Reaktion #88423

Reaktionsgleichung

(E)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

tripotassium phosphate

2-dicyclohexylphosphino-2′,6′-dimethoxy-1,1′-biphenyl

methyl 4-(5-bromo-4-methylthiazol-2-yl)-1-methyl-1H-pyrazole-5-carboxylate

sodium hydrogen carbonate

→

title compound

Ausbeute 63.8%

(E)-methyl 4-(5-(2-ethoxyvinyl)-4-methylthiazol-2-yl)-1-methyl-1H-pyrazole-5-carboxylate

Ausbeute 63.8%

Lösungsmittel

acetonitrile

water

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeobtained in (Example 5.11) <Step 1>
2. 2
   ExtraktionAfter extraction of organic layers, water layers
3. 3
   Extraktionwere extracted with ethyl acetate (50 ml)
4. 4
   WaschenThe combined organic layer was washed with a saturated saline
5. 5
   Trocknenwas then dried over anhydrous sodium sulfate
6. 6
   workup.DISTILLATIONThe solvent was distilled away under reduced pressure
7. 7
   Sonstigethe obtained residue was then purified by silica gel column chromatography (silica gel: eluent; heptane:ethyl acetate=92:8-40:60)

Vorschrift

(E)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (63 mg), palladium acetate (7.1 mg), tripotassium phosphate (67 mg), 2-dicyclohexylphosphino-2′,6′-dimethoxy-1,1′-biphenyl (26 mg), and water (0.35 ml) were added to an acetonitrile (4.0 ml) solution of the methyl 4-(5-bromo-4-methylthiazol-2-yl)-1-methyl-1H-pyrazole-5-carboxylate (50 mg) obtained in (Example 5.11) <Step 1>, and the obtained mixture was then stirred under heating in a nitrogen atmosphere for 2 hours at 90° C. Thereafter, ethyl acetate (50 ml) and a saturated sodium hydrogen carbonate aqueous solution (30 ml) were added to the reaction solution. After extraction of organic layers, water layers were extracted with ethyl acetate (50 ml). The organic layers were combined. The combined organic layer was washed with a saturated saline, and was then dried over anhydrous sodium sulfate. The solvent was distilled away under reduced pressure, and the obtained residue was then purified by silica gel column chromatography (silica gel: eluent; heptane:ethyl acetate=92:8-40:60), so as to obtain the title compound (31 mg) in the form of a yellow solid.

Quelle