Reaction #1596948

Reaction equation

4-bromo-5-ethyl-2-[3-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]tetrahydropyran

hydrogen

triethylamine

→

5-ethyl-2-[3-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]tetrahydropyran

Solvents

toluene water

Conditions

Workup

1. 1
   OtherThe organic phase is separated off
2. 2
   Filtrationfiltered absorptively (SiO2, toluene)
3. 3
   ConcentrationThe filtrate is concentrated to dryness
4. 4
   Otherthe residue is recrystallised from ethanol at reduced temperature

Procedure

18.0 g (36.2 mmol) of 4-bromo-5-ethyl-2-[3-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]tetrahydropyran are hydrogenated for 30 h at a hydrogen pressure of 5 bar and at 80° C. in toluene/water in the presence of Pd/C (5% of Pd) and 12.7 ml (88.1 mmol) of triethylamine. The organic phase is separated off and filtered absorptively (SiO2, toluene). The filtrate is concentrated to dryness, and the residue is recrystallised from ethanol at reduced temperature, giving 5-ethyl-2-[3-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]tetrahydropyran as a colourless solid.

Source