Réaction #2122492

Équation de réaction

3-[1-Methoxy-4-(4-methoxy-benzylsulfanyl)-piperidin-4-yl]-3-oxo-2-(2,4,6-trimethylphenyl)-propionic acid methyl ester

3-[1-methoxy-4-(4-methoxy-benzylsulfanyl)-piperidin-4-yl]-3-oxo-2-(2,4,6-trimethylphenyl)-propionic acid methyl ester

sodium hydroxide

→

4-hydroxy-8-methoxy-3-(2,4,6-trimethyl-phenyl)-1-thia-8-aza-spiro[4.5]dec-3-en-2-one

Rendement 48.3%

Solvants

water

trifluoroacetic acid

Conditions de réaction

Traitement

1. 1
   Températureheated
2. 2
   Températureon reflux for 18 hours
3. 3
   Extractionextracted with t-butylmethyl ether
4. 4
   SéchageThe organic layer was dried over anhydrous sodium sulfate
5. 5
   Autrethe solvent evaporated
6. 6
   AutreThe residue was chromatographed on silica gel with ethyl acetate/cyclohexane (1:1

Mode opératoire

470 mg 3-[1-Methoxy-4-(4-methoxy-benzylsulfanyl)-piperidin-4-yl]-3-oxo-2-(2,4,6-trimethylphenyl)-propionic acid methyl ester (from Step 6) was dissolved in 15 ml trifluoroacetic acid and heated on reflux for 18 hours. The mixture was cooled to room temperature, diluted with water, the pH adjusted to 4.2 by the addition of aqueous sodium hydroxide, then extracted with t-butylmethyl ether. The organic layer was dried over anhydrous sodium sulfate, and the solvent evaporated. The residue was chromatographed on silica gel with ethyl acetate/cyclohexane (1:1, then 2:1) as a solvent, to yield 156 mg 4-hydroxy-8-methoxy-3-(2,4,6-trimethyl-phenyl)-1-thia-8-aza-spiro[4.5]dec-3-en-2-one (compound P2.4) as a solid, mp 67-71° C.

Source