Reaction #8237

Reaction equation

Naphthylboronic acid

Na2CO3

2-bromo-6-formylpyridine

→

2-formyl-6-naphthylpyridine

Solvents

toluene

Conditions

Workup

1. 1
   Otherof degassed 4:1 H2O/MeOH
2. 2
   TemperatureOn cooling to RT
3. 3
   Otherthe organic phase was separated
4. 4
   Washwashed with 3×25 mL of Et2O
5. 5
   WashThe combined organic extracts were washed with 3×25 mL of H2O and 1×20 mL of brine
6. 6
   Dryingdried over Na2SO4
7. 7
   OtherAfter removing the volatiles in vacuo
8. 8
   Otherthe resultant brown oil was chromatographed on silica with 0–50% hexanes/CH2Cl2
9. 9
   Otherthe volatiles were removed
10. 10
    Otherto provide 2-formyl-6-naphthlypyridine as a white solid

Procedure

Naphthylboronic acid (2.06 g, 12 mmol) and Na2CO3 (2.65 g, 25 mmol) were dissolved in 60 mL of degassed 4:1 H2O/MeOH. This solution was added via cannula to a solution of 1.86 g (10 mmol) of 2-bromo-6-formylpyridine and I 16 mg (0.10 mmol) of Pd(PPh3)4 in 50 mL of degassed toluene. The biphasic solution was vigorously stirred and heated to 70° C. under N2 for 4 h. On cooling to RT, the organic phase was separated and washed with 3×25 mL of Et2O. The combined organic extracts were washed with 3×25 mL of H2O and 1×20 mL of brine and dried over Na2SO4. After removing the volatiles in vacuo, the resultant brown oil was chromatographed on silica with 0–50% hexanes/CH2Cl2. The early fractions contained naphthalene and binaphthyl and were discarded. The remaining fractions were combined and the volatiles were removed to provide 2-formyl-6-naphthlypyridine as a white solid.

Source