Lithium Hydroxide → 5-Bromo-6-(4-chloro-phenyl)-3-trifluoromethyl-pyrazine-2-carboxylic acid

Participants

Reaction Steps

To a solution of 7.7 g 5-bromo-6-(4-chloro-phenyl)-3-trifluoromethyl-pyrazine-2-carboxylic acid methyl ester in 50 ml tetrahydrofuran was added at 0° C. 20 ml of a 1M solution of lithium hydroxide in water. The cooling bath was removed and the mixture was stirred at ambient temperature for 20 min. The orange reaction mixture was partitioned between heptane and water. The phases were separated the aqueous phase was mixed with ethyl acetate and 10% aqueous citric acid whereby the yellow orange color almost disappeared. The phases were separated and the organic phase was washed with brine dried over sodium sulfate, evaporated and dried under high vacuum to yield 5.54 g of the title compound as yellow solid. This material was recrystallized from ethyl acetate/heptane before use. MS (M−H) at 381.1 and 379.1.

Provenance & Evidence