反应详情

Charged about 500 mg N-ethyl-N′-(6-nitro-1,3-benzothiazol-2-yl)urea into about 75 ml ethanol. Added about 20 mg platinum oxide then evacuated and released to hydrogen three times. The system was then put under hydrogen pressure (about 20–40 psi) for about 5–20 hours. The reaction was stopped and the entire mass was filtered through diatomaceous earth and washed with methanol. The solvent was removed in vacuo and the crude N-(6-amino-1,3-benzothiazol-2-yl)-N′-ethylurea was used for the next step without further purification. Charged about 0.44 g N-(6-amino-1,3-benzothiazol-2-yl)-N′-ethylurea into about 15 ml acetic acid then added about 0.23 ml 2,5-dimethoxytetrahydrofuran. Refluxed for about 1 hour then cooled to room temperature. The solvent was removed in vacuo and the product was purified by preparative HPLC. 1H NMR 1.1 (t, 3H), 3.2 (m, 2H), 6.26 (m, 2H), 6.71 (m, 1H), 7.35 (m, 2H), 7.55 (m, 1H), 7.7 (m, 1H), 8.1 (m, 1H), 10.69 (br s, 1H); LC/MS 3.1 min, 285 (M−1).

1. customthen evacuated
2. customfor about 5–20 hours
3. filtrationthe entire mass was filtered through diatomaceous earth
4. washwashed with methanol
5. customThe solvent was removed in vacuo
6. customthe crude N-(6-amino-1,3-benzothiazol-2-yl)-N′-ethylurea was used for the next step without further purification
7. additionCharged about 0.44 g N-(6-amino-1,3-benzothiazol-2-yl)-N′-ethylurea into about 15 ml acetic acid
8. additionthen added about 0.23 ml 2,5-dimethoxytetrahydrofuran
9. temperatureRefluxed for about 1 hour
10. customThe solvent was removed in vacuo
11. customthe product was purified by preparative HPLC
12. customLC/MS 3.1 min, 285 (M−1)