1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one Chemical Properties

Melting point:

231°C

Density 

1.51±0.1 g/cm3(Predicted)

storage temp. 

2-8°C

solubility 

DMSO (Slightly), Methanol (Slightly, Heated, Sonicated)

pka

7.86±0.20(Predicted)

form 

Solid

color 

Light Brown to Brown

BRN 

607433

Stability:

Light Sensitive

InChI

InChI=1S/C6H5N3O/c10-6-8-7-5-3-1-2-4-9(5)6/h1-4H,(H,8,10)

InChIKey

LJRXNXBFJXXRNQ-UHFFFAOYSA-N

SMILES

C12=NNC(=O)N1C=CC=C2

LogP

0.113

CAS DataBase Reference

6969-71-7(CAS DataBase Reference)

Safety Information

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36

WGK Germany 

3

HS Code 

29339900

MSDS

• Language:English Provider:ALFA

1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one Usage And Synthesis

Chemical Properties

Beige Solid

Uses

1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one was used to prepare a congener of Trazodone (T718500) which was found to be a potent and selective inhibitor of synaptosomal uptake of 5-hydroxytryptamine.

Synthesis Reference(s)

Journal of Medicinal Chemistry, 28, p. 1394, 1985 DOI: 10.1021/jm00148a004

Synthesis

General procedure for the synthesis of [1,2,4]triazolo[4,3-a]pyridin-3-(2H)-one from 2-chloropyridine and aminourea hydrochloride: 2-chloropyridine (5.0 g, 44.03 mmol), aminourea hydrochloride (9.8 g, 88.06 mmol), and 2-ethoxyethanol (15 mL) were mixed and heated to reflux. Concentrated hydrochloric acid (0.1 mL dissolved in 1 mL of 2-ethoxyethanol) was slowly added to the reaction mixture. The reaction was kept at reflux for 24 hours and subsequently cooled to about 60 °C and diluted with deionized water (15 mL). The resulting light yellow solid product was collected by filtration and washed with deionized water to afford the title compound (2.2 g, 51% yield). The melting point of the product was 235-240°C. 1H NMR (300 MHz, DMSO-d6) δ 6.51-6.60 (m, 1H), 7.05-7.22 (m, 2H), 7.80 (d, J=7.1 Hz, 1H), 12.45 (br, 1H, exchangeable with D2O); IR (KBr) ν 3173, 3098. 3048, 1717, 1634, 1536, 1348 cm-1; MS 136 (M+1).

References

[1] Patent: US2009/209550, 2009, A1. Location in patent: Page/Page column 25-26
[2] Patent: US4254124, 1981, A

1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one(6969-71-7)Related Product Information

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