Реакция #2146786

Уравнение реакции

4-iodo-1-trityl-1H-imidazole

2-methyl-but-3-yn-2-ol

potassium hydroxide

→

product

Выход 41.0%

4-Ethynyl-1-trityl-1H-imidazole

Выход 41.0%

Растворители

isopropanol

THF

triethylamine

Условия реакции

Обработка

1. 1
   Другоеthe reaction vessel was evacuated
2. 2
   Другоеto remove atmospheric oxygen
3. 3
   workup.ADDITIONCopper (I) iodide (40 mg, 10 mol %) was added
4. 4
   ДругоеAfter this time the solvent was removed under vacuum
5. 5
   Фильтрацияthe residue was filtered through a plug of silica gel (eluent=2:1 hexane:ethyl acetate)
6. 6
   Другоеto give the crude alkynol product
7. 7
   ТемператураThe reaction mixture was heated to 70° C. for 4 h
8. 8
   Концентрированиеconcentrated under vacuum
9. 9
   Другоеpurified by silica-gel chromatography (eluent=4:1 hexane:ethyl acetate)

Методика

To a stirred solution of 4-iodo-1-trityl-1H-imidazole (830 mg, 1.96 mmol) and Pd(Ph3P)2Cl2 (40 mg, 3 mol %) in THF (8 mL) and triethylamine (2 mL) was added 2-methyl-but-3-yn-2-ol (0.30 mL, 3.10 mmol) and the reaction vessel was evacuated and backfilled with nitrogen three times to remove atmospheric oxygen. Copper (I) iodide (40 mg, 10 mol %) was added and the reaction was stirred at room temperature for 5 h. After this time the solvent was removed under vacuum and the residue was filtered through a plug of silica gel (eluent=2:1 hexane:ethyl acetate) to give the crude alkynol product. This material was dissolved in isopropanol (10 mL) and treated with potassium hydroxide (150 mg, 2.67 mmol). The reaction mixture was heated to 70° C. for 4 h and then concentrated under vacuum and purified by silica-gel chromatography (eluent=4:1 hexane:ethyl acetate) to afford the product as a white solid (258 mg, 41% yield over two steps). 1H-NMR (CDCl3) δ 7.41 (s, 1H), 7.38-7.31 (m, 9H), 7.13-7.07 (m, 6H), 7.05 (d, J=1 Hz), 3.05 (s, 1H).

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