1-((Tert-butyldimethylsilyl)oxy)-2-methylpropan-2-ol → 1-(2-(1-(tert-butyldimethylsilyloxy)-2-methylpropan-2-yloxy)-5-nitrophenyl)-4-methyl-1H-tetrazol-5(4H)-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

1-(Tertbutyldimethylsilyloxy)-2-methylpropan-2-ol (1.80 g, 8.81 mmol, 1.10 equiv) in THF (30 mL) under argon gas, was cooled to −78° C. Potassium tert-butoxide (1.165 g, 9.61 mmol, 1.20 equiv) was added in one portion, and the reaction mixture was stirred for 15 min at −78° C. Then a solution of 1-(2-fluoro-5-nitrophenyl)-4-methyl-1H-tetrazol-5(4H)-one (prepared according to WO2011068898, which is incorporated herein by reference; 1.915 g, 8.00 mmol, 1.00 equiv) in THF (10 mL) was added slowly, and the reaction mixture was stirred for 30 min at −78° C. and allowed to warm up to ambient temperature over 1 h. The reaction mixture was concentrated, and the residue was taken in EtOAc and water. The layers were separated, and the aqueous layer was extracted with EtOAc 2×. The organic layer was dried over Na2SO4, filtered, and concentrated. The crude product was absorbed onto silica gel and purified by flash chromatography and eluted with heptane:EtOAc=100:0 to 30% EtOAc using 10% EtOAc increments to provide 1-(2-(1-(tert-butyldimethylsilyloxy)-2-methylpropan-2-yloxy)-5-nitrophenyl)-4-methyl-1H-tetrazol-5(4H)-one (2.28 g, 67%) as a yellow oil.

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