Reaktion #9373

Reaktionsgleichung

HCl

NaH

dimethylcarbonate

5-fluoroindanone

→

5-fluoro-indan-2-carboxylic acid methyl ester

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with Et2O or EtOAc
2. 2
   WaschenThe organic layers were washed with water
3. 3
   Trocknendried over MgSO4
4. 4
   Sonstigeevaporated to dryness
5. 5
   SonstigeThe residue was used in the next step without further purification
6. 6
   workup.DISSOLUTIONThe keto-ester was dissolved in AcOH (100 mL)
7. 7
   workup.ADDITION10% Pd/C (2 g) was added
8. 8
   workup.ADDITIONThe mixture was diluted with Et2O or CHCl3 and water
9. 9
   Filtrationfiltered through a pad of celite
10. 10
    SonstigeThe organic layer was separated
11. 11
    Extraktionthe aqueous layer was extracted with Et2O
12. 12
    Waschenwashed with water
13. 13
    Trocknendried over MgSO4
14. 14
    Filtrationfiltered
15. 15
    Sonstigeevaporated
16. 16
    Sonstigeto leave a residue
17. 17
    SonstigeThe residue was purified by chromatography on silica gel with 15% EtOAc

Vorschrift

To a mixture of NaH (2.64 g, 66 mmol) in dimethylcarbonate (4.2 mL, 50 mmol) in THF (30 mL) was added a solution of 5-fluoroindanone (commercially available from Aldrich) (5 g, 33 mmol). After 30 m at 65° C. the mixture was cooled to rt, acidified with HCl (aq) and extracted with Et2O or EtOAc. The organic layers were washed with water, dried over MgSO4 and evaporated to dryness. The residue was used in the next step without further purification. The keto-ester was dissolved in AcOH (100 mL) and 70% perchloric acid (2 mL). 10% Pd/C (2 g) was added and the mixture was hydrogenated at 50 psi for 18 h. The mixture was diluted with Et2O or CHCl3 and water and filtered through a pad of celite. The organic layer was separated and the aqueous layer was extracted with Et2O. The organic fractions were pooled, washed with water, dried over MgSO4, filtered and evaporated to leave a residue. The residue was purified by chromatography on silica gel with 15% EtOAc: hexane to give 5-fluoro-indan-2-carboxylic acid methyl ester (Intermediate EIGHTEEN-3), 2.25 g. Use of 5-fluoro-indan-2-carboxylic acid methyl ester (Intermediate EIGHTEEN-3) in Method SEVENTEEN produced 4-(5-fluoro-indan-2-yl)-1,3-dihydro-imidazole-2-thione (Compound 145).

Quelle