1H-Pyrazolo[3,4-b]pyridine, 3-bromo-5-nitro-

1H-Pyrazolo[3,4-b]pyridine, 3-bromo-5-nitro- Property

storage temp. 

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

Appearance

Off-white to light yellow 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..…

1H-Pyrazolo[3,4-b]pyridine, 3-bromo-5-nitro- Chemical Properties,Usage,Production

Synthesis

The general procedure for the synthesis of 3-bromo-5-nitro-1H-pyrazolo[3,4-b]pyridine from 5-nitro-7-azaindazole was as follows: a 4N NaOH solution (5.12 mL, 20.5 mmol) was slowly added to a dioxane (30 mL) solution of 5-nitro-1H-pyrazolo[3,4-b]pyridine (0.84 g, 5.12 mmol) at 0 °C. ) solution, followed by dropwise addition of bromine (1.05 mL, 20.5 mmol). After removal of the ice bath, the reaction mixture was stirred at room temperature for 30 min. Upon completion of the reaction, the reaction mixture was diluted with ethyl acetate (100 mL) and the reaction was quenched with saturated aqueous Na2S2O3 solution (50 mL). The aqueous layer was further extracted with ethyl acetate (100 mL). The organic layers were combined, dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography using hexane/ethyl acetate (9:1, v/v) as eluent to afford 3-bromo-5-nitro-1H-pyrazolo[3,4-b]pyridine (1.10 g, 88% yield) as solid.

References

[1] Patent: WO2011/25968, 2011, A1. Location in patent: Page/Page column 49
[2] Patent: WO2009/111279, 2009, A1. Location in patent: Page/Page column 96
[3] ACS Medicinal Chemistry Letters, 2011, vol. 2, # 5, p. 342 - 347