反应详情

0.57 g (1 mol equiv.) 4-Ethyl-N-(2,2,2-trifluoro-ethyl)-4,5-dihydro-pyrazole-1-carboximidothioic acid methyl ester and 3.0 g (6.8 mol equiv.) 3-chloro-benzenesulfonamide were added to 20 mL acetonitrile. The reaction mixture was refluxed for 72 hours, and volatiles were removed under reduced pressure. The residue was taken up in ethyl acetate and extracted with 2N NaOH. The organic layer was dried over Na2SO4, filtered and evaporated to dryness. Purification by flash chromatography on silica gel (Et2O:PA=1:1) afforded 0.36 g (38%) 3-chloro-N-[(4-ethyl-4,5-dihydro-pyrazol-1-yl)-(2,2,2-trifluoro-ethylamino)-methylene]-benzenesulfonamide. 1H NMR (400 MHz, CDCl3) δ 1.00 (t, J=7.5 Hz, 3H), 1.51-1.74 (m, 2H), 3.16-3.27 (m, 1H), 3.87 (dd, J=11.2, 7.5 Hz, 1H), 4.03-4.14 (m, 2H), 4.28 (t, J=11.2 Hz, 1H), 7.03 (d, J=1.5 Hz, 1H), 7.41 (t, J=7.8 Hz, 1H), 7.46-7.50 (m, 1H), 7.79-7.84 (m, 1H), 7.91-7.94 (m, 1H).

1. temperatureThe reaction mixture was refluxed for 72 hours
2. customvolatiles were removed under reduced pressure
3. extractionextracted with 2N NaOH
4. dry with materialThe organic layer was dried over Na2SO4
5. filtrationfiltered
6. customevaporated to dryness
7. customPurification by flash chromatography on silica gel (Et2O:PA=1:1)