Dimethylformamide → 2-Chloro-6-fluoro-3-methylbenzaldehyde

Temperatur

-30 °C

A solution of 1.3M s-butyl lithium in cyclohexane (75 mL, 98 mmol) is added to a dry-ice/acetone cooled solution of TMEDA (9.67 g, 83 mmol) in THF (90 mL), maintaining the internal reaction temperature <-70° C. The reaction mixture is cooled and maintained at ≤-80° C. with an ether/liquid nitrogen bath while a solution of 2-chloro-4-fluorotoluene (10 g, 69 mmol) in THF (10 mL) is added dropwise. The resulting reaction mixture is stirred with dry-ice/acetone cooling for 1h, then is cannulated into an ether/liquid nitrogen cooled and mechanically stirred solution of DMF (25.1 g, 345 mmol) in THF (50 mL). The resulting mixture is warmed to -30° C. and partitioned between dilute aqueous HCl and ether. The organic solution is washed with aqueous NaHCO3, dried (MgSO4), and concentrated and triturated with hexanes to afford 2-fluoro-5-methyl-6-chlorobenzaldehyde as a crystalline solid.

1. temperaturemaintaining the internal reaction temperature <-70° C
2. temperatureThe reaction mixture is cooled
3. additionis added dropwise
4. customThe resulting reaction mixture
5. temperaturecooled
6. custompartitioned between dilute aqueous HCl and ether
7. washThe organic solution is washed with aqueous NaHCO3
8. dry with materialdried (MgSO4)
9. concentrationconcentrated
10. customtriturated with hexanes

ORD-Eintrag

ord-836b52912f9942059d71827ee5d90a0e

Quelldatensatz

uspto-grants-1996_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05482974