[CH3:1][C:2]1[C:7]2[N:8]=[CH:9][S:10][C:6]=2[CH:5]=[CH:4][CH:3]=1.C1C(=O)N([Br:18])C(=O)C1.CC(N=NC(C#N)(C)C)(C#N)C>C(Cl)(Cl)(Cl)Cl>[Br:18][CH2:1][C:2]1[C:7]2[N:8]=[CH:9][S:10][C:6]=2[CH:5]=[CH:4][CH:3]=1A solution of 4-Methyl benzothiazole (16.0 g, 107 mmol) in 535 mL of CCl4 was treated with NBS (19.0 g, 107 mmol) and AIBN (2.28 g, 13.9 mmol) at 20° C. and stirred at 70° C. for 2.5 h. The resulting mixture was filtered through Celite washing with Et2O (150 mL) and concentrated in vacuo. The residue was submitted to a silica gel column chromatography with toluene:Et2O=50:3 to 50:5 as eluate to afford 4-bromomethyl benzothiazole as a yellowish solid. (20.4 g, 89.9 mmol, 84%) Rf=0.61 (toluene-Et2O 10:1); 1H NMR (400 MHz, CDCl3) δ 9.07 (1H, s), 7.90 (1H, d, J=7.5 Hz), 7.55 (1H, d, J=7.5 Hz), 7.41 (1H, t, J=7.5 Hz), 5.08 (2H, s); 13C NMR (99.5 MHz, CDCl3) δ 154.1, 151.4, 134.3, 132.6, 127.0, 125.6, 122.3, 29.5.
Wird geladen…
