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

HRID 1807972

Reaction equation

[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[CH:8][C:9]=1Br)=[O:4].[CH3:17][N:18]([CH3:20])[NH2:19].C(=O)([O-])[O-].[Cs+].[Cs+].C1C=CC(P(C2C(C3C(P(C4C=CC=CC=4)C4C=CC=CC=4)=CC=C4C=3C=CC=C4)=C3C(C=CC=C3)=CC=2)C2C=CC=CC=2)=CC=1.C([O-])(=O)C>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[CH:8][C:9]=1[NH:19][N:18]([CH3:20])[CH3:17])=[O:4]

Participants

Conditions

Temperature: 110 °C

Procedure

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).

Workup

customThe mixture was partitioned between toluene (20 mL) and water (20 mL)
customthe organic layer was separated
washThe aqueous phase was washed twice with toluene (2×10 mL)
dry with materialthe combined toluene layer was dried (MgSO4)
concentrationconcentrated
customthe residue was purified by preparative tlc (10% EtOAc/Hexane)

Sources & evidence

ORD record: ord-9fafd073a0664d5eab0a571f1ad716bc
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08357718B2

Linked notes

Loading…