Hydrochloric Acid → 3-(5-Fluoro-pyridin-2-yl)-isoxazole-4-carboxylic acid ethyl ester

温度

60 °C

To a solution of N-chlorosuccinimide (17.34 g, 130 mmol) in DMF (128 mL) was added 5-fluoro-pyridine-2-carbaldehyde oxime (18.2 g, 130 mmol) portionwise over 2 h at room temperature and as the reaction warmed up to 60° C. the mixture was cooled back to room temperature with an ice-water bath and the resulting mixture was then stirred for 64 h at room temperature. To this solution was then added ethyl 3-(N,N-dimethylamino)acrylate (18.6 g, 130 mmol) and triethylamine (36.2 mL, 260 mmol) in chloroform (64 mL) and the resulting mixture was then stirred for 1 h at room temperature and poured onto a mixture of ice water and HCl (4 N, 1 L) and extracted with ethylacetate. The organic extract was then washed with water, saturated aqueous sodium hydrogen carbonate solution, brine, dried with sodium sulfate, filtered and evaporated. Purification by chromatography (SiO2, heptane:ethylacetate=100:0 to 1:1) afforded the title product (21.96 g, 72%) which was obtained as a yellow solid. MS: m/e=237.1 [M+H]+.

1. temperaturewas cooled back to room temperature with an ice-water bath
2. extractionextracted with ethylacetate
3. extractionThe organic extract
4. washwas then washed with water, saturated aqueous sodium hydrogen carbonate solution, brine
5. dry with materialdried with sodium sulfate
6. filtrationfiltered
7. customevaporated
8. customPurification by chromatography (SiO2, heptane:ethylacetate=100:0 to 1:1)

ORDレコード

ord-2681dd3e508647f09aa662550c4cca41

出典データセット

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08846719B2