N-ETHYLBENZISOXAZOLIUM TETRAFLUOROBORATE Property

Melting point:

108-110 °C(lit.)

storage temp. 

Store at 0-5°C

solubility 

sol acetonitrile; slightly sol dichloromethane; sol aqueous acid (unstable above pH 4).

form 

crystalline solid

Sensitive 

Hygroscopic

CAS DataBase Reference

4611-62-5(CAS DataBase Reference)

Safety

Risk Statements 

36/37/38

Safety Statements 

22-24/25

WGK Germany 

3

F 

3-8-10-21

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P405Store locked up.

N-ETHYLBENZISOXAZOLIUM TETRAFLUOROBORATE Chemical Properties,Usage,Production

Description

N-Ethylbenzisoxazolium Tetrafluoroborate is a peptide-coupling reagent; reacts with a wide range of nucleophiles to give o-hydroxy-N-ethylbenzamido derivatives.

Synthesis

N-Ethylbenzisoxazolium Tetrafluoroborate is prepared by ethylation of benzisoxazole with purified Triethyloxonium Tetrafluoroborate.

storage

The salt is reported not to be hygroscopic, although it etches glass on long exposure to moist air; should be protected from light; reported to be an irritant.

Purification Methods

Recrystallise it from MeCN/EtOAc to give magnificent crystals. It is not hygroscopic but on long exposure to moisture it etches glass. It is light-sensitive and should be stored in brown glass bottles. UV (H2O), max 258nm ( 13 100) and 297nm ( 2 900), IR (CH2Cl2):max 1613 (C=N) and 1111-1000 (BF 4 ) [UV, IR, NMR: Kemp & Woodward Tetrahedron 21 3019 1965].