Triethylamine → HCID 58366245, compound

Participants

Reaction Steps

2-Thiophenecarboxylic acid hydrazide (200 mg, 1.4 mmol) and Et3N (392 μL, 2.8 mmol) were dissolved in CH2Cl2 (7 mL) and treated with methyl oxalyl chloride (130 μL, 1.4 mmol) dropwise at 0° C. The reaction mixture was warmed slowly to room temperature and stirred for 16 h before the solvent was removed in vacuo. The residue was dissolved in toluene (13 mL) and treated with recrystallized Lawesson's reagent (1.14 g, 2.1 mmol), and warmed at 110° C. for 6 h. Upon completion, the reaction mixture was diluted with EtOAc and washed with water, saturated aqueous NaHCO3 and saturated aqueous NaCl. The organic layer was dried over Na2SO4 and the solvent was removed under reduced pressure. Flash chromatography (SiO2, 3×18 cm, 25% EtOAc-hexanes) afforded the title compound (106 mg, 33%) as a yellow solid: 1H NMR (CDCl3, 500 MHz) δ 7.66 (dd, 1H, J=0.9, 3.7 Hz), 7.58 (dd, 1H, J=0.9, 5.1 Hz), 7.16 (dd, 1H, J=3.9, 4.8 Hz), 4.05 (s, 3H); 13C NMR (CDCl3, 150 MHz) δ 166.5, 159.2, 158.4, 131.5, 131.2, 131.17, 128.5, 53.9; HRMS-ESI-TOF m/z 226.9943 ([M+H]+, C8H6N2O2S2 requires 226.9943).

Provenance & Evidence