Potassium Phosphate, Tribasic → Ethyl 2-(3-bromo-5-phenylthiophen-2-yl)-2-(tert-butoxy)acetate

HRID 590987Notes

Reaction equation

[C:1]([O:5][CH:6]([C:12]1[S:13][C:14](Br)=[CH:15][C:16]=1[Br:17])[C:7]([O:9][CH2:10][CH3:11])=[O:8])([CH3:4])([CH3:3])[CH3:2].P([O-])([O-])([O-])=O.[K+].[K+].[K+].[C:27]1(B(O)O)[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1>O1CCCC1.C([O-])(=O)C.[Pd+2].C([O-])(=O)C.CC1(C)C2C(=C(P(C3C=CC=CC=3)C3C=CC=CC=3)C=CC=2)OC2C(P(C3C=CC=CC=3)C3C=CC=CC=3)=CC=CC1=2>[Br:17][C:16]1[CH:15]=[C:14]([C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=2)[S:13][C:12]=1[CH:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])[C:7]([O:9][CH2:10][CH3:11])=[O:8]

Participants

Conditions

Temperature: 60 °C

Procedure

To a solution of ethyl 2-(tert-butoxy)-2-(3,5-dibromothiophen-2-yl)acetate (10c) (70 mg, 0.17 mmol) in tetrahydrofuran (1 mL) were added tripotassium phosphate (111 mg, 0.52 mmol), phenylboronic acid (23 mg, 0.19 mmol) and a solution of palladium acetate (1.2 mg, 5.2 μmol) and xantphos (3.0 mg, 5.2 μmol) in tetrahydrofuran (1 mL) previously stirred for 5 minutes. The reaction mixture was heated at 60° C. for 3 hours. The mixture was then filtered and the precipitate was rinsed with dichloromethane (5 mL). The filtrate was concentrated in vacuo. The residue was purified by flash chromatography (cyclohexane/ethyl acetate 80/20) to provide the desired product (10d) (45 mg, 0.11 mmol, 65%).

Workup

filtrationThe mixture was then filtered
washthe precipitate was rinsed with dichloromethane (5 mL)
concentrationThe filtrate was concentrated in vacuo
customThe residue was purified by flash chromatography (cyclohexane/ethyl acetate 80/20)

Sources & evidence

ORD record: ord-32173e6a3ae54120bc11d7ca52c6b78c
Source dataset: uspto-grants-2016_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09238026B2

Reaction notes

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