Potassium Phosphate, Tribasic → Methyl [4-(3-cyclopropylpyrazin-2-yl)phenyl]acetate

Participants

Reaction Steps

To a solution of 0.15 g (0.57 mmol) of methyl [4-(3-chloropyrazin-2-yl)phenyl]acetate acid in 3.0 mL of toluene and 0.15 mL of water were added 63.8 mg (0.74 mmol) of cyclopropyl boronic acid, 16 mg (0.06 mmol) of tricyclohexylphosphine, 7.8 mg (0.009 mmol) of Pd2(dba)3, and 0.42 g (2.0 mmol) of potassium phosphate. The resulting suspension was degassed for 10 minutes. After 1 h in the microwave at 140° C., the reaction mixture was cooled, diluted with CH2Cl2, wash three times with water, and washed with brine. The organic layer was dried over Na2SO4, filtered and concentrated in vacuo. Purification by flash chromatography (silica gel, linear gradient 0-40% EtOAc in hexanes) afforded 0.10 g (65%) methyl [4-(3-cyclopropylpyrazin-2-yl)phenyl]acetate. 1H NMR (CDCl3, 400 MHz) δ 8.35 (m, 2H); 7.68 (d, J=8.06 Hz, 2H); 7.41 (d, J=8.06 Hz, 2H); 3.72 (s, 3H); 3.71 (s, 2H); 2.22 (m, 1H); 1.19 (m, 2H); 0.99 (m, 2H). ES-MS M+1=269.1.

Provenance & Evidence