Reaktion #2359426

Reaktionsgleichung

5-bromo-2-fluoro-6-methyl-benzofuran

2-aminopyrazine-5-boronic acid pinacol ester

K3PO4

EA

→

5-(2-fluoro-6-methylbenzo[b]furan-5-yl)-pyrazine-2-ylamine

Ausbeute 25.4%

Lösungsmittel

ACN

dioxane

H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas bubbled with argon
2. 2
   TemperaturAfter cooling down to r.t.
3. 3
   Waschenwashed with aq. NaHCO3 and brine
4. 4
   Trocknenphase was dried over Na2SO4
5. 5
   Einengenconcentrated

Vorschrift

A mixture of 5-bromo-2-fluoro-6-methyl-benzofuran (230) (0.3 mmol), 2-aminopyrazine-5-boronic acid pinacol ester (133 mg, 2 eq), bis(ditertbutyl(4-dimethylaminophenyl)phosphine)dichloropalladium (II) (42 mg, 10% mol) and K3PO4 (127 mg, 0.6 mmol) in 1 ml ACN, 1 ml dioxane, 0.5 ml H2O was bubbled with argon before heated at 85° C. for 2 h. After cooling down to r.t., the reaction mixture was taken up in EA, washed with aq. NaHCO3 and brine. Org. phase was dried over Na2SO4, concentrated and then subjected to silica gel flash column chromatography (0-100% B, A: hexane; B: EA) to give 5-(2-fluoro-6-methylbenzo[b]furan-5-yl)-pyrazine-2-ylamine (234) (18.5 mg, purity>95%, yield: 25.4%) as yellow solid.

Quelle