Hydrochloric Acid → HCID 67042919, compound

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Reaction Conditions

Reaction Steps

32.0 g (106 mmol) of 4′-benzyloxy-2,3-difluorobiphenyl (CAS No. 305366-70-5) are dissolved in 250 ml of THF, and 75.0 ml (119 mmol) of a 15% solution of n-butyllithium in hexane are added dropwise at −70° C. When the addition is complete, the mixture is stirred for a further 1 h, and a solution of 13.5 ml (119 mmol) of trimethyl borate in 50 ml of THF is added dropwise. After 1 h, the batch is left to thaw, MTB ether is added, and the mixture is acidified using 2 M hydrochloric acid. The org. phase is separated off, washed with sat. sodium chloride solution and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is heated to 70° C. in 200 ml of heptane/toluene (1:1) with stirring and filtered off with suction after cooling, giving 4′-benzyloxy-2,3-difluorobiphenyl-4-boronic acid as a colourless solid, which is employed in the next step without further purification.

Provenance & Evidence