Reacción #166191

Ecuación de reacción

DMF

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

lithium diisopropylamide

→

title compound

Rendimiento 62.0%

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

Rendimiento 62.0%

Disolventes

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGthen stirred for a further 10 minutes
2. 2
   Otrobefore quenching with acetic acid (3 mL)
3. 3
   OtroThe products were partitioned between ethyl acetate and water
4. 4
   Otrothe organic layer was separated
5. 5
   Lavadowashed with brine
6. 6
   Secadodried (Na2SO4)
7. 7
   Filtraciónfiltered
8. 8
   Concentraciónconcentrated in vacuo
9. 9
   Otroto give a yellow oil which
10. 10
    Otrocrystallized
11. 11
    OtroThe crude product was triturated in cyclohexane

Procedimiento

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).

Fuente