Hydrochloric Acid → 2-Methyl-5-(5-methyl-1,3,4-oxadiazol-2-yl)phenylboronic acid

Participants

Reaction Conditions

Reaction Steps

Isopropylmagnesium chloride (2.0 M in tetrahydrofuran, 10 mL, 20.0 mmol) was added dropwise over 20 minutes to a stirred solution of 2-(3-Iodo-4-methylphenyl)-5-methyl-1,3,4-oxadiazole (preparation 55c, 4.0 g, 13.3 mmol) in tetrahydrofuran (40 mL) at −10° C. The mixture was stirred for 1 hour at −10° C. then triisopropyl borate (4.71 mL, 20.0 mmol) was added dropwise over 10 minutes and the mixture was stirred for 1 hour at −10° C. Then, the mixture was warmed to room temperature and stirred overnight. Water was then added, the mixture was cooled by means of an ice-water bath and the pH was adjusted to 3-4 with 2M aqueous hydrochloric acid. The mixture was extracted with ethyl acetate and the organic layer was washed with brine, dried (MgSO4) and evaporated. The residue was triturated with diethyl ether and the solid was filtered and dried to give the title compound (1.92 g, 66%) as a white solid.

Provenance & Evidence