Carbon Dioxide → Lithium diisopropylamide

Participants

Reaction Steps

LDA was prepared by adding via syringe 1.0 ml nBuLi (1.5 M, hexane) to a solution of 0.162 g (1.6 mmol) of diisopropylamine in 3 ml of abs. THF at −5°. After cooling to −78°, 0.177 g of methoxyacetic acid ethyl ester (1.50 mmol), dissolved in 1 ml of abs. THF, was added and the mixture kept for 15 Min. at that temperature to ensure complete deprotonation. 0.38 g of crude 4-[2-(4-bromomethyl-naphthalen-1-yloxy)-ethyl]-5-methyl-2-phenyl-oxazole (<0.90 mmol, prepared as described above on a 1 mmol scale), dissolved in 6 ml of abs. THF, was then added, followed by 3 ml of DMPU. After stirring for 15 Min. at dry ice temperature and 30 Min. at 0°, the reaction mixture was poured onto crashed ice, extracted twice with AcOEt, washed with water, dried over sodium sulfate, and evaporated to dryness. Twofold flash chromatography (SiO2, hexane/AcOEt=74/26, then 76/24) yielded 0.145 g of the title compound as colorless oil.

Provenance & Evidence