Triethylamine → (S)-4-(5-Methoxycarbonyl-4-trifluoromethyl-pyrimidin-2-yl)-piperazine-1,3-dicarboxylic acid 1-tert-butyl ester 3-methyl-ester

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Reaction Steps

Combine 2-Chloro-4-trifluoromethyl-pyrimidine-5-carboxylic acid methyl ester (240 mg, 1.70 mmol), (S)-piperazine-1,3-dicarboxylic acid 1-tert-butyl ester 3-methyl ester (2.04 mmol) and triethylamine (5.11 mmol) in a 0.85 M solution of dioxane. Microwave reaction mixture for 30 min at 150° C. Filter reaction mixture and rinse with acetonitrile. Purify filtrate by column chromatography in a 0-70% ethyl acetate/heptane gradient to give (S)-4-(5-Methoxycarbonyl-4-trifluoromethyl-pyrimidin-2-yl)-piperazine-1,3-dicarboxylic acid 1-tert-butyl ester 3-methyl-ester contaminated with approximately 15% of the mono hydrolysis product. The mixture is carried on to next step without further purification. (61% yield)

Provenance & Evidence