5-Ethynyl-2,2'-bipyridine

5-Ethynyl-2,2'-bipyridine Property

Melting point:

87-89 °C

Boiling point:

312.4±32.0 °C(Predicted)

Density 

1.17±0.1 g/cm3(Predicted)

storage temp. 

2-8°C

pka

3.74±0.22(Predicted)

Appearance

Light yellow to light brown Solid

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

H332Harmful if inhaled

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

5-Ethynyl-2,2'-bipyridine Chemical Properties,Usage,Production

Synthesis

General procedure for the synthesis of 5-alkynyl-2,2'-bipyridines from 5-trimethylsilylethynyl-2,2'-bipyridines: 5-[(trimethylsilyl)ethynyl]-2,2'-bipyridine (0.360 g, 1.43 mmol) was dissolved in 30 mL of THF (pre-gassed with N2). Subsequently, a methanol (30 mL) solution of KOH (0.320 g, 5.72 mmol) was added. The reaction mixture was stirred at room temperature for 6 hours. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was purified by fast silica gel column chromatography using dichloromethane as eluent. The product yield was 95% (245 mg). Thin layer chromatography (TLC, SiO2) showed an Rf value of 0.45 (10% methanol/dichloromethane). Infrared spectroscopy (IR, KBr, cm-1 ) showed characteristic absorption peaks: 3298 (C≡CH), 3190 (C≡CH), 3049 (Ar-H), 3001 (Ar-H), 2964 (Ar-H), 2933 (Ar-H), 2096 (C≡C).1H NMR (400 MHz, CDCl3) δ 3.29 (s, 1H , C≡CH), 7.26-7.33 (m, 1H, PyH), 7.79-7.84 (m, 1H, PyH), 7.88-7.90 (m, 1H, PyH), 8.37-8.41 (m, 2H, PyH), 8.67-8.69 (m, 1H, PyH), 8.77 (m, 1H, PyH). Mass spectra (MS/EI) showed m/z 180 [M+, 100%], 153 [M+-NCH, 48%], 126 [M+-2(NCH), 9%].

References

[1] Chemical Communications, 2012, vol. 48, # 8, p. 1120 - 1122
[2] Chemical Communications, 2015, vol. 51, # 38, p. 8161 - 8164
[3] Chemistry - A European Journal, 2017, vol. 23, # 50, p. 12162 - 12170
[4] Inorganic Chemistry, 2018, vol. 57, # 7, p. 3602 - 3614
[5] Angewandte Chemie - International Edition, 2002, vol. 41, # 12, p. 2086 - 2089