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ChemicalBook CAS DataBase List Ethanone, 2-bromo-1-(1-methyl-1H-pyrazol-4-yl)- (9CI)
706819-66-1

Ethanone, 2-bromo-1-(1-methyl-1H-pyrazol-4-yl)- (9CI) synthesis

5synthesis methods
-

Yield:706819-66-1 92%

Steps:

P.1.B Step B:

Step B:
2-bromo-1-(1-methyl-1H-pyrazol-4-yl)ethan-1-one
At about 15 °C, to the solution of 1-(1-methyl-1H-pyrazol-4-yl)ethan-1-one (14.4 g, 116 mmol) in DCM (200 mL) and ethanol (50 mL) PyHBr3 (37 g, 116 mmol) was added.
The mixture was stirred at about 15°Cfor about 18 hours.
After the reaction was completed, water (200 mL) was added to stop the reaction.
Then, the aqueous phase was extracted with DCM (4*200 mL).
The combined DCM extracts were dried over anhydrous sodium sulfate and concentrated to remove most of the solvent.
The residue was diluted with petroleum ether followed by being stirred at about 15°C for about 30 minutes, and precipitate was formed.
After filteration, the precipitate was dried to obtain a yellow solid of the title compound (21.5 g, yield 92%)
1H NMR(400MHz, CDCl3) δ 7.97 (s, 1H), 7.91 (s, 1H), 4.17 (s, 2H), 3.93 (s, 3H).
m/z=203[M+1]+.

References:

EP3954689,2022,A1

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