| Identification | Back Directory | [Name]
3-chloro-1H-pyrazole | [CAS]
14339-33-4 | [Synonyms]
EOS-61387
3-Chloroyrazole
5-Chloropyrazole
3-Chloropyrazole
3-chloro-1H-pyrazole
1H-Pyrazole, 3-chloro- | [Molecular Formula]
C3H3ClN2 | [MDL Number]
MFCD12756597 | [MOL File]
14339-33-4.mol | [Molecular Weight]
102.52 |
| Chemical Properties | Back Directory | [Melting point ]
40 °C | [Boiling point ]
250.9±13.0 °C(Predicted) | [density ]
1.405±0.06 g/cm3(Predicted) | [storage temp. ]
Inert atmosphere,2-8°C | [form ]
powder | [pka]
11.04±0.10(Predicted) | [color ]
White | [InChI]
InChI=1S/C3H3ClN2/c4-3-1-2-5-6-3/h1-2H,(H,5,6) | [InChIKey]
IJPFBRONCJOTTA-UHFFFAOYSA-N | [SMILES]
N1C=CC(Cl)=N1 |
| Hazard Information | Back Directory | [Uses]
5-Chloro-1h-pyrazole is used in preparation of aminoquinazolines as P2X3 inhibitors. | [Synthesis]
General procedure for the synthesis of 3-chloro-1H-pyrazole from 3-aminopyrazole: Concentrated hydrochloric acid (20 mL) was slowly added to a solution of acetonitrile (600 mL) containing 1H-pyrazol-3-amine (20.0 g, 241 mmol), followed by the addition of copper(II) chloride (65.0 g, 481 mmol) at 0 °C. The reaction mixture was stirred at 0 °C for 30 min followed by dropwise addition of isoamyl nitrite (56.4 g, 481 mmol). The reaction mixture was continued to be stirred at room temperature for 2 days. After completion of the reaction, the reaction was quenched with 10% aqueous ammonia solution (1 L). The aqueous phase was extracted with ethyl acetate (5 x 500 mL) and the combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by silica gel column chromatography (eluent: hexane/ethyl acetate=20:1) to afford the target product 3-chloro-1H-pyrazole (10.3 g, 42% yield) as a green oil.1H NMR (400 MHz, CDCl3): δ 12.84 (br s, 1H), 7.62 (s, 1H), 6.29 (s, 1H). | [References]
[1] Patent: WO2018/85247, 2018, A1. Location in patent: Paragraph 00296; 00297 |
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