4-BROMO-1-METHYL-1H-PYRAZOLE-5-CARBALDEHYDE

4-BROMO-1-METHYL-1H-PYRAZOLE-5-CARBALDEHYDE Property

Melting point:

102-103°C

Boiling point:

275.2±20.0 °C(Predicted)

Density 

1.73±0.1 g/cm3(Predicted)

storage temp. 

under inert gas (nitrogen or Argon) at 2-8°C

pka

-1.48±0.10(Predicted)

Sensitive 

Air Sensitive

CAS DataBase Reference

473528-88-0

Safety

Risk Statements 

36/37/38

Safety Statements 

26-36/37/39

HS Code 

2933119000

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

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.

4-BROMO-1-METHYL-1H-PYRAZOLE-5-CARBALDEHYDE Chemical Properties,Usage,Production

Synthesis

General procedure for the synthesis of 1-methylpyrazole-5-carboxaldehyde using 1-methyl-1H-pyrazole-5-carboxaldehyde as starting material: a solution of N,N-dimethylformamide (DMF, 5 mL) of N-bromosuccinimide (NBS, 1.62 g, 9.09 mmol) was slowly added dropwise to a solution of 1-methyl-1H-pyrazole-5-carboxaldehyde (1.0 g, 9.09 mmol) solution in DMF (8 mL). The reaction mixture was stirred at room temperature overnight. Subsequently, 1N sodium hydroxide solution (9.1 mL) was added and stirring was continued for 10 min. The reaction solution was diluted with water (100 mL) and extracted with ethyl acetate (EtOAc, 30 mL x 3). The organic phases were combined, dried with anhydrous magnesium sulfate (MgSO4), filtered and concentrated to give an orange solid product (1.57 g, 92% yield). Liquid phase mass spectrometry (LRMS) detection showed m/z (M+H) of 187.9 and the measured value was 188.0.

References

[1] Patent: WO2014/81619, 2014, A1. Location in patent: Page/Page column 47
[2] Chemistry - A European Journal, 2018, vol. 24, # 38, p. 9530 - 9534