Potassium Carbonate → 2,2-Dimethyl-5-[2,3,5-trimethyl-4-(phenylmethoxy) phenoxy]pentanoic acid, methyl ester

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Reaction Steps

A 2-1, 3 neck, round bottom flask equipped with an overhead stirrer is charged with 29.4 g (12mmol) of 2,3,5-trimethyl-4-(phenylmethoxy)phenol (Example C), 29.8 g (1.1×12.1 mmol) of 5-bromo-2,2-dimethylvaleric acid, methyl ester (U.S. Pat. No. 4,665,226), 20.1 g (1.2×121 mmol) of anhydrous potassium carbonate and 300 mL of acetonitrile. The heterogeneous mixture is stirred at reflux for 96 hours. The solid is removed and the reaction flask and filtered solids are washed with fresh acetonitrile, the solvent removed and the residue taken up in 500 mL of hexane. On standing the product crystallizes partially and a seed crystal is retained. The solution is diluted to 700 mL with hexane and warmed to dissolve the product. After washing with 2×75 mL of 2N potassium hydroxide solution, and brine the solution is dried and evaporated leaving 46.5 g of a pale yellow solid. This crystallizes from 500 mL of hexane in the presence of charcoal and the solution is cooled to 0° C. and seeded to afford 41.4 g of the title compound as a colorless solid; mp 67°-68° C.

Provenance & Evidence