 

25

Safety Statements 

22-36-45

RIDADR 

UN 2811 6.1/PG 3

WGK Germany 

3

RTECS 

UT1750000

HazardClass 

6.1(b)

PackingGroup 

III

Toxicity

LD50 oral in rat: 200mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H301Toxic if swalloed

Precautionary statements

P301+P310IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician.

METHAPYRILENE HYDROCHLORIDE Chemical Properties,Usage,Production

Originator

Thenylene ,Abbott,US,1947

Uses

Antihistaminic;Histamine H1 antagonist

Uses

Methapyrilene is used as antihistaminic agent.

Definition

ChEBI: A hydrochloride that is the monohydrochloride salt of methapyrilene.

Manufacturing Process

To a slurry of sodamide in 200 cc of toluene representing 6.7 g of sodium was added at 30° to 40°C, 32.3 g (0.31 mol) of 2-aminopyridine. The mixture was heated to reflux temperature and was refluxed for 1? hours. To the resulting mixture was added over a period of approximately one hour a solution of 32 g of freshly distilled N,N-dimethyl-β-chloroethylamine in 40 to 50 cc of dry toluene, The reaction mixture was then heated for 2 hours at reflux temperature. Thereafter, 200 cc of water was added and the toluene layer was separated and washed with water. The toluene was stripped from the mixture by distillation and the residue was distilled under reduced pressure. The distillate was refractionated and the portion distilled at 93° to 103°C/1 mm was recovered. Yield of N-(2-pyridyl)-N',N'-dimethyl-ethylenediamine, 60%.
A solution of 20 g (0.121 mol) of N-(2-pyridyl)-N',N'-dimethylethylenediamine in 25 cc of toluene was added to a slurry of sodamide in 100 cc of toluene representing 2.8 g of sodium. The mixture was refluxed for one hour. To this mixture was added over a period of ? hour a solution of 16 g (0.121 mol) of 2-thenyl chloride in 25 cc of toluene. The resulting reaction mixture was refluxed for 3 hours. Thereafter, water was added and the toluene layer was separated and washed with water.
The toluene was then stripped off by distillation and the residue was distilled under reduced pressure. The main fraction was redistilled. Yield of N-(2- pyridyl)-N-(2-thenyl)-N',N'-dimethyl-ethylenediamine was 69%; BP 130° to 140°C/0.4 mm. A portion of the product was dissolved in ether and an ether solution of hydrogen chloride was added. The monohydrochloride of N-(2- pyridyl)-N-(2-thenyl)-N',N'-dimethyl-ethylenediamine which separated was washed with ether and dried.

Therapeutic Function

Antihistaminic

General Description

Methapyrilene hydrochloride,2-[[2-(dimethylamino)-ethyl]-2-thienylarnino]pyridine monohydrochloride (Histadyl) is available as the bitter-tasting, white crystalline powder that is soluble in water(1:0.5), in alcohol (1:5), and in chloroform (1:3). Its solutionshave a pH of about 5.5. It differs structurally from tripelennaminein having a 2-thiophene—methylene group in placeof the benzyl group. The thiophene ring is considered isostericwith the benzene ring, and the isosteres exhibit similaractivity. A study of the solid-state conformation of methapyrilenehydrochloride showed that the trans-conformation is preferredfor the two ethylenediamine nitrogen atoms. The Foodand Drug Administration declared methapyrilene a potentialcarcinogen in 1979, and all products containing it have beenrecalled.

General Description

White crystalline powder or solid with a faint odor. Bitter taste. pH (aqueous solution) 5.5.

Air & Water Reactions

Water soluble.

Reactivity Profile

METHAPYRILENE HYDROCHLORIDE is light sensitive. Solutions of METHAPYRILENE HYDROCHLORIDE in water, DMSO, 95% ethanol or acetone should be stable for 24 hours under normal lab conditions. . Organosulfides are incompatible with acids, diazo and azo compounds, halocarbons, isocyanates, aldehydes, alkali metals, nitrides, hydrides, and other strong reducing agents. Reactions with these materials generate heat and in many cases hydrogen gas.

Fire Hazard

Flash point data for METHAPYRILENE HYDROCHLORIDE are not available; however, METHAPYRILENE HYDROCHLORIDE is probably combustible.