Potassium Phosphate, Tribasic → 2-(4-(Pyrazin-2-yl)phenyl)acetic acid

Participants

Reaction Steps

To a solution of 0.40 g (1.53 mmol) of [4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]acetic acid in 4.0 ml of dioxane was added 0.18 mL (1.73 mmol) of 2-iodopyrazine, 10.3 mg (0.037 mmol) of tricyclohexylphosphine, 13.9 mg (0.015 mmol) of Pd2(dba)3, and 2.0 ml (1.27 M, 2.59 mmol) of aqueous potassium phosphate solution. The resulting suspension was degassed for 10 mins. After 30 min in the microwave at 150° C., the reaction mixture was cooled, acidified with 1N HCl, extracted with ethyl acetate, and washed with brine. The organic layer was dried over Na2SO4, filtered and concentrated in vacuo. Purification by preparative HPLC (5->95% CH3CN/H2O over 15 min, 0.05% added TFA, C18) afforded 0.10 g (32%) of (4-pyrazin-2-ylphenyl)acetic acid. 1H NMR (CD3OD, 400 MHz) 9.1 (s, 1H); 8.66 (t, J=1.74 Hz, 1H); 8.51 (d, J=2.57 Hz, 1H); 8.04 (d, J=8.15 Hz, 2H); 7.46 (d, J=8.15 Hz, 2H); 3.70 (s, 2H). ES-MS M+1=215.1.

Provenance & Evidence