Methanol → 4'-[3-[Hydroxyimino]-3-(2-methyl-pyridin-4-yl)-1-o-tolyl-propyl]-biphenyl-4-carboxylic acid

Participants

Reaction Steps

To a solution of 4′-[3-[hydroxyimino]-3-(2-methyl-pyridin-4-yl)-1-o-tolyl-propyl]-biphenyl-4-carboxylic acid methyl ester (352 mg) in THF (7.5 mL) was added a drop of methanol and a 1 M aqueous lithium hydroxide solution (7.6 mL) at 0° C. The reaction mixture was stirred at rt for 2 hours. A 1M aqueous solution of KHSO4 (7.5 mL) was added, the phases were separated and an extraction was made with EtOAc and a saturated solution of NH4Cl. The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The crude product was purified by flash chromatography on silica gel (CH2Cl2/MeOH 9:1) to yield 4′-[3-[hydroxyimino]-3-(2-methyl-pyridin-4-yl)-1-o-tolyl-propyl]-biphenyl-4-carboxylic acid as a mixture of E and Z isomers (3:1) as a white foam (288 mg, 84%), MS (ESI−): m/z=449.2 ([M−H]−).

Provenance & Evidence