[H-].[Na+].I[CH2:4][CH2:5][CH3:6].[Si:7]([O:14][CH2:15][C:16]1[N:20]=[CH:19][NH:18][N:17]=1)([C:10]([CH3:13])([CH3:12])[CH3:11])([CH3:9])[CH3:8].O>CN(C=O)C>[Si:7]([O:14][CH2:15][C:16]1[N:17]([CH2:4][CH2:5][CH3:6])[N:18]=[CH:19][N:20]=1)([C:10]([CH3:13])([CH3:11])[CH3:12])([CH3:9])[CH3:8].[Si:7]([O:14][CH2:15][C:16]1[N:20]=[CH:19][N:18]([CH2:4][CH2:5][CH3:6])[N:17]=1)([C:10]([CH3:13])([CH3:11])[CH3:12])([CH3:9])[CH3:8]To a stirred mixture of sodium hydride (60% dispersion in oil, 1.5 g, 37.5 mmol) and 1-iodopropane (4.4 ml, 45 mmol) in anhydrous DMF (100 ml), cooled under nitrogen to 0° C., was added dropwise over 10 min a solution of 3-(tert-butyldimethylsilanyloxymethyl)-1H-1,2,4-triazole (prepared as described in EP-A-421210) (8.0 g, 37.5 mmol) in anhydrous DMF (25 ml). The mixture was stirred under nitrogen at 0° C. for 25 min, more sodium hydride (60% dispersion in oil, 0.45 g, 11.3 mmol) was added, and the mixture was stirred for another 30 min. Water (300 ml) was then added and the mixture was extracted with ethyl acetate (3×100 ml). The combined organic extracts were washed with brine (100 ml), dried (Na2SO4) and evaporated in vacuo. The residue was purified by flash chromatography (silica gel, 40-50% EtOAc/hexane; and alumina, 15% EtOAc/hexane) to yield 4.10 g (43%) of 5-(tert-butyldimethylsilanyloxymethyl)-1-propyl-1H-1,2,4-triazole and 2.97 g (31%) of 3-(tert-butyldimethylsilanyloxymethyl)-1-propyl-1H-1,2,4-triazole as colourless oils.
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