Реакция #2146779

Уравнение реакции

4-iodo-1-(4-methoxy-benzyl)-1H-pyrazole

trimethylsilylacetylene

methanol

potassium hydroxide

→

title compound

Выход 81.5%

4-Ethynyl-1-(4-methoxy-benzyl)-1H-pyrazole

Выход 81.5%

Растворители

DCM

triethylamine

Условия реакции

Обработка

1. 1
   Другоеwas evacuated
2. 2
   ДругоеThe reaction rapidly became dark
3. 3
   Другоеwere removed in vacuo
4. 4
   workup.STIRRINGAfter stirring for 30 minutes the mixture
5. 5
   Концентрированиеwas concentrated onto silica gel
6. 6
   Другоеpurified by flash column chromatography (eluent—hexane:diethyl ether 2:1)

Методика

A vigorously stirred solution of 4-iodo-1-(4-methoxy-benzyl)-1H-pyrazole (1.0 g, 3.18 mmol) and Pd(Ph3P)2Cl2 (60 mg, 3 mol %) in a mixture of DCM (10 mL) and triethylamine (3 mL) was evacuated and backfilled with nitrogen three times and then treated sequentially with trimethylsilylacetylene (0.53 mL, 3.83 mmol) and copper (I) iodide (70 mg, 12 mol %). The reaction rapidly became dark and after stirring for 3 h the solvents were removed in vacuo and the residue treated with methanol (10 mL) and potassium hydroxide (300 mg, 5.35 mmol). After stirring for 30 minutes the mixture was concentrated onto silica gel and purified by flash column chromatography (eluent—hexane:diethyl ether 2:1) to afford the title compound as a white solid (550 mg, 81% yield over two steps). 1H-NMR (CDCl3) δ 7.61 (s, 1H), 7.46 (s, 1H), 7.17 (d, J=8.6 Hz, 2H), 6.86 (d, J=8.6 Hz, 2H), 5.18 (s, 2H), 3.78 (s, 3H), 2.96 (s, 1H).

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