4-Chloro-5-Bromopyrimidine

4-Chloro-5-Bromopyrimidine Property

Boiling point:

250.7±20.0 °C(Predicted)

Density 

1.859±0.06 g/cm3(Predicted)

storage temp. 

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

pka

-1.41±0.16(Predicted)

Appearance

Colorless to light yellow Liquid

Safety

HS Code 

2933599590

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-Chloro-5-Bromopyrimidine Chemical Properties,Usage,Production

Chemical Properties

Pale yellow crystal

Synthesis

The general procedure for the synthesis of 4-chloro-5-bromopyrimidine using 5-bromopyrimidin-4-one as starting material was as follows: to a mixture of 5-bromopyrimidin-4-ol (40 g, 0.22 mol) dissolved in POCl3 (300 mL) was added drop-wise DIPEA (29 g, 0.22 mol) at room temperature. Subsequently, the reaction mixture was heated to reflux and maintained for 3 hours. The progress of the reaction was monitored by TLC (unfolding agent ratio of petroleum ether/EtOAc 1:1) to confirm the completion of the reaction. Upon completion of the reaction, excess POCl3 was removed by distillation under reduced pressure. the residue was slowly poured into ice water (300 mL) under stirring. The aqueous phase was extracted with EtOAc (2 × 300 mL), the organic layers were combined and washed sequentially with water (300 mL) and brine (300 mL), dried over Na2SO4 and finally concentrated under vacuum. The residue was purified by silica gel column chromatography (eluent ratio of petroleum ether/EtOAc, gradient from 20:1 to 10:1) to afford the target product 5-bromo-4-chloropyrimidine (25 g, 60% yield) as a yellow oil.

References

[1] Patent: WO2016/97918, 2016, A1. Location in patent: Page/Page column 88
[2] Patent: WO2012/135631, 2012, A1. Location in patent: Page/Page column 21-22
[3] Patent: WO2010/88518, 2010, A2. Location in patent: Page/Page column 86-87
[4] Organic Process Research and Development, 2000, vol. 4, # 4, p. 275 - 285