Reaktion #1954379

Reaktionsgleichung

capsaicin

(−)-menthyl chloroformate

triethylamine

→

capsaicin l-menthol

Ausbeute 92.3%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the addition
2. 2
   Waschenwashed with 5% aqueous K2CO3 solution, brine
3. 3
   Trocknendried over MgSO4
4. 4
   Einengenconcentrated to dryness
5. 5
   SonstigeThe obtained crude product
6. 6
   Sonstigewas purified through silica gel column chromatography (30% -50% ethyl acetate in hexane as the eluent)

Vorschrift

To a solution of capsaicin (0.7 g, 2.3 mmol) and (−)-menthyl chloroformate (0.5 g, 2.3 mmol) in anhydrous dichloromethane (10 mL) was added triethylamine (0.45 g, 4.5 mmol) dropwise at ambient temperature. After the addition, the reaction mixture was stirred at ambient temperature for 2 hours. The reaction mixture was diluted with dichloromethane (DCM), washed with 5% aqueous K2CO3 solution, brine, dried over MgSO4, concentrated to dryness. The obtained crude product was purified through silica gel column chromatography (30% -50% ethyl acetate in hexane as the eluent) to give 0.98 g of capsaicin l-menthol mutual prodrug (87% yield) as clear viscous oil. 1H-NMR and 13C-NMR of the obtained capsaicin l-menthol mutual prodrug were consistent with the desired structure (see FIGS. 34, 35). Mass spectral analysis of the product was consistent with the desired structure (FIG. 36).

Quelle