2,4,6-Trimethylpyridine → 3-Benzylsulfonylamino-6-methyl-1-(tert-butoxycarbonylmethyl)-2-pyridinone

Participants

Reaction Conditions

Reaction Steps

Collidine (0.59 mL, 4.5 mmole) was added in one portion to a stirred solution of the compound of Example 94 (0.89 g, 3.7 mmole) and benzylsulfonyl chloride (0.86 g, 4.5 mmole) in acetonitrile (20 ml) cooled in an ice bath. The solution was stirred for 5 minutes at 0° C., followed by 45 min at room temperature. The reaction mixture was quenched with water, then diluted with ethyl acetate (100 mL), washed with 3% HCl (until aqueous layer is pH 1), and brine, dried over magnesium sulfate, and the solvent was removed. The residue was dissolved in methanol, concentrated to a volume of approximately 3 mL, and the product was precipitated with the addition of diethyl ether. The precipitate was filtered to give 0.67 g of the title compound. The filtrate was concentrated and chromatographed on flash silica gel using 20-67% ethyl acetate hexanes as eluent. An additional 0.20 g of the title compound was recovered. A total of 0.87 g of the title compound (59% yield) was recovered. Rf=0.29 (silica gel, 33% ethyl acetate/hexanes).

Provenance & Evidence