Tetrahydrofuran → 5,5-Dimethoxy-1-(4,4,5,5,5-pentafluoropentylthio)pentane

To a suspension of LAH (0.4 g, 11 mmol) in tetrahydrofuran (20 ml) was added dropwise at 0° C. methyl 5,5-dimethoxyvalerate (3.5 g, 20 mmol) dissolved in tetrahydrofuran (30 ml), which was then stirred for 2 hours. After the reaction was completed, the mixture was poured into ice-water (50 ml) and then extracted with ether. The organic layer was dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to give a crude product. This crude product thus obtained was subjected to silica gel column chromatography (n-hexane:ethyl acetate-2:1) to give 5,5-dimethoxypentanol (1.02 g, yield 34%). Methanesulfonylchloride (3.2 g, 28 mmol) and triethylamine (3.0 g, 30 mmol) dissolved in dichloromethane (50 ml) were added thereto, and the mixture was stirred at room temperature for 1 hour. After the reaction was completed, the reaction mixture was poured into water and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to give a crude product (2.36 g). While, 4,4,5,5,5-pentafluoropentyl thioacetate (5.7 g, 24 mmol) prepared in Step 1 was dissolved in methanol (10 ml), sodium methoxide (23 mg, 23 mmol, 11.0 mol/l) was added thereto, and the resulting mixture was stirred at room temperature for 1 hour. To this solution was added dropwise the crude product prepared above (0.90 g) dissolved in tetrahydrofuran (10 ml), which was then stirred at room temperature for 5 hours. After the reaction was completed, the reaction mixture was poured into water and extracted with ether. The organic layer was dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to give a crude product. This crude product thus obtained was subjected to silica gel column chromatography (n-hexane:ethyl acetate=20:1) to give 5,5-dimethoxy-1-(4,4,5,5,5-pentafluoropentylthio)pentane (460 mg).

1. additionwere added
2. extractionextracted with chloroform
3. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
4. concentrationconcentrated under reduced pressure
5. customto give a crude product (2.36 g)
6. stirringthe resulting mixture was stirred at room temperature for 1 hour
7. customprepared above (0.90 g)
8. stirringwhich was then stirred at room temperature for 5 hours
9. extractionextracted with ether
10. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
11. concentrationconcentrated under reduced pressure
12. customto give a crude product
13. customThis crude product thus obtained

ORD-Eintrag

ord-5dc346235e4345b39b8312b2a2ad076c

Quelldatensatz

uspto-grants-2006_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07074819B2