Reaction #2329007

Reaction equation

NaHCO3

EtOAc

5-(6-methoxy-1,3-benzoxazol-2-yl)pyridin-2-amine

boron tribromide

→

2-(6-aminopyridin-3-yl)-1,3-benzoxazol-6-ol

Yield 116.9%

Solvents

CH2Cl2

CH2Cl2

water

CH2Cl2

Conditions

Workup

1. 1
   workup.ADDITIONAfter full addition the reaction mixture
2. 2
   Otherto reach room temperature
3. 3
   workup.STIRRINGstirred at room temperature overnight
4. 4
   TemperatureThe reaction mixture was cooled (ice bath)
5. 5
   Otherto reach room temperature
6. 6
   workup.STIRRINGstirred vigorously for 10 mins
7. 7
   OtherThe organic layer was separated
8. 8
   Extractionthe aqueous layer extracted with CH2Cl2 (3×100 mL)
9. 9
   Dryingthe combined organic layers were dried (Na2SO4)
10. 10
    Filtrationfiltered
11. 11
    Otherevaporated

Procedure

To a stirred and cooled (ice bath) solution of 5-(6-methoxy-1,3-benzoxazol-2-yl)pyridin-2-amine (2.07 mmol) in CH2Cl2 (50 mL) was slowly added boron tribromide 1M in CH2Cl2 (4.15 mL) from a pressure equalized dropping funnel. After full addition the reaction mixture was stirred 5 mins in the ice bath, before it was allowed to reach room temperature and then stirred at room temperature overnight. The reaction mixture was cooled (ice bath) and diluted with CH2Cl2 (100 mL), followed by EtOAc (100 mL), water (100 mL) and sat aq NaHCO3 (100 mL) and the resulting mixture allowed to reach room temperature and stirred vigorously for 10 mins. The organic layer was separated and the aqueous layer extracted with CH2Cl2 (3×100 mL), the combined organic layers were dried (Na2SO4), filtered and evaporated to give 0.55 g of 2-(6-aminopyridin-3-yl)-1,3-benzoxazol-6-ol, as a pale yellow foamy solid. MS m/z 228 (M+H).

Source