Diisopropylethylamine → 1-(3-Cyclopropyl-propionyl)-4-(2-methoxy-ethyl)-piperidine-4-carboxylic acid ethyl ester

Participants

Reaction Steps

To a solution of 3-cyclopropyl-propionic acid (0.342 g) in acetronitril (15 ml) were added under an argon atmosphere N-ethyldiisopropylamine (0.775 g, 1.03 ml) and BOP (1.328 g and the mixture was stirred for 50 minutes at RT. Then 4-(2-methoxy-ethyl)-piperidine-4-carboxylic acid ethyl ester (0.646 g) were added and the mixture was stirred for 12 h at RT. The reaction mixture was 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-(3-cyclopropyl-propionyl)-4-(2-methoxy-ethyl)-piperidine-4-carboxylic acid ethyl ester, (0.34 g) as a yellow oil that was used in the next step without further purification.

Provenance & Evidence