Ethyl chloroformate → HCID 178468922, compound

Temperature

45 °C

3-Isopropyl-1-(2-phenylpropan-2-yl)-1H-pyrazol-5(4H)-one (1.22 g, 5.00 mmol) and calcium hydroxide (435 mg, 7.50 mmol) were suspended in dioxane (20 mL), heated to 45° C. and stirred for 1 hour. After the stirring, the reaction solution was allowed to cool to room temperature, and after dropwise addition of ethyl chloroformate (597 mg, 5.50 mmol), stirred at 90° C. for 6 hours. After completion of the reaction, the resulting light brown suspension was poured into ice-cold 3 M hydrochloric acid and extracted with chloroform (20 mL×5). The resulting organic layer was washed with 0.06 M hydrochloric acid (50 mL×2), dried over anhydrous sodium sulfate and filtered, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by intermediate pressure silica gel column chromatography (silica gel 40 g, ethyl acetate:hexane=1:19 to 1:9) to give 650 mg of the desired product as a yellow oil.

1. temperatureto cool to room temperature
2. stirringstirred at 90° C. for 6 hours
3. customAfter completion of the reaction
4. extractionextracted with chloroform (20 mL×5)
5. washThe resulting organic layer was washed with 0.06 M hydrochloric acid (50 mL×2)
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationthe filtrate was concentrated under reduced pressure
9. customThe resulting residue was purified by intermediate pressure silica gel column chromatography (silica gel 40 g, ethyl acetate:hexane=1:19 to 1:9)

ORD record

ord-8cd2b454be56465b82836f34028983e3

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09212348B2