Stannane, tributyl(1-ethoxyethenyl)- → Methyl 4-amino-6-(1-ethoxyvinyl)-3-methoxypicolinate

HRID 407246Notes

Reaction equation

[NH2:1][C:2]1[CH:7]=[C:6](Br)[N:5]=[C:4]([C:9]([O:11][CH3:12])=[O:10])[C:3]=1[O:13][CH3:14].C([Sn](CCCC)(CCCC)[C:20]([O:22][CH2:23][CH3:24])=[CH2:21])CCC.[Sn]>ClCCCl.[Pd].Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[NH2:1][C:2]1[CH:7]=[C:6]([C:20]([O:22][CH2:23][CH3:24])=[CH2:21])[N:5]=[C:4]([C:9]([O:11][CH3:12])=[O:10])[C:3]=1[O:13][CH3:14]

Participants

Conditions

Temperature: 120 °C

Procedure

Methyl 4-amino-6-bromo-3-methoxypicolinate (2 g, 7.66 mmol), tributyl(1-ethoxyvinyl)stannane (4.15 g, 11.49 mmol) and bis(triphenylphosphine)palladium(ii) chloride (0.807 g, 1.149 mmol) in DCE (19.15 ml) were stirred under microwave irradiation (120° C., 30 min). The reaction was not completed (LC). Additional tin reagent (1 equiv) and palladium catalyst (0.15 equiv) were added and the reaction mixture was stirred under microwave irradiation (120° C., 30 min). The mixture was adsorbed onto celite and purified by flash column chromatography (ISCO, SiO2 80 g, hexane/EtOAc 100:0 to 0:100 gradient) to afford methyl 4-amino-6-(1-ethoxyvinyl)-3-methoxypicolinate (1.68 g, 6.66 mmol, 87% yield) as a yellow solid. Mp 72-73° C.; EIMS m/z 253 ([M+H]+); 1H NMR (400 MHz, CDCl3) δ 7.15 (s, 1H), 5.34 (d, J=2.0 Hz, 1H), 4.45 (s, 2H), 4.31 (d, J=1.9 Hz, 1H), 3.96 (s, 3H), 3.92 (q, J=7 Hz, 2H), 3.86 (s, 3H), 1.41 (t, J=7.0 Hz, 3H).

Workup

custompurified by flash column chromatography (ISCO, SiO2 80 g, hexane/EtOAc 100:0 to 0:100 gradient)

Sources & evidence

ORD record: ord-15ff47e17bcf4825ad90e45a581c23c3
Source dataset: uspto-grants-2014_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08754229B2

Reaction notes

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