Toluene → Pyrazolo[1,5-a]pyridine-3-carbonyl chloride

Pyrazolo[1,5-a]pyridine-3-carboxylic acid (9.72 g) was dissolved in hot anhydrous methanol (225 ml) and treated with a solution of potassium hydroxide (3.73 g) in dry methanol (45 ml) with stirring. The resulting orange solution was evaporated to dryness under reduced pressure, to give a colourless solid. This solid was treated with dry toluene (300 ml) and the mixture was stirred and treated with oxalyl chloride (10.2 ml), with stirring, at room temperature. After further stirring for a period of 15 minutes the mixture was treated with pyridine (45 drops), and the mixture was vigorously stirred overnight. The mixture was then filtered and the filtrate was evaporated under reduced pressure, to give pyrazolo[1,5-a]pyridine-3-carbonyl chloride (10.6 g), m.p. 119°-120° C. (in a sealed tube).

1. customThe resulting orange solution was evaporated to dryness under reduced pressure
2. customto give a colourless solid
3. stirringthe mixture was stirred
4. stirringwith stirring, at room temperature
5. stirringAfter further stirring for a period of 15 minutes the mixture
6. filtrationThe mixture was then filtered
7. customthe filtrate was evaporated under reduced pressure

ORD record

ord-d1d56472d1ba421ab6876b143913b0c4

Source dataset

uspto-grants-1986_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04604400