反应详情

0.75 g (1 mol equiv.) N-Ethyl-4,4-dimethyl-4,5-dihydro-pyrazole-1-carboximidothioic acid methyl ester and 0.94 g (1.05 mol equiv.) 3-chloro-4-methoxy-benzenesulfonamide were added to 10 mL acetonitrile. The reaction mixture was refluxed overnight and volatiles were removed in vacuo. 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) afforded 1.43 g (97%) 3-chloro-N-[(4,4-dimethyl-4,5-dihydro-pyrazol-1-yl)-ethylamino-methylene]-4-methoxy-benzenesulfonamide. 1H NMR (400 MHz, CDCl3) δ 1.17 (t, J=7.3 Hz, 3H), 1.22 (s, 6H), 3.43-3.52 (m, 2H), 3.77 (br.s., 2H), 3.95 (s, 3H), 6.75 (s, 1H), 6.96 (d, J=8.6 Hz, 1H), 6.70-6.90 (br.s., 1H) 7.82 (dd, J=8.6, 2.3 Hz, 1H), 7.95 (d, J=2.3 Hz, 1H).

1. temperatureThe reaction mixture was refluxed overnight
2. customvolatiles were removed in vacuo
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)