Reaktion #166191

Reaktionsgleichung

DMF

2-bromo-4-fluoro-benzoic acid tert-butyl ester

lithium diisopropylamide

→

title compound

Ausbeute 62.0%

2-Bromo-4-fluoro-3-formyl-benzoic acid tert-butyl ester

Ausbeute 62.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthen stirred for a further 10 minutes
2. 2
   Sonstigebefore quenching with acetic acid (3 mL)
3. 3
   SonstigeThe products were partitioned between ethyl acetate and water
4. 4
   Sonstigethe organic layer was separated
5. 5
   Waschenwashed with brine
6. 6
   Trocknendried (Na2SO4)
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated in vacuo
9. 9
   Sonstigeto give a yellow oil which
10. 10
    Sonstigecrystallized
11. 11
    SonstigeThe crude product was triturated in cyclohexane

Vorschrift

To a solution of 2-bromo-4-fluoro-benzoic acid tert-butyl ester (10.0 g, 36 mmol) in THF (100 mL) at −78° C. under an atmosphere of nitrogen was added lithium diisopropylamide (1.8M solution, 20 mL, 36 mmol) dropwise. The reaction mixture was stirred for 1.25 hours before adding DMF (10 mL) then stirred for a further 10 minutes before quenching with acetic acid (3 mL). The products were partitioned between ethyl acetate and water, the organic layer was separated, washed with brine, dried (Na2SO4), filtered and concentrated in vacuo to give a yellow oil which crystallized on standing. The crude product was triturated in cyclohexane to give the title compound as a yellow solid (6.8 g, 62%). 1H NMR (CDCl3, 400 MHz) 10.38 (1H, s), 7.80-7.73 (1H, m), 7.17 (1H, t, J=9.09 Hz), 1.62 (9H, s).

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