In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 2739-98-2, name is Ethyl 2-Pyridylacetate, the common compound, a new synthetic route is introduced below. COA of Formula: C9H11NO2
1b) 2-Hydroxypyrazolo[1,5-a]pyridine (C4f); The synthesis of 2-hydroxypyrazolo[1,5-a]pyridine was done according to literature (Ochi, M.; Miyasaka, T.; Kanada, K.; Arakawa, K. Bull. Chem. Soc. Japan, (1976), 49, 1980-1984).; A solution of 4.14 g (36.6 mmol) hydroxylamine-O-sulfonic acid in 13.8 ml water was neutralized with KOH (2.6 N) at 0C and added dropwise to 26.2 ml (0.172 mol) ethyl 2-pyridylacetate. After stirring for 30 h at room temperature the mixture was extracted with dichloromethane, the aqueous layer was adjusted to pH 9 with Na2CO3 solution (10%) and extracted with dichloromethane. Then, the aqueous layer was adjusted to pH 5 with acetic acid, extracted with dichloromethane, the organic layer was dried with MgSO4 and evaporated. The crude product was purified by flash-chromatography (hexane/EtOAc 90:10). Yield: 607 mg (39 %) white solid. Mp.: 127-128C. MS (APCI): m/z 135 (M+1)+. 1H NMR (DMSO-d6, 360 MHz) delta (ppm): 5.72 (d, J = 0.8 Hz, 1 H, H-3); 6.63 (ddd, J = 6.8 Hz, 6.8 Hz, 1.4 Hz, 1 H, H-6); 7.08 (ddd, J = 8.9 Hz, 6.8 Hz, 1.1 Hz, 1 H, H-5); 7.35 (ddd, J = 8.9 Hz, 1.4 Hz, 0.8 Hz, 1 H, H-4); 8.32 (dd, J = 6.8 Hz, 1.1 Hz, 1 H, H-7); 10.40 (s, 1 H, OH).
The synthetic route of 2739-98-2 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; SCHWARZ PHARMA AG; EP1972628; (2008); A1;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem