Dimethylformamide → Tert-butyl 5-(pyrazin-2-yl)picolinate

HRID 711247Notes

Reaction equation

Br[C:2]1[CH:3]=[CH:4][C:5]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])=[N:6][CH:7]=1.C([Sn](CCCC)(CCCC)[C:20]1[CH:25]=[N:24][CH:23]=[CH:22][N:21]=1)CCC.CN(C=O)C>C(OCC)(=O)C.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[N:21]1[CH:22]=[CH:23][N:24]=[CH:25][C:20]=1[C:2]1[CH:3]=[CH:4][C:5]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])=[N:6][CH:7]=1

Participants

Conditions

Temperature: 120 °C

Procedure

To a flask containing tert-butyl 5-bromopicolinate 41-1 (1.55 g, 6.0 mmol), 2-(tributylstannyl)pyrazine 41-2 (2.21 g, 6.0 mmol) and Pd(PPh3)4 (426 mg, 0.6 mmol) under argon was added DMF (15 mL). The mixture was stirred at 120° C. for 10 hours. After cooling to room temperature, the mixture was diluted with ethyl acetate, washed with H2O and brine, dried over Na2SO4, and concentrated to dryness by rotary evaporation. The crude product was purified by silica gel flash chromatography, eluted with 5% methanol in dichloromethane to give tert-butyl 5-(pyrazin-2-yl)picolinate 41-3 as a pale yellow solid. MS m/z 258.1 (M+1)

Workup

temperatureAfter cooling to room temperature
washwashed with H2O and brine
dry with materialdried over Na2SO4
concentrationconcentrated to dryness by rotary evaporation
customThe crude product was purified by silica gel flash chromatography
washeluted with 5% methanol in dichloromethane

Sources & evidence

ORD record: ord-a6901f828e26430c8777c88897947084
Source dataset: uspto-grants-2015_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09181235B2

Reaction notes

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