反应详情

Step R (2): 10% Palladium on carbon (0.890 g, 0.830 mmol) was added under an atmosphere of nitrogen to a chilled (ice-water bath) solution of 1-(2,6-difluoro-4-nitrophenyl)-3-methyl-1H-1,2,4-triazole (2.00 g, 8.33 mmol dissolved in methanol (200 mL). The flask was repeatedly evacuated and flushed with hydrogen gas (double balloon). The resulting mixture was allowed to warm to rt and left to stir for 18 h under the hydrogen atmosphere. The vessel was subsequently purged with nitrogen gas. The crude reaction mixture was filtered through a short plug of diatomaceous earth (Celite®). The reaction vessel and Celite® were rinsed with fresh methanol. The combined filtrates were concentrated in vacuo. The residue was dried under high vacuum to afford 3,5-difluoro-4-(3-methyl-1H-1,2,4-triazol-1-yl)aniline (1.76 g, 8.37 mmol, quantitative yield) as a blackish/gray solid. LC-MS (M+H)+ 211.1. 1H NMR (500 MHz, CHLOROFORM-d) δ ppm 8.10 (1 H, s), 6.25-6.36 (2 H, m), 4.17 (2 H, br. s.), 2.49 (3 H, s).

1. customThe flask was repeatedly evacuated
2. customflushed with hydrogen gas (double balloon)
3. waitleft
4. customThe vessel was subsequently purged with nitrogen gas
5. customThe crude reaction mixture
6. filtrationwas filtered through a short plug of diatomaceous earth (Celite®)
7. washThe reaction vessel and Celite® were rinsed with fresh methanol
8. concentrationThe combined filtrates were concentrated in vacuo
9. customThe residue was dried under high vacuum