2(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl- → 1,2,3,4-Tetrahydro-6-[hydroxy(1-phenyl-1H-pyrazol-4-yl)methyl]-3-methyl-1-(1-methylethyl)-2,4-dioxo-thieno[2,3-d]pyrimidine-5-carboxylic acid ethyl ester

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Reaction Steps

To a solution of 1,2,3,4-tetrahydro-3-methyl-1-(1-methylethyl)-2,4-dioxothieno[2,3-d]pyrimidine-5-carboxylic acid ethyl ester (2.0 g), 1-phenyl-1H-pyrazole-4-carboxaldehyde (1.39 g) and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (1.63 ml) in anhydrous THF (35 ml) was added a 2.0M solution of LDA (3.72 ml) at −78° C. under nitrogen and the resulting mixture stirred for 3 hr. Glacial acetic acid (1.5 ml) was added, the mixture allowed to warm to room temperature, diluted with water and extracted with ethyl acetate, the organic extracts washed with water, dried over anhydrous magnesium sulfate, filtered and evaporated under reduced pressure. The residue was purified by column chromatography over silica, eluting with i-hexane/ethyl acetate (4:1) followed by i-hexane/ethyl acetate (1:1) to give the sub-title compound (2.32 g).

Provenance & Evidence