Hydrochloric Acid → Ethyl 2-(3-chloro-4-fluoro-phenylhydrazino)propionate

温度

0 °C

A mixture of 3-chloro-4-fluoroaniline (10.0 g) in a 6 N aqueous hydrochloric acid solution (35 ml) was cooled to 0° C., and thereto was added dropwise a solution of sodium nitrite (4.80 g) in H2O (6.3 ml). After being stirred at same temperature for 25 minutes, the mixture was added to a solution of ethyl 2-methylacetoacetate (11.0 g), potassium hydroxide (21.2 g) and sodium acetate (21.2 g) in ethyl alcohol (80 ml)-H2O (100 ml) in one portion at 0° C. The resultant mixture was stirred at same temperature for 2 hours, and extracted with diethyl ether. The organic layer was washed with water twice and brine followed by being dried over sodium sulfate. The insoluble materials were filtered off, and the filtrate was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=5:1-3:1) to give ethyl 2-(3-chloro-4-fluoro-phenylhydrazino)propionate (6.16 g) as a reddish solid. APCI-Mass m/Z 259/261 (M+H).

1. extractionextracted with diethyl ether
2. washThe organic layer was washed with water twice
3. dry with materialby being dried over sodium sulfate
4. filtrationThe insoluble materials were filtered off
5. customthe filtrate was evaporated under reduced pressure
6. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=5:1-3:1)

ORDレコード

ord-0a179adff3f141c2962997c3878a5082

出典データセット

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US07935674B2