反应详情

To a stirred suspension of 6-aminonicotinic acid (100 g, 0.72 mol; Aldrich Chemical Company, Inc., Milwaukee, Wis.) in N,N-dimethylformamide (700 mL) with brisk mechanical stirring was added potassium carbonate (150 g, 1.08 mol) and the reaction was stirred for 10 min before the portionwise addition of benzyl bromide (95 mL, 0.80 mol). The reaction was stirred at room temperature overnight, then the solids were filtered off and washed thoroughly with ethyl acetate, and the solvent was removed under vacuum. The filter cake was dissolved in water and extracted with ethyl acetate. The residue after evaporation of N,N-dimethylformamide was combined with the ethyl acetate extracts (total volume 2 L of ethyl acetate) and the combined organic extracts washed with brine (5×500 mL), dried (MgSO4) and the solvent removed under reduced pressure. The crude product was refluxed with 1:1 diethyl ether:hexane for 30 min then the solids filtered off (warm), washed with diethyl ether:hexane (1:1), and dried. This solid was precipitated from hot toluene (hot filtration required to remove dibenzylated material) and dried to afford (I-28a) (107.2 g, 65%) as an off-white solid; 1H NMR (DMSO-d6): δ 8.50 (1H), 7.82 (1H), 7.34-7.29 (5H), 6.84 (2H), 6.43 (1H), 5.23 (2H); m/z 229.4 (M+H)+.

1. stirringThe reaction was stirred at room temperature overnight
2. filtrationthe solids were filtered off
3. washwashed thoroughly with ethyl acetate
4. customthe solvent was removed under vacuum
5. dissolutionThe filter cake was dissolved in water
6. extractionextracted with ethyl acetate
7. customThe residue after evaporation of N,N-dimethylformamide
8. washthe combined organic extracts washed with brine (5×500 mL)
9. dry with materialdried (MgSO4)
10. customthe solvent removed under reduced pressure
11. temperatureThe crude product was refluxed with 1:1 diethyl ether
12. filtrationthe solids filtered off
13. temperature(warm)
14. washwashed with diethyl ether:hexane (1:1)
15. customdried
16. customThis solid was precipitated from hot toluene (hot filtration required to remove dibenzylated material)
17. customdried
18. customto afford (I-28a) (107.2 g, 65%) as an off-white solid