Acetate → 3-(N',N'-Dimethyl-hydrazino)-5-phenyl-thiophene-2-carboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 3-Bromo-5-phenyl-thiophene-2-carboxylic acid methyl ester (0.500 g, 1.68 mmol) in toluene (10 ml) was added N,N-Dimethyl-hydrazine (0.121 g, 2.02 mmol), cesium carbonate (0.767 g, 2.36 mmol), BINAP (0.106 g, 0.17 mmol) and paladium(II) acetate (0.019 g, 0.08 mmol). The reaction mixture was stirred for 16 h at 110° C. The mixture was partitioned between toluene (20 mL) and water (20 mL) and the organic layer was separated. The aqueous phase was washed twice with toluene (2×10 mL) and the combined toluene layer was dried (MgSO4), concentrated and the residue was purified by preparative tlc (10% EtOAc/Hexane) to obtain 0.350 g (75%) of 3-(N′,N′-Dimethyl-hydrazino)-5-phenyl-thiophene-2-carboxylic acid methyl ester. NMR 1H (CDCl3, 400 MHz): δ 7.71 (d, 2H), 7.40 (m, 3H), 7.13 (s, 1H), 3.87 (s, 3H), 2.65 (s, 6H).

Herkunft & Nachweise