Reaktion #356219

Reaktionsgleichung

HCl

4-bromo-6-trifluoromethyl-pyran-2-one

4-Bromo-6-trifluoromethyl-pyran-2-one

4-iodobenzotrifluoride

isopropylmagnesium chloride

→

solid

Ausbeute 100.6%

6-Trifluoromethyl-4-(4-trifluoromethyl-phenyl)-pyran-2-one

Ausbeute 100.6%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe internal temperature below −65° C.
2. 2
   Sonstigethe cooling bath was removed
3. 3
   Sonstigeto reach 23° C.
4. 4
   workup.STIRRINGstirred at 23° C. for 35 min
5. 5
   Sonstigewere added at 23° C.
6. 6
   workup.STIRRINGstirring
7. 7
   workup.WAITwas continued at 23° C. for 30 min
8. 8
   Sonstige[slightly exothermic reaction
9. 9
   Sonstigerose to 45° C.
10. 10
    Extraktionextracted with EtOAc
11. 11
    Waschenwashed with sat. NaHCO3-sol
12. 12
    Trocknenand brine, dried over Na2SO4
13. 13
    Sonstigeevaporated
14. 14
    Sonstigedried at HV

Vorschrift

To a solution of commercially available 4-iodobenzotrifluoride (1.36 g, 5.00 mmol) in THF (13 mL) at −78° C. was added isopropylmagnesium chloride (2 M in THF, 2.63 mL, 5.25 mmol) within 2 min keeping the internal temperature below −65° C., stirring was continued at −78 to −20° C. for 60 min. ZnCl2 (1 M in THF, 5.50 mL, 5.50 mmol) was added, the cooling bath was removed, the mixture was allowed to reach 23° C. and stirred at 23° C. for 35 min. Pd(PPh3)4 (58 mg, 1 mol %) and 4-bromo-6-trifluoromethyl-pyran-2-one (example C.22 step 3) (1.22 g, 5.00 mmol) were added at 23° C. and stirring was continued at 23° C. for 30 min [slightly exothermic reaction; internal temperature rose to 45° C.]. Poured into icecold 0.5 M HCl, extracted with EtOAc, washed with sat. NaHCO3-sol. and brine, dried over Na2SO4, evaporated and dried at HV to give an orange solid (1.55 g), which was purified by MPLC to give the title compound as a yellow solid (1.27 g, 82%). MS (EI) [(M)t]; mp 52° C.

Quelle