1-Propanone,1-[1-[(4-Methoxyphenyl)Methyl]-1H-pyrazol-4-yl]- synthesis

Yield:1105039-60-8 97%

Reaction Conditions:

in tetrahydrofuran at 20 - 50; for 3.5 h;

Steps:

5

l-(l-(4-Methoxybenzyl)-lH-pyrazol-4-yl)propan-l-oneAccording to Scheme 3 Step 2: Ethylmagnesium bromide (3ν, 37.2 mmol, 12.4 mL) was added dropwise at room temperature to a solution of N-methoxy- 1 -(4- methoxybenzyl)-N-methyl-lH-pyrazole-4-carboxamide (33.8 mmol, 9.30 g) in TηF (80 mL) and the reaction mixture was stirred for 1 hour. Then ethylmagnesium bromide (3N, 37.2 mmol, 12.4 mL) was added and the reaction mixture was stirred for 1 hour. Finally some more ethylmagnesium bromide (3N, 74.4 mmol, 24.8 mL) was added and the reaction mixture was stirred for 1.5 hour at 50⁰C. The reaction was quenched with HCl (1 N, 300 mL) and the aqueous phase was extracted with DCM. The organic phase was dried over MgSO/t, was filtered and was concentrated to yield l-(l-(4- methoxybenzyl)-lH-pyrazol-4-yl)propan-l-one (32.7 mmol, 8.00 g, 97%) as a yellow oil.LC (Zorbax SB-Ci₈, 3.5μm, 4.6x50mm Column): RT = 2.04 min; MS m/z ES⁺= 245.

References:

WO2009/10455,2009,A2 Location in patent:Page/Page column 53-54