Category: 2739-98-2

Synthetic Route of 2739-98-2 ,Some common heterocyclic compound, 2739-98-2, molecular formula is C9H11NO2, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route.

2-Hydroxypyrazolo[1,5-a]pyridine (I). After a mixture of ethyl 2-pyridylacetate (3.00 g), HAS (0.60 g) and water (3 ml) was stirred at room temperature for 30 h, it was extracted with CH2 CL2. The aqueous layer was made alkaline with 10% Na2 CO3 to pH 9 and was extracted with CH2 CL2. The organic extracts were combined, and after drying over MgSO4 the solvent was evaporated. The residual oil was shaken with Et2 O-10% Na2 CO3. After the ether-layer was dried over MgSO4, the solvent was evaporated to give the starting ethyl 2-pyridylacetate (2.11 g, 70.5% yield). The pH of the basic aqueous layer was adjusted to 5 by adding AcOH to precipitate brown powder (0.36 g, 45.9% yield, based upon the consumed starting material). Recrystallization from benzene-hexane gave 2-hydroxypyrazolo[1,5-a]pyridine (0.32 g, 40.7%) mp 127-128 C., as colorless leaflets. UV lambdamaxmeOH (log epsilon): 232 (4.59), 280.5 (3.09), 310 (3.10). STR85 3000, 1635, 1535, 1258. Found: C, 62.53; H, 4.48; N, 20.98%. Calcd for C7 H6 ON2: C,62.68; H, 4.51; N, 20.98%.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route,2739-98-2, its application will become more common.

Reference:
Patent; Boehringer Mannheim GmbH; US5334505; (1994); A;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

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

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