4,4-Dimethylpentanoic acid → 1-(4,4-Dimethyl-pentanoyl)-4-(2-methoxy-ethyl)-piperidine-4-carboxylic acid ethyl ester

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Reaction Steps

To a solution of 4,4-dimethyl-pentanoic acid (0.351 g) in acetronitril (15 ml) were added under an argon atmosphere N-ethyldiisopropylamin (0.7 g, 0.96 ml) and BOP (1.195 g) and the mixture was stirred for 50 minutes at RT. Then 4-(2-methoxy-ethyl)-piperidine-4-carboxylic acid ethyl ester (0.581 g) was added and the mixture was stirred for further 12 h at RT. The reaction mixture was then partitioned between ethyl acetate and aqueous 1M HCl, the layers were separated and the aqueous layer washed with 2M aqueous KHCO3 then dried over Na2SO4. The solvent was evaporated off, the residue purified by flash chromatography (methylene chloride/AcOEt, gradient from 0 to 30%) to give 1-(4,4-dimethyl-pentanoyl)-4-(2-methoxy-ethyl)-piperidine-4-carboxylic acid ethyl ester (0.466 g) as a yellow semi-solid that was used in the next step without further purification.

Provenance & Evidence