Felbinac → alpha-Methyl(1,1'-biphenyl)-4-acetic acid

Beteiligte Stoffe

Reaktionsschritte

In usual manner, lithium diisopropylamide in tetrahydrofuran was prepared with diisopropylamine (3.2 ml, 22.6 mmol) and 1.6M n-butyllithium in hexane (14.2 ml, 22.6 mmol). ("Reagents for Organic Synthesis", 2, p. 249) To this lithium diisopropylamide in tetrahydrofuran was added dropwise 4-biphenylyl acetic acid (2.40 g, 11.3 mmol) in tetrahydrofuran at from -50° C. to -30° C. After the mixture was reacted at from -40° C. to -10° C. for 2 h, to the mixture was added dropwise methyliodide (1.77 g, 12.4 mmol) in tetrahydrofuran, then the temperature was rised at from -30° C. to room temperature in nature. After the mixture was stirred for 4 h, was added water and was adjusted at pH 2 with 3N sulfonic acid, then extracted with ether. After the ether extract was dried over, then the extract was evaporated under reduced pressure to a residue, which was chromatographed to afford 2-(4-biphenylyl)propionic acid (2.38 g, 93% yield) as white crystalline material: mp 144°-145° C.

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