3,5-Dimethylpyrazole → HCID 4712180, compound

Temperature

0 °C

A mixture of 3,5-dimethyl-1H-pyrazole (Aldrich, 10 g, 104 mmol), K2CO3 (43.1 g, 312 mmol), and ethyl 2-bromoacetate (12.69 mL, 114 mmol) in acetone (100 mL) was refluxed overnight. The salts were removed by filtration and the filtrate was evaporated under reduced pressure. The residue was dissolved in diethyl ether and the organic phase was dried over anhydrous sodium sulfate, filtered and evaporated under reduced pressure. The oily residue was dissolved in hot hexane and the insoluble material was filtered and discarded. The filtrate was cooled at 0° C. and the precipitate obtained was filtered and dried to give the title compound ethyl 2-(3,5-dimethyl-1H-pyrazol-1-yl)acetate (8 g, 43.9 mmol, 42.2% yield) as a gum. 1H NMR: (CDCl3-d6, 300 MHz) δ 5.82 (s, 1H), 4.72 (s, 2H), 4.18 (q, 2H), 2.18 (s, 3H), 2.17 (s, 3H), 1.24 (t, J=7.1 Hz, 3H).

1. temperaturewas refluxed overnight
2. customThe salts were removed by filtration
3. customthe filtrate was evaporated under reduced pressure
4. dissolutionThe residue was dissolved in diethyl ether
5. dry with materialthe organic phase was dried over anhydrous sodium sulfate
6. filtrationfiltered
7. customevaporated under reduced pressure
8. dissolutionThe oily residue was dissolved in hot hexane
9. filtrationthe insoluble material was filtered
10. customthe precipitate obtained
11. filtrationwas filtered
12. customdried

ORD record

ord-6161db985277427ab5312d181509212f

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09061998B2