反应详情

To a stirred solution of tetrazole (1.0 g; 14 mmol) in DMF (150 mL) was added 40% aqueous tetrabutylammonium hydroxide (7.8 g; 12 mmol). The solvent was removed under reduced pressure. To ensure removal of all the water from the tetrabutylammonium hydroxide solution, the residue was redissolved in DMF and the solution was evaporated under reduced pressure. This procedure was repeated a total of three times. The residue was then dissolved in DMF (60 mL) and 3-fluoro-2-cyanopyridine (1.5 g; 12 mmol) was added. The reaction was stirred at ambient temperature under inert atmosphere for four days, at which time hplc analysis indicated about 65% conversion of the 3-fluoro-2-cyanopyridine to new products. The solvent was removed under reduced pressure and the residue was partitioned between EtOAc and water. The EtOAc layer was separated, dried over anhydrous MgSO4, and filtered. The solvent was removed under reduced pressure and the residue was purified by flash chromatography using a gradient elution of 1:4 to 100:0 EtOAc:hexanes to give 3-(tetrazol-1-yl)cyanopyridine as a white crystalline solid (TLC Rf=0.5, 1:1 EtOAc-hexanes; hplc retention time =2.04 min, method X; 1H NMR (CDCl3) δ9.42 (s, 1H), 8.94 (dd, J=1.3, 4.6 Hz, 1H), 8.31 (dd, J=1.3, 8.4 Hz, 1H), 7.87 (dd, J=4.6, 8.4 Hz, 1H).

1. customThe solvent was removed under reduced pressure
2. customremoval of all the water from the tetrabutylammonium hydroxide solution
3. dissolutionthe residue was redissolved in DMF
4. customthe solution was evaporated under reduced pressure
5. dissolutionThe residue was then dissolved in DMF (60 mL)
6. customThe solvent was removed under reduced pressure
7. customthe residue was partitioned between EtOAc and water
8. customThe EtOAc layer was separated
9. dry with materialdried over anhydrous MgSO4
10. filtrationfiltered
11. customThe solvent was removed under reduced pressure
12. customthe residue was purified by flash chromatography
13. washa gradient elution of 1:4 to 100:0 EtOAc