Reaktion #69204

Reaktionsgleichung

Sodium hydride

4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

DMF

[β-(Trimethylsilyl)ethoxy]methyl chloride

→

4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-[2-(trimethylsilyl)ethoxy]methyl-1H-pyrazole

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   SonstigeThe reaction was partitioned between water and ethyl acetate
3. 3
   WaschenThe organic layer was washed with brine
4. 4
   Trocknendried over MgSO4
5. 5
   Einengenconcentrated

Vorschrift

A solution of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (2.0 g, 0.010 mol) and DMF (30.0 mL, 0.387 mol) was cooled to 0° C. Sodium hydride (320 mg, 0.013 mol) (60% in oil) was added and the mixture was stirred for 10 min. [β-(Trimethylsilyl)ethoxy]methyl chloride (2.4 mL, 0.013 mol) was added and the resulting mixture was stirred for 20 min at 0° C. and 2 h at room temperature. The reaction was partitioned between water and ethyl acetate. The organic layer was washed with brine, dried over MgSO4 and concentrated to give 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-[2-(trimethylsilyl)ethoxy]methyl-1H-pyrazole as a crude material. LC/MS (M+H)+: 325, 1H NMR (CDCl3) δ 7.85 (s, 1H), 7.80(s, 1H), 5.45(s, 2H), 3.55(t, 2H), 1.35(s, 12H), 0.95(t, 2H), 0.0(s, 9H).

Quelle