反应详情

温度

40 °C

Following the procedure of Japan Kokai Tokkyo Koho JP 60 11,487 CA 103:22580m (1985), a solution of bromine (4.29 g, 26.87 mmoles) in 40 ml of chloroform was added dropwise to a stirred solution of methyl 4-acetyl-2-thiophenecarboxylate, prepared according to Example 15 (4.95 g, 26.87 mmoles) in 150 ml of chloroform containing four drops of 50% (v/v) 48% hydrobromic acid/glacial acetic acid. After 10 minutes at 40° C. the solution was cooled to room temperature, concentrated in vacuo and the residue triturated with methanol (25 ml). Filtration furnished an off-white solid (4.96 g, 63%), m.p. 112-4° C. EIMS (m/z): 264/262 (M+, 11%), 233/231 (M+ --CH3O, 11%) , 171/169 (M+ --CH2Br, base); 1HNMR (CDCl3) delta, 8.31 (1H, d, J=1.5 Hz), 8.17 (1H, d, J=1.5 Hz), 4.29 (2H, s), 3.90 (3H, s).

1. customprepared
2. concentrationconcentrated in vacuo
3. customthe residue triturated with methanol (25 ml)
4. filtrationFiltration