Methyl iodide → 7-methanesulfonyl-1-methyl-3-(2-methyl-5-nitro-phenyl)-3,4-dihydro-1H-pyrimido[4,5-d]pyrimidin-2-one

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Reaction Steps

To the suspension of NaH (60% dispersion in mineral oil, 139 mg, 3.5 mmol) in DMF is added 7-methanesulfonyl-3-(2-methyl-5-nitro-phenyl)-3,4-dihydro-1H-pyrimido[4,5-d]pyrimidin-2-one (1.15 g, 3.2 mmol), prepared as in Reference 1, at 0° C. When H2 evolution has ceased, iodomethane (0.99 ml, 15.8 mmol) is added and the reaction mixture is stirred for 3 hours at room temperature. The mixture is diluted with ethyl acetate, and washed with 5% aqueous Na2S2O3 solution to remove DMF. The organic layer is dried over MgSO4 and concentrated under reduced pressure. The crude product is purified by flash column chromatography (SiO2, EtOAc/hexane=1/1) to give 7-methanesulfonyl-1-methyl-3-(2-methyl-5-nitro-phenyl)-3,4-dihydro-1H-pyrimido[4,5-d]pyrimidin-2-one (0.85 g, 70%) as a white solid.

Provenance & Evidence