4-Methoxy cinnamic acid → (S)-Benzyl N-(4-Methoxycinnamoyl)pipecolate

Beteiligte Stoffe

Reaktionsschritte

To a solution of 145 mg (0.37 mmol) of (S)-Benzyl pipecolate salt (14) (described in Example 1) in 8.0 mL of methylene chloride was added 102 mg (0.57 mmol) of 4-methoxycinnamic acid, 107 mg (0.55 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and 130 μL (0.74 mmol) of diisopropylethylamine. The resulting solution was stirred at ambient temperature for 12 h and was then concentrated under reduced pressure. Flash chromatography (elution with 1:1 ethyl acetate-hexane) gave 91 mg (65%) of the amide (8) as a colorless oil. 1H NMR (300 MHz, CDCl3) δ 7.66 (d), 7.50 (d), 7.35 (m), 6.90 (d), 6.82 (d), 6.63 (d), 5.55 (d), 5.20 (br s), 4.86 (br s), 4.67 (br d) 4.03 (br d), 3.83 (s), 3.37 (dt), 2.78 (dt) 2.33 (br d), 1.74 (m), 1.43 (m), Rf 0.40 (1:1 ether-hexane).

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