5H-Cyclopenta[b]pyridine, 4-chloro-6,7-dihydro- Chemical Properties

Boiling point:

234℃

Density 

1.241

Flash point:

118℃

storage temp. 

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

pka

4.34±0.20(Predicted)

Appearance

Colorless to light yellow Liquid

Safety Information

HS Code 

2933399990

5H-Cyclopenta[b]pyridine, 4-chloro-6,7-dihydro- Usage And Synthesis

Synthesis

6,7-Dihydro-5H-cyclopenta[b]pyridine 1-oxide (2.5 g, 18 mmol) was mixed with phosphoryl chloride (20 mL, 200 mmol). The reaction mixture was stirred at 120 °C for 3 hours. Upon completion of the reaction, the excess POCl3 was removed by distillation under reduced pressure.The residue was diluted with 80 mL of EtOAc and neutralized to pH 7-8 with Na2CO3 solution.After filtration, the aqueous layer was extracted twice (40 mL each) with EtOAc. The organic extracts were combined, dried with anhydrous Na2SO4, filtered and concentrated under reduced pressure to give 4-chloro-6,7-dihydro-5H-cyclopenta[b]pyridine (2.6 g, 93% yield). LCMS analysis: calculated value of C8H9ClN(M + H)+: m/z = 154.2; measured value: 154.3.

References

[1] Patent: US2014/200216, 2014, A1. Location in patent: Paragraph 0532; 0533
[2] Patent: US2014/200227, 2014, A1. Location in patent: Paragraph 0641; 0642
[3] Patent: WO2016/196244, 2016, A1. Location in patent: Page/Page column 195
[4] Patent: WO2009/19274, 2009, A1. Location in patent: Page/Page column 32
[5] Advanced Synthesis and Catalysis, 2007, vol. 349, # 14-15, p. 2345 - 2352