HOAt Chemical Properties

Melting point:

213-216°C

Boiling point:

250.36°C (rough estimate)

Density 

0.973 g/mL at 20 °C

refractive index 

n20/D 1.441

Flash point:

213-216°C

storage temp. 

Store at RT.

solubility 

>6.8mg/mL in DMSO

form 

Powder

pka

5.85±0.58(Predicted)

color 

White to yellow

Decomposition 

213-216 ºC

InChI

InChI=1S/C5H4N4O/c10-9-5-4(7-8-9)2-1-3-6-5/h1-3,10H

InChIKey

FPIRBHDGWMWJEP-UHFFFAOYSA-N

SMILES

C12N(O)N=NC1=CC=CN=2

CAS DataBase Reference

39968-33-7(CAS DataBase Reference)

EPA Substance Registry System

3H-1,2,3-Triazolo[4,5-b]pyridine, 3-hydroxy- (39968-33-7)

Safety Information

Hazard Codes 

T,Xi,F,Xn,E

Risk Statements 

61-20/21-36-5-36/37/38-11-41-37/38-22-2-36/37

Safety Statements 

53-45-37/39-26-16-39-35-36-36/37-28-15

RIDADR 

UN 1993 3/PG 3

WGK Germany 

1

HazardClass 

IRRITANT

PackingGroup 

Ⅱ

HS Code 

29332990

MSDS

• Language:English Provider:SigmaAldrich

HOAt Usage And Synthesis

Description

HOAt (also known as 1-Hydroxy-7-azabenzotriazole) is a benzotriazole compound commonly used as a coupling reagent for amino acids and peptides. HOAt is also used as a solid-phase synthesis reagent for chiral peptide nucleic acids.

Chemical Properties

Clear, colorless liquid

Uses

1-Hydroxy-7-azabenzotriazole can be used as antibacterial, anti-aging and flame-retardant dendritic polyacrylate emulsion.

Application

HOAt is a triazole derivative used in amide coupling chemistry as an additive in combination with coupling agents. The most used coupling reagents with HOAt are the carbodiimides EDCI, DCC and DIC. HOAt is comparable to HOBt but gives a better performance. It has faster reaction rates, reduced racemisation, higher yields and visual indication of the reaction endpoint by colour change of the reaction mixture from yellow to colourless. The increased efficiency of HOAt compared to HOBt is related to the stabilisation of the activated intermediate via anchimeric effect, due to the formation of a hydrogen bond with the N atom in position 7 of the benzotriazole. As is HOBt, HOAt is explosive and is therefore required to be handled carefully.

General Description

HOAt is a commonly used peptide bond forming agent that may become an impurity in drug synthesis, but is not mutagenic. HOAt can be used for peptide fragment polycondensation and can also inhibit the racemization of peptide polycondensation.

reaction suitability

reaction type: Addition Reactions

Precautions

3-Hydroxy-3H-1,2,3-triazolo[4,5-b]pyridine is stable, not hygroscopic, and can be stored indefinitely. HOAt (3-Hydroxy-3H-1,2,3-triazolo[4,5-b]pyridine) solutions in DMF (0.3 M) can be stored in an inert atmosphere for weeks. Syntheses of peptides carried out with freshly prepared and 4-week-old solutions show similar quality to the crude product. Violent decomposition may occur when dried at elevated temperatures.

HOAt(39968-33-7)Related Product Information

• 1,2,3-1H-Triazole
• 1-Hydroxybenzotriazole
• 5-Methyl-1H-benzotriazole
• 1H-Benzotriazole
• 1,2,4-Triazole
• HATU
• N-CHLOROSACCHARIN
• 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride
• O-(6-Chlorobenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate
• 3-Hydroxy-1,2,3-benzotriazin-4(3H)-one
• HBTU
• 1-Hydroxybenzotriazole hydrate
• CHLOROPHOSPHONAZO III
• 2-(7-Azabenzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate
• N-Hydroxyphthalimide
• TBTU
• HOAt
• (3-Hydroxy-3H-1,2,3-triazolo[4,5-b]pyridinato-O)tri-1-pyrrolidinylphosphonium hexafluorophosphate