Reaction #1135848

Reaction equation

3-bromo-5-nitropyridin-4-amine

pyridin-3-ylboronic acid

Na2CO3

→

5-nitro-3,3′-bipyridin-4-amine

Yield 88.8%

Solvents

1,4-dioxane

Conditions

Workup

1. 1
   Temperaturethe solution was refluxed for 15 h until TLC
2. 2
   Concentrationconcentrated under reduced pressure
3. 3
   ConcentrationThe reaction mixture was concentrated
4. 4
   ExtractionThe organic extract
5. 5
   Washwas washed with water
6. 6
   Otherdried
7. 7
   Concentrationconcentrated under vacuum
8. 8
   OtherThe crude product was purified on a silica gel column (100% EtOAc→2:98 MeOH:DCM)

Procedure

A solution of 3-bromo-5-nitropyridin-4-amine (XIII) (6 g, 26 mmol), pyridin-3-ylboronic acid (3.54 g, 29 mmol), 1 N Na2CO3 solution (78 ml) and 1,4-dioxane (150 mL) was degassed with argon thrice. Pd(PPh3)2Cl2 (927 mg, 5 mmol %) was added to the reaction and the solution was refluxed for 15 h until TLC showed the reaction was complete. The reaction was passed through a pad of Celite and then concentrated under reduced pressure. The reaction mixture was concentrated and the residue was taken up in ethyl acetate. The organic extract was washed with water, dried and concentrated under vacuum. The crude product was purified on a silica gel column (100% EtOAc→2:98 MeOH:DCM) to give 5-nitro-3,3′-bipyridin-4-amine (XIV) as a yellow solid (5 g, 23.1 mmol, 87% yield). 1H NMR (CDCl3, 400 MHz,) δ ppm 9.31 (s, 1H), 8.80-8.79 (m, 1H), 8.70 (s, 1H), 8.23 (s, 1H), 7.80-7.73 (m, 1H), 7.52-7.48 (m, 1H). ESIMS found C10H8N4O2 m/z 216.95 (M+H).

Source