1,2,3-Trifluorobenzene → HCID 18985427, compound

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Reaction Steps

Thus, 1-triisopropyloxytitanyl, 3,4,5-trifluorobenzene--prepared by transmetalation of 3,4,5-trifluorobenzenemagnesiumbromide using chlorotriisopropyloxytitanium--is reacted chemoselectively with ethyl cyclohexanone-4-carboxylate (1) on the carbonyl group to give ethyl 4-hydroxy-4(3,4,5-trifluorophenyl)cyclohexanecarboxylate. Elimination of water, catalytic hydrogenation over Pd/C, hydrolysis and epimerization using KOH/methanol give the pure trans 4-(3,4,5-trifluorophenyl)cyclohexanecarboxylic acid-(1). The latter is converted into the mixed anhydride using pivaloyl chloride and, using N,O-dimethylhydroxylamine, into the corresponding amide. The latter is reduced in high yield using LiAlH4 to give the aldehyde IIIa'.

Provenance & Evidence