Ethylene Glycol → 2-Bromo-5-(2-methyl-[1,3]dioxolan-2-yl)-thiazole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a flame dried round-bottomed flask equipped with a magnetic stir bar and a condenser under inert atmosphere (N2), a solution of 1-(2-bromo-thiazol-5-yl)-ethanone (2.20 g, 10.68 mmol) in ethylene glycol (11.46 mL, 205.53 mmol) was treated with trimethylorthoformate (2.39 mL, 21.76 mmol) followed by LiBF4 (204 mg, 2.14 mmol). The reaction mixture was heated at 95° C. for 2 days. Sat. aq. NaHCO3 (50 mL) was added and the mixture was extracted with EA (50 mL). The org. extracts were washed with brine (2×50 mL), dried over MgSO4, filtered, and the solvent was removed under reduced pressure. Purification of the residue by FC (20:1 to 3:1 hept-EA) gave the title compound as a yellow oil. TLC:rf (1:1 hept-EA)=0.80. LC-MS-conditions 01: tR=0.84 min; [M+H]+=251.85.

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