反应详情

1.96 g (6.62 mmol) of the above synthesized 2-methyl-6-(3-trifluoromethyl-phenyl)-nicotinic acid methyl ester in 14 ml of abs. THF was cooled down to 0° C. and reacted with 13.8 ml of DIBAL-H-solution (1.2 M in toluene, 2.5 eq.) for 1 h. Careful quenching with ice/NH4Cl, twofold extraction with AcOEt, washing with brine, drying over sodium sulfate, and evaporation of the solvents left a crude product which was purified by flash chromatography (SiO2, hexane/AcOEt=55/45) to deliver finally 1.66 g of the title compound as white crystals of mp. 75-77° C.

1. customCareful quenching with ice/NH4Cl, twofold extraction with AcOEt
2. washwashing with brine
3. dry with materialdrying over sodium sulfate, and evaporation of the solvents
4. waitleft a crude product which
5. customwas purified by flash chromatography (SiO2, hexane/AcOEt=55/45)