반응 #9202

반응 방정식

Et2O

2-amino-7-oxo-4,5,6,7-tetrahydro-benzothiazole

2-Amino-7-oxo-4, 5, 6, 7-tetrahydro-benzothiazole

triethylamine

ethyl isocyanate

→

4

수율 85.0%

1-(7-Oxo-4,5,6,7-tetrahydro-2-benzothiazolyl)-3-ethyl-urea

수율 85.0%

용매

DMF

반응 조건

후처리

1. 1
   workup.DISTILLATIONThe DMF solvent was distilled off under reduced pressure
2. 2
   기타A sticky brown residue was obtained
3. 3
   여과was filtered off
4. 4
   세척washed with more Et2O (50 mL)
5. 5
   기타The light brown colored solid was dried under vacuum

실험 절차

A solution of 2-amino-7-oxo-4,5,6,7-tetrahydro-benzothiazole 3 (11.56 g, 68.7 mmol) in anhydrous DMF (200 mL) was treated with triethylamine (19.2 mL, 137 mmol, 2.0 eq) and ethyl isocyanate (10.9 nL, 137 mmol, 2.0 eq). The reaction mixture was heated at about 90° C. with stirring for about 3 hours. The DMF solvent was distilled off under reduced pressure. A sticky brown residue was obtained. Treatment with Et2O (100 mL) gave a precipitate, which was filtered off and washed with more Et2O (50 mL). The light brown colored solid was dried under vacuum to give 13.97 g (85%) of 4. The material was used in the following synthesis without further purification. 1H NMR (DMSO) δ 10.95 (br s, 1H, NH), 6.66 (br s, 1H, NH), 3.16 (p, 2H, J=7.2 Hz, CH2), 2.79 (t, 2H, J=6.1 Hz, CH2), 2.45 (t, 2H, J=6.5 Hz, CH2), 2.05 (p, 2H, J=6.4 Hz, CH2), 1.07 (t, 3H, J=7.2 Hz, CH3); LC/MS 240 (MH+); RP-HPLC RT 2.27 minutes.

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