反应详情

温度

50 °C

2.80 g (1 mol equiv.) 4-Ethyl-4,5-dihydro-pyrazole-1-carbothioic acid (2,2,2-trifluoro-ethyl)-amide was dissolved in 56 mL methanol; 7.3 mL (10 mol equiv.) iodomethane was added and the reaction mixture was heated at 50° C. for 4 hours. Volatiles were removed under reduced pressure, and the residue was taken up in DCM and extracted with 5% aqueous NaHCO3. The organic layer was washed twice with water, dried over Na2SO4, filtered and evaporated to dryness. Purification by flash chromatography on silica gel (Et2O:PA=1:1) afforded 0.57 g (19%) 4-ethyl-N-(2,2,2-trifluoro-ethyl)-4,5-dihydro-pyrazole-1-carboximidothioic acid methyl ester. 1H NMR (400 MHz, CDCl3) δ 0.99 (t, J=7.5 Hz, 3H), 1.46-1.70 (m, 2H), 2.48 (s, 3H), 3.01-3.11 (m, 1H), 3.50 (dd, J=11.5, 7.8 Hz, 1H), 3.90 (t, J=11.5 Hz, 1H), 3.99-4.11 (m, 2H), 6.85 (d, J=1.5 Hz, 1H).

1. customVolatiles were removed under reduced pressure
2. extractionextracted with 5% aqueous NaHCO3
3. washThe organic layer was washed twice with water
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. customevaporated to dryness
7. customPurification by flash chromatography on silica gel (Et2O:PA=1:1)