反应详情

To a suspension of 4-(2-bromo-5-fluorobenzyl)-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one (16, 914 mg, 2.77 mmol) in ethanol (15 mL) was added NaOH (111 mg, 2.77 mmol) followed by MeI (787 mg, 5.54 mmol). The mixture was stirred at RT for 10 min to produce a clear yellow solution. The reaction was diluted with water (100 mL), and extracted with EtOAc (30 mL×2). The extracts were washed with brine, dried over MgSO4 and concentrated to give the crude product. This was purified by silica gel column, and eluted with 20-25% ethyl acetate in petroleum ether to give 4-(2-bromo-5-fluorobenzyl)-6-methyl-3-(methylthio)-1,2,4-triazin-5(4H)-one (17). 1H NMR (400 MHz, DMSO, ppm): δ 7.73 (m, 1H), 7.16 (br, 1H), 7.05 (d, 1H), 5.09 (s, 2H), 2.56 (s, 3H), 2.32 (s, 3H). MS: m/z, 344 (100%, M+1), 346 (100%).

1. customto produce a clear yellow solution
2. extractionextracted with EtOAc (30 mL×2)
3. washThe extracts were washed with brine
4. dry with materialdried over MgSO4
5. concentrationconcentrated
6. customto give the crude product
7. customThis was purified by silica gel column
8. washeluted with 20-25% ethyl acetate in petroleum ether