Nitrogen → 6-Methyl-2,3-di-p-tolyl-5H-pyrrolo[2,3-b]pyrazine

Participants

Reaction Steps

2-Bromo-3-chloro-6-methyl-5H-pyrrolo[2,3-b]pyrazine (step 3) (183 mg, 0.742 mmol) in dioxane (5 ml) was degassed with N2 and treated with p-tolylboronic acid (242 mg, 1.782 mmol), K2CO3 (308 mg, 2.227 mmol) and PdCl2(dppf)-CH2Cl2-adduct (60.6 mg, 0.074 mmol). The reaction mixture was heated at reflux for 3 hours. After cooling to RT, further portions of p-tolyl boronic acid (242 mg, 1.782 mmol) and PdCl2(dppf)-CH2Cl2-adduct (60.6 mg, 0.074 mmol) were added and heating continued at reflux for 2 hours. After cooling to RT, the mixture was diluted with water (50 ml). The resultant suspension was sonicated and filtered, rinsing the filter cake with water (×3). Purification of the crude product by chromatography on silica eluting with 0-30% EtOAc in iso-hexane afforded the titled compound;

Provenance & Evidence