Reaction #9074

Reaction equation

Na2CO3

4-bromobenzaldehyde

thiophene-2-boronic acid

→

title compound

Yield 78.0%

4-thiophen-2-yl-benzaldehyde

Yield 78.0%

Solvents

DME THF

Conditions

Workup

1. 1
   OtherThe reaction mixture was flushed with argon
2. 2
   Temperaturemaintained under argon
3. 3
   TemperatureThe mixture was then cooled
4. 4
   workup.ADDITIONdiluted with EtOAc (35 mL) and water (30 mL)
5. 5
   WashThe aqueous layer was washed with EtOAc (2×10 mL)
6. 6
   Dryingthe combined organic extracts dried (Na2SO4)
7. 7
   Filtrationfiltered
8. 8
   Concentrationconcentrated
9. 9
   OtherPurification of the resultant oil by column chromatography on silica gel (Hexanes/EtOAc, 4:1)

Procedure

To a stirred degassed solution of 4-bromobenzaldehyde (371 mg, 2.00 mmol) and thiophene-2-boronic acid (287 mg, 2.24 mmol) in DME/THF (5 mL, 4:1) were added a 2 M Na2CO3 solution (3.0 mL) and Pd(PPh3)4 (110 mg, 0.095 mmol). The reaction mixture was flushed with argon and maintained under argon while being heated at 85° C. over 2 days. The mixture was then cooled and diluted with EtOAc (35 mL) and water (30 mL). The aqueous layer was washed with EtOAc (2×10 mL) and the combined organic extracts dried (Na2SO4), filtered and concentrated. Purification of the resultant oil by column chromatography on silica gel (Hexanes/EtOAc, 4:1) afforded the title compound (293 mg, 78%) as a yellow solid. 1H NMR (CDCl3) δ 7.14 (dd, 1H, J=5.1, 3.6 Hz), 7.40 (dd, 1H, J=5.1, 0.9 Hz), 7.46 (dd, 1H, J=3.6, 0.9 Hz), 7.76 (d, 2H, J=8.4 Hz), 7.88 (d, 2H, J=8.4 Hz), 10.00 (s, 1H).

Source