Oxazolo[4,5-b]pyridine

Oxazolo[4,5-b]pyridine Property

Melting point:

69-72 °C

Boiling point:

199.2±13.0 °C(Predicted)

Density 

1.294±0.06 g/cm3(Predicted)

storage temp. 

2-8°C

form 

solid

pka

-0.27±0.40(Predicted)

color 

Brown

Safety

HS Code 

2934999090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

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

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

Oxazolo[4,5-b]pyridine Chemical Properties,Usage,Production

Definition

ChEBI: Oxazolo[4,5-b]pyridine is a mancude organic heterobicyclic parent and an oxazolopyridine.

Synthesis

General procedure for the synthesis of oxazolo[4,5-b]pyridines from 2-amino-3-hydroxypyridine (90.1 mmol) and triethyl orthoformate (720.7 mmol): 2-amino-3-hydroxypyridine was dissolved in triethyl orthoformate under nitrogen protection, and p-toluenesulfonic acid (4.50 mmol) was added as catalyst. The reaction mixture was stirred at 160 °C overnight. Upon completion of the reaction, the excess of triethyl orthoformate was removed by distillation under reduced pressure. The crude product was purified by column chromatography with the eluent cyclohexane/ethyl acetate (5%-40% gradient elution) to afford oxazolo[4,5-b]pyridine as a beige solid in 68% yield. The product was detected by mass spectrometry (LRMS) with [M + H]+ m/z of 121.1; 1H NMR (DMSO-d6, 400 MHz) δ 9.04 (s, 1H), 8.58 (dd, J = 4.8, 1.4 Hz, 1H), 8.26 (dd, J = 8.2, 1.4 Hz, 1H), 7.50 (dd, J = 8.2, 4.8 Hz , 1H), 6.41 (s, 2H); 13C NMR (DMSO-d6, 101 MHz) δ 157.7, 154.5, 147.1, 142.0, 121.5, 120.1.

References

[1] Monatshefte fur Chemie, 2011, vol. 142, # 1, p. 87 - 91
[2] Journal of Organic Chemistry, 2011, vol. 76, # 13, p. 5444 - 5449
[3] European Journal of Medicinal Chemistry, 2013, vol. 66, p. 450 - 465
[4] Tetrahedron Letters, 1990, vol. 31, # 8, p. 1155 - 1156
[5] Synthetic Communications, 1992, vol. 22, # 20, p. 2891 - 2901