4-(1H-Pyrazol-4-yl)aniline

4-(1H-Pyrazol-4-yl)aniline Property

Melting point:

150-153 °C

Boiling point:

398.6±25.0 °C(Predicted)

Density 

1.238±0.06 g/cm3(Predicted)

storage temp. 

Keep in dark place,Inert atmosphere,Room temperature

pka

15.22±0.50(Predicted)

Appearance

Light brown to brown Solid

InChI

InChI=1S/C9H9N3/c10-9-3-1-7(2-4-9)8-5-11-12-6-8/h1-6H,10H2,(H,11,12)

InChIKey

NIIAGRDJQKKSKU-UHFFFAOYSA-N

SMILES

C1(N)=CC=C(C2=CNN=C2)C=C1

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H312Harmful in contact with skin

H315Causes skin irritation

H319Causes serious eye irritation

H332Harmful if inhaled

H335May cause respiratory irritation

Precautionary statements

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

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P270Do not eat, drink or smoke when using this product.

P271Use only outdoors or in a well-ventilated area.

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

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

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

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.

P312Call a POISON CENTER or doctor/physician if you feel unwell.

P321Specific treatment (see … on this label).

P322Specific measures (see …on this label).

P330Rinse mouth.

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

P362Take off contaminated clothing and wash before reuse.

P363Wash contaminated clothing before reuse.

P501Dispose of contents/container to..…

4-(1H-Pyrazol-4-yl)aniline Chemical Properties,Usage,Production

Synthesis

General procedure for the synthesis of 4-(1H-pyrazol-4-yl)aniline from 4-(4-nitrophenyl)-1H-pyrazole: 4-(4-nitrophenyl)-1H-pyrazole (8.3 g, 43.88 mmol) was suspended in a mixed solvent of MeOH/DME (2:1 v/v) with the addition of 10% Pd/C (wet wt, 415 mg). The reaction flask was evacuated under vacuum and then filled with hydrogen (supplied via a balloon) and this process was repeated three times. The reaction mixture was stirred at room temperature and the reaction process was monitored by LC-MS for amine formation. After 2.5 hours of stirring, LC-MS and TLC analysis showed that a small amount of starting material was still present in the reaction. Additional catalyst (200 mg) was added to the reaction mixture and the reaction was recharged with hydrogen.The reaction was examined after 2 hrs and it was confirmed that the starting material had been completely consumed and the reaction was complete. The reaction mixture was filtered through diatomaceous earth and the diatomaceous earth was washed with MeOH. The filtrate was concentrated under reduced pressure to give 6.59 g of yellow solid product (94% yield). The product was characterized by 1H NMR (400 MHz, DMSO-d6): δ 12.68 (br s, 1H), 7.80 (s, 2H), 7.23 (d, J = 8.0 Hz, 2H), 6.54 (d, J = 8.0 Hz, 2H), 4.97 (s, 2H). Mass spectrum (ES+) m/z 160 ([M+H]+).

References

[1] Patent: WO2016/210331, 2016, A1. Location in patent: Paragraph 0087; 0088
[2] Patent: WO2016/210330, 2016, A1. Location in patent: Paragraph 0091-0092
[3] Indian Journal of Chemistry, Section B: Organic Chemistry Including Medicinal Chemistry, 1987, vol. 26, # 1-12, p. 616 - 619