3-ETHYL-2-THIOXOIMIDAZOLIDIN-4-ONE

反应条件: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Glycine 36 (150 mg, 2.0 mmol) was dissolved in H2O (5.0 mL) and pyridine (5.0 mL) solution. The pH of the solution was adjusted to about 9.0 as shown by an indicator paper by the addition of 1M NaOH. The solution was heated to 40° C. and kept at that temperature during the reaction. Ethyl isothiocyanate 35 (0.263 mL, 3.0 mmol) was added with vigorous stirring. Small portions of 1M NaOH was added to keep the pH at about 9.0. The reaction was completed when the alkali consumption ceased (1 h). Pyridine and excess alkyl isothiocyanates were then removed by repeated extraction with equal volumes of benzene. Subsequently, an amount of conc. HCl (0.75 mL) was added and the mixture was refluxed for 2 h. The residue was extracted with ethyl acetate (2×150 mL). The organic layer was dried with brine and MgSO4, then concentrated in vacuo. Flash column chromatography on silica gel (hexane:ethyl acetate=2:1) of the residue afforded the desired product 37 in 90% yield (258 mg, pale yellow solid). 1H NMR (400 MHz, CDCl3): 6.88 (br, 1H), 4.06 (d, J=1.2 Hz, 2H), 3.89 (q, J=7.2 Hz, 2H), 1.25 (t, J=7.2 Hz, 3H). kept at that temperature during the reaction the alkali consumption (1 h) Pyridine and excess alkyl isothiocyanates were then removed extraction with equal volumes of benzene Subsequently, an amount of conc. HCl (0.75 mL) was added the mixture was refluxed for 2 h The residue was extracted with ethyl acetate (2×150 mL) The organic layer was dried with brine and MgSO4 concentrated in vacuo

反应条件: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Glycine 36 (150 mg, 2.0 mmol) was dissolved in H2O (5.0 mL) and pyridine (5.0 mL) solution. The pH of the solution was adjusted to about 9.0 as shown by an indicator paper by the addition of 1M NaOH. The solution was heated to 40° C. and kept at that temperature during the reaction. Ethyl isothiocyanate 35 (0.263 mL, 3.0 mmol) was added with vigorous stirring. Small portions of 1M NaOH was added to keep the pH at about 9.0. The reaction was completed when the alkali consumption ceased (1 h). Pyridine and excess alkyl isothiocyanates were then removed by repeated extraction with equal volumes of benzene. Subsequently, an amount of conc. HCl (0.75 mL) was added and the mixture was refluxed for 2 h. The residue was extracted with ethyl acetate (2×150 mL). The organic layer was dried with brine and MgSO4, then concentrated in vacuo. Flash column chromatography on silica gel (hexane:ethyl acetate=2:1) of the residue afforded the desired product 37 in 90% yield (258 mg, pale yellow solid). 1H NMR (400 MHz, CDCl3): 6.88 (br, 1H), 4.06 (d, J=1.2 Hz, 2H), 3.89 (q, J=7.2 Hz, 2H), 1.25 (t, J=7.2 Hz, 3H). kept at that temperature during the reaction the alkali consumption (1 h) Pyridine and excess alkyl isothiocyanates were then removed extraction with equal volumes of benzene Subsequently, an amount of conc. HCl (0.75 mL) was added the mixture was refluxed for 2 h The residue was extracted with ethyl acetate (2×150 mL) The organic layer was dried with brine and MgSO4 concentrated in vacuo