反应详情

温度

45 °C

A solution of 1-(7-oxo-4,5,6,7-tetrahydro-2-benzothiazolyl)-3-ethyl-urea 4 (5.00 g, 20.9 mmol), 48% HBr (aq) (1.20 mL, 2.09 mmol, 0.1 eq) and AcOH (451 mL) was treated dropwise with a solution of Br2 (2.21 mL, 42.8 mmol, 2.05 eq) in AcOH (5 mL) with stirring. The reaction mixture was heated at about 45° C. with stirring for about 16 hours with a condensor on top of the reaction flask. An orange colored suspension was obtained. The solid was filtered off and washed with Et2O (20 mL), toluene (50 mL) and Et2O (3×30 mL). After drying under vacuum, 7.78 g (94%) of compound 5 was obtained. 1H NMR (DMSO) δ 11.35 (br s, 1H, NH), 6.78 (br s, 1H, NH), 3.18 (m, 2H, CH2), 3.12 (t, 2H, J=5.6 Hz, CH2), 2.91 (t, 2H, J=5.6 Hz, CH2), 1.08 (t, 3H, J=7.2 Hz, CH3); LC/MS 396 (MH+); RP-HPLC RT 3.04 minutes.

1. stirringwith stirring for about 16 hours with a condensor on top of the reaction flask
2. customAn orange colored suspension was obtained
3. filtrationThe solid was filtered off
4. washwashed with Et2O (20 mL), toluene (50 mL) and Et2O (3×30 mL)
5. customAfter drying under vacuum