Reacción #1954379

Ecuación de reacción

capsaicin

(−)-menthyl chloroformate

triethylamine

→

capsaicin l-menthol

Rendimiento 92.3%

Disolventes

dichloromethane

dichloromethane

Condiciones de reacción

Tratamiento posterior

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

Procedimiento

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).

Fuente