(Pyridin-4-yl)boronic acid → 2-Amino-3-nitro-5-pyridin-4-yl-benzoic acid methyl ester

HRID 1845047Notes

Reaction equation

[CH3:1][O:2][C:3](=[O:15])[C:4]1[CH:9]=[C:8](Br)[CH:7]=[C:6]([N+:11]([O-:13])=[O:12])[C:5]=1[NH2:14].[N:16]1[CH:21]=[CH:20][C:19](B(O)O)=[CH:18][CH:17]=1>COCCOC.C([O-])([O-])=O.[Na+].[Na+]>[CH3:1][O:2][C:3](=[O:15])[C:4]1[CH:9]=[C:8]([C:19]2[CH:20]=[CH:21][N:16]=[CH:17][CH:18]=2)[CH:7]=[C:6]([N+:11]([O-:13])=[O:12])[C:5]=1[NH2:14]

Participants

Conditions

Temperature: 90 °C

Procedure

A solution of 1.0 g (3.6 mmol) of 2-amino-5-bromo-3-nitro-benzoic acid methyl ester, 0.9 g (7.2 mmol) of pyridine-4-boronic acid, 0.42 g (0.36 mmol) of (tetrakistriphenyl phosphine) palladium (0) in 50 mL of DME and 8.4 mL of 2 N Na2CO3 was degassed with nitrogen for 20 min and then heated at 90° C. for 12 h. The reaction mixture was cooled to r.t., extracted with ethyl acetate (100 mL), washed with water, brine, dried over magnesium sulfate, and filtered. The filtrate was concentrated under reduced pressure. The residue was purified by column chromatography using 8:2 hexane and ethyl acetate to afford 0.5 g (50%) of the 2-Amino-3-nitro-5-pyridin-4-yl-benzoic acid methyl ester as a solid. LCMS: 273 (M+1)+.

Workup

temperatureThe reaction mixture was cooled to r.t.
extractionextracted with ethyl acetate (100 mL)
washwashed with water, brine
dry with materialdried over magnesium sulfate
filtrationfiltered
concentrationThe filtrate was concentrated under reduced pressure
customThe residue was purified by column chromatography

Sources & evidence

ORD record: ord-f02b4dc0e2c14aeda599108dd174af27
Source dataset: uspto-grants-2015_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08946259B2

Reaction notes

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