Triethylamine → 1-[3-(2-Phenylpyrazolo[1,5-a]pyridin-3-yl)acryloyl]-2-ethylpiperidine

Isobutyl chloroformate (1.04 g) was added dropwise to a mixture of 3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)acrylic acid (trans isomer) (2.0 g) and triethylamine (0.766 g) in methylene chloride (40 ml) and tetrahydrofuran (10 ml) at -20° C. with stirring. After being stirred at the same temperature for 30 minutes, a solution of 2-ethylpiperidine (0.942 g) in tetrahydrofuran (10 ml) was added thereto dropwise at -20° C. and the mixture was stirred at -20° C. to 10° C. for 2 hours. The mixture was warmed to room temperature and evaporated in vacuo. A saturated sodium bicarbonate solution was added to the residue and extracted twice with chloroform (50 ml). The combined extract was washed with saturated brine (50 ml), dried over magnesium sulfate and evaporated in vacuo. The residue was chromatographed on silica gel (40 g) with chloroform as an eluent. The fractions containing the object compound were combined and evaporated in vacuo to give 1-[3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)acryloyl]-2-ethylpiperidine (trans isomer) (1.30 g) as an oil.

1. stirringAfter being stirred at the same temperature for 30 minutes
2. stirringdropwise at -20° C. and the mixture was stirred at -20° C. to 10° C. for 2 hours
3. customevaporated in vacuo
4. additionA saturated sodium bicarbonate solution was added to the residue
5. extractionextracted twice with chloroform (50 ml)
6. extractionThe combined extract
7. washwas washed with saturated brine (50 ml)
8. dry with materialdried over magnesium sulfate
9. customevaporated in vacuo
10. customThe residue was chromatographed on silica gel (40 g) with chloroform as an eluent
11. additionThe fractions containing the object compound
12. customevaporated in vacuo

ORD record

ord-03883153fa7247be8260b1669ed3fb2e

Source dataset

uspto-grants-1991_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04994453