4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole → (4-{4-[4-(1H-pyrazol-4-yl)-phenyl]-piperidin-4-yl}-phenoxy)-acetic acid

Participants

Reaction Conditions

Reaction Steps

{4-[4-(4-bromo-phenyl)-piperidin-4-yl]-phenoxy}-acetic acid ethyl ester was reacted with 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole following the procedure set out in Example 1, but using tetrakis(triphenylphosphine)palladium (0) as the catalyst and heating at 80° C. for 30 minutes, to yield a mixture of the title compounds. On work up the basic aqueous extract was neutralised with hydrochloric acid and extracted with ethyl acetate (×2), then these organic extracts were combined and washed with brine, dried (MgSO4), filtered and concentrated to give a crude product that was recrystallised from water to afford (4-{4-[4-(1H-pyrazol-4-yl)-phenyl]-piperidin-4-yl}-phenoxy)-acetic acid (12 mg, 5%); LCMS (PS-A3) Rt 5.33 min [M+H]+ 378. 1H NMR (DMSO-d6) δ 2.22-2.26 (4H, m), 2.67-2.71 (4H, m), 4.65 (2H, s) 6.67 (2H, d), 7.11 (2H, d), 7.24 (2H, d), 7.46 (2H, d), 7.96 (2H, br.s).

Provenance & Evidence