反应详情

温度

20 °C

A suspension of 1-(6,6-dibromo-7-oxo-4,5,6,7-tetrahydro-2-benzothiazolyl)-3-ethyl-urea 5 (7.78 g, 19.6 mmol) in THF (50 mL) was treated with DBU (8.79 mL, 58.8 mmol, 3.0 eq) dropwise at about 20° C. A dark green suspension was obtained while heat was generated upon addition of DBU. It was stirred at about 20° C. for about 18 hours. The reaction mixture was concentrated and the residue was treated with saturated NH4Cl (aq) solution to neutral. A light brown colored precipitate was obtained. It was filtered off and washed with H2O (2×50 mL), small amount of MeOH and CH2Cl2, and finally dried under vacuum to give 4.83 g (78%) of the desired compound 6. 1H NMR (DMSO) δ 10.68 (br s, 1H, NH), 7.43 (d, 1H, J=8.5 Hz, ArH), 7.08 (d, 1H, J=8.5 Hz, ArH), 6.70 (br s, 1H, NH), 3.18 (m, 2H, CH2), 1.09 (t, 3H, J=7.2 Hz, CH3). LC/MS 316 (MH+); RP-HPLC RT 2.80 minutes.

1. customA dark green suspension was obtained
2. temperaturewhile heat
3. concentrationThe reaction mixture was concentrated
4. additionthe residue was treated with saturated NH4Cl (aq) solution to neutral
5. customA light brown colored precipitate was obtained
6. filtrationIt was filtered off
7. washwashed with H2O (2×50 mL), small amount of MeOH and CH2Cl2
8. customfinally dried under vacuum