反应详情

温度

60 °C

3-[N-(2,4-Dichloro-benzoyl)-N′,N′-dimethyl-hydrazino]-5-phenyl-thiophene-2-carboxylic acid methyl ester (0.050 g, 0.11 mmol) was taken in a mixture of THF:MeOH:H2O (3:2:1, 10 mL) and then added 1N aqueous solution of LiOH.H2O (0.67 mL, 0.67 mmol). The reaction mixture was stirred at 60° C. for 2 h. Solvents were removed and the residue was partitioned between water and ethyl acetate. The aqueous layer was acidified using 10% KHSO4 solution. The organic layer was separated, dried (Na2SO4) and concentrated. The residue was purified by preparative TLC using dicholomethane:methanol (9:1) to obtain 3-[N-(2,4-Dichloro-benzoyl)-N′,N′-dimethyl-hydrazino]-5-phenyl-thiophene-2-carboxylic acid (Compound 72) (0.008 g, 17%). 1H NMR (DMSO, 400 MHz): δ 7.81 (d, 2H), 7.69 (d, 2H), 7.54-7.40 (m, 5H), 2.42 (s, 6H).

1. customSolvents were removed
2. customthe residue was partitioned between water and ethyl acetate
3. customThe organic layer was separated
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated
6. customThe residue was purified by preparative TLC