Methyl iodide → HCID 67360167, compound

Participants

Reaction Conditions

Reaction Steps

0.70 g (1 mol equiv.) 5-Thiophen-3-yl-4,5-dihydro-pyrazole-1-carbothioic acid ethylamide was dissolved in 14 mL methanol, 1.82 mL (10 mol equiv.) iodomethane was added and the reaction mixture was heated at 50° C. for 1 hour. Volatiles were removed in vacuo, the residue was taken up in dichloromethane 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 (EtOAc:MeOH=9:1) afforded 0.48 g (64%) N-ethyl-5-thiophen-3-yl-4,5-dihydro-pyrazole-1-carboximidothioic acid methyl ester. 1H NMR (400 MHz, CDCl3) δ 1.03 (t, J=7.3, 3H), 2.44 (s, 3H), 2.84 (ddd, J=18.1, 10.4, 1.5 Hz, 1H), 3.23-3.51 (m, 3H), 5.57 (t, J=10.4 Hz, 1H), 6.87 (br.s., 1H), 7.00 (d, J=4.8, 1H), 7.13 (d, J=3.0, 1H), 7.24 (dd, J=4.8, 3.0 Hz, 1H).

Provenance & Evidence