Triethylamine → (3R)-3-methyl-4-(1-methyl-6-oxo-1,6-dihydro-[4,4']bipyrimidinyl-2-yl)-piperazine-1-carboxylic acid tert-butyl ester

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Reaction Steps

A solution of 2-chloro-3-methyl-6-(pyrimidin-4-yl)-3H-pyrimidin-4-one (5.3 g, 24 mmol), tert-butyl (3R)-3-methylpiperazine-1-carboxylate (5.0 g, 25 mmol) and triethylamine (7.6 g, 75 mmol) in N-methyl-2-pyrrolidone (25 ml) was stirred for 6 hours at 90° C. The solution was partitioned between water and ethyl acetate, and the organic layer was washed with water, brine, dried over sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent; ethyl acetate) to afford (3R)-3-methyl-4-(1-methyl-6-oxo-1,6-dihydro-[4,4′]bipyrimidinyl-2-yl)-piperazine-1-carboxylic acid tert-butyl ester (6.9 g, 71%).

Provenance & Evidence