Diisopropylamine → 4-Methyl-3-(2-pyridyl)phenyl-pent-4-enoic acid

Participants

Reaction Conditions

Reaction Steps

nBuLi (21 ml, 2.5 M in hexanes, 52.16 mmol) was added dropwise to a solution of diisopropyl amine (5.3 ml, 52.5 mmol) in THF (60 ml) at 0 degrees C. The reaction was stirred 20 minutes, then cooled to −78 degrees C. The LDA solution was then added dropwise into a cooled solution of 3-(2-pyridyl)phenyl acetic acid (5.0 g, 23.5 mmol) in THF (20 ml) at −78 degrees C. After addition, the reaction mixture was warmed to 0 degrees C., then cooled again to −78 degrees C. 3-Bromo-2-methylpropene (3.55 ml, 35.2 mmol) was then added rapidly. The reaction mixture was stirred for 1 h. then quenced with water (20 ml). The THF from the reaction mixture was then removed in vacuo, then the pH of the solution was adjusted to 7 by adding con HCl and pH 7 buffer (1 M). The aqueous reaction mixture was then extracted twice with CHCl3. The combined organic extracts were dried with magnesium sulfate, concentrated in vacuo, and chromatographed (silica gel, 3% MeOH-CH2Cl2) to yield a white solid (4.8 g, 77%): MS ES(+) 268.3 (M+H+).

Provenance & Evidence