Reaktion #574813

Reaktionsgleichung

trans-3-hydroxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-5-t-butyldimethylsilyloxymethyl-1-pyridinyl)-2H-benzo[b]pyran

sodium hydride

→

6-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-5-t-butyldimethylsilyloxymethyl-1-pyridinyl}-2H-benzo[b]pyran

Ausbeute 91.6%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigereacted
2. 2
   Temperaturunder reflux for 3 hours
3. 3
   EinengenThe reaction mixture is concentrated under reduced pressure
4. 4
   workup.ADDITIONthe residue is mixed with ethyl acetate and water
5. 5
   Extraktionextracted with the ethyl acetate
6. 6
   WaschenThe organic layer is successively washed with water and saturated aqueous solution of sodium chloride
7. 7
   Trocknendried over anhydrous sodium sulfate
8. 8
   FiltrationThe inorganic matter is filtered off
9. 9
   Einengenthe filtrate is concentrated under reduced pressure
10. 10
    SonstigeThe residue is purified by silica gel column chromatography
11. 11
    workup.ADDITION1/3 mixture of ethyl acetate/methylene chloride as a developing solvent

Vorschrift

In 50 ml of anhydrous tetrahydrofuran, is dissolved 1.32 g of trans-3-hydroxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-5-t-butyldimethylsilyloxymethyl-1-pyridinyl)-2H-benzo[b]pyran obtained in Example 12. Then, 0.12 g of 60% oily sodium hydride is added to the solution at room temperature, and reacted under reflux for 3 hours. The reaction mixture is concentrated under reduced pressure, and the residue is mixed with ethyl acetate and water and extracted with the ethyl acetate. The organic layer is successively washed with water and saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. The inorganic matter is filtered off, and the filtrate is concentrated under reduced pressure. The residue is purified by silica gel column chromatography using 1/3 mixture of ethyl acetate/methylene chloride as a developing solvent to obtain 1.16 g of 6-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-5-t-butyldimethylsilyloxymethyl-1-pyridinyl}-2H-benzo[b]pyran.

Quelle