Lithium hydroxide, monohydrate → 3-[N-(2,4-Dichloro-benzoyl)-N',N'-dimethyl-hydrazino]-5-phenyl-thiophene-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

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-carboxy-lic 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).

Provenance & Evidence