Water → Methyl 5-(1,3-dioxolan-2-yl)-1-benzofuran-2-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

5-[1,3]Dioxolan-2-yl-benzofuran (50 mg, 0.26 mmol) was dissolved in THF (2 mL) and the solution was cooled down to −78° C. Butyl lithium (180 uL, 1.1 eq.) was added dropwise. This mixture was stirred 30 min at 25° C. Then the reaction mixture was cooled down to −78° C. and methyl cyanoformate (23 uL, 1.1 eq.) dissolved in 1 mL THF was added dropwise to the reaction mixture. After 1 h30 only small amount of starting material was detected and two major compounds were formed (expected product/dimer 73:27). The temperature was increased slowly to room temperature overnight. Water and ethyl acetate were added to the mixture and the aqueous layer was extracted 3 times. Combined organic phases was dried over MgSO4, filtrated and evaporated to give the 5-[1,3]Dioxolan-2-yl-benzofuran-2-carboxylic acid methyl ester (31.9 mg, 44%) mixed with the dimer (expected product/dimer 46:54). The mixture was used directly in the next step.

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