6-Chloro-5-fluoroindazole

6-Chloro-5-fluoroindazole Property

storage temp. 

Sealed in dry,Room Temperature

Appearance

White to off-white Solid

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

warning

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

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).

P330Rinse mouth.

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

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

P362Take off contaminated clothing and wash before reuse.

P403+P233Store in a well-ventilated place. Keep container tightly closed.

P405Store locked up.

P501Dispose of contents/container to..…

6-Chloro-5-fluoroindazole Chemical Properties,Usage,Production

Synthesis

The general procedure for the synthesis of 6-chloro-5-fluoro-1H-indazole from 4-chloro-2,5-difluorobenzaldehyde was as follows: a mixed solution of 4-chloro-2,5-difluorobenzaldehyde (20.6 g, 105.0 mmol) and hydrazine hydrate (77.2 mL, 1575.2 mmol, 15 eq.) in n-butanol (35 mL) was stirred and reacted for 3 days at 140 °C. Upon completion of the reaction, the mixture was cooled to room temperature and slowly poured into ice water (750 mL). Subsequently, the mixture was stirred vigorously for 2 h. The precipitated orange solid was collected by filtration. The filtrate was extracted with ethyl acetate (3 x 250 mL), the organic phases were combined and washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The concentrated residue was combined with the previously collected orange solid and purified by medium pressure liquid chromatography (MPLC, Biotage system, gradient elution, 25% ethyl acetate/hexane) to give 2.81 g (16% yield) of the target product, 6-chloro-5-fluoro-1H-indazole, as a white solid. The product was characterized by 1H-NMR (300 MHz, DMSO-d6): δ 13.3 (broad single peak, 1H), 8.09 (single peak, 1H), 7.80-7.76 (multiple peaks, 2H); ES-MS m/z 171.2/173.2 [M+H]+, retention time (RT) 3.02 min.

References

[1] Patent: WO2007/56170, 2007, A2. Location in patent: Page/Page column 95-96