1-(1-methyl-1H-pyrazol-5-yl)ethanone

1-(1-methyl-1H-pyrazol-5-yl)ethanone Property

storage temp. 

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

InChI

InChI=1S/C6H8N2O/c1-5(9)6-3-4-7-8(6)2/h3-4H,1-2H3

InChIKey

UXNMMULCZUAIHE-UHFFFAOYSA-N

SMILES

C(=O)(C1N(C)N=CC=1)C

Safety

HS Code 

2933199090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H227Combustible liquid

H315Causes skin irritation

H319Causes serious eye irritation

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

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

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P337+P313IF eye irritation persists: Get medical advice/attention.

P370+P378In case of fire: Use … for extinction.

P403+P235Store in a well-ventilated place. Keep cool.

P501Dispose of contents/container to..…

1-(1-methyl-1H-pyrazol-5-yl)ethanone Chemical Properties,Usage,Production

Synthesis

The general procedure for the synthesis of 3-acetyl-1-methyl-1H-pyrazole and 1-methyl-5-acetyl-pyrazole from 3-acetylpyrazole and iodomethane was as follows: to a stirred solution of 1-(1H-pyrazol-5-yl)acetophenone (8.24 g, 74.8 mmol) and potassium carbonate (20.58 g, 149 mmol) in acetonitrile (50 mL) was added iodomethane ( 4.68 mL, 74.8 mmol). The reaction mixture was stirred at room temperature for 3 days. Upon completion of the reaction, water was added to the mixture and extracted with ethyl acetate. The organic layers were combined, washed with brine, dried over magnesium sulfate, filtered and concentrated in vacuum. The crude product was purified by silica gel column chromatography (5:1 to 2:1 linear gradient of hexane/ethyl acetate) to afford 1-(1-methyl-1H-pyrazol-5-yl)ethanone (1.20 g, 9.67 mmol, 13% yield, less polar fraction, eluted first) and 1-(1-methyl-1H-pyrazol-3-yl)ethanone (5.40 g, 43.5 mmol , 58% yield, more polar fraction, eluted subsequently).NMR hydrogen spectral (500 MHz, CDCl3) data for 1-(1-methyl-1H-pyrazol-5-yl)ethanone: δ 7.47 (d, J=2.0 Hz, 1H), 6.83 (d, J=2.1 Hz, 1H), 4.17 (s, 3H), 2.52 (s, 3H). Mass spectrum (M+H)+: 125.2. NMR hydrogen spectrum (500 MHz, CDCl3) data of 1-(1-methyl-1H-pyrazol-3-yl)ethanone: δ 7.38 (d, J=2.3Hz, 1H), 6.78 (d, J=2.4Hz, 1H), 3.98 (s, 3H), 2.57 (s, 3H). Mass spectrum (M+H)+: 125.2.

References

[1] Patent: WO2014/98831, 2014, A1. Location in patent: Page/Page column 72