(R)-3,3-Dimethyl-2-aminobutane → (R)-3-(2-hydroxy-6-methylphenylamino)-4-(2,2,1-trimethylpropyl-amino)-cyclobut-3-ene-1,2-dione

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Reaction Steps

3-Ethoxy-4-(2-hydroxy-6-methyl-phenylamino)-cyclobut-3-ene-1,2-dione (0.4 g, 1.62 mmol) and (R)-2-amino-3,3-dimethylbutane (16 mL of a 0.2M solution in absolute ethanol, 3.20 mmol) in dichloromethane (4 mL) was heated at 80° C. for 4 hours. The reaction mixture was cooled, concentrated under reduced pressure, and the resulting residue was trituated with hexane:ethyl acetate (1:1) to produce a solid, which was filtered and rinsed with hexane:ethyl acetate (1:1). Chromatography with 10% methanol in dichloromethane gave (R)-3-(2-hydroxy-6-methylphenylamino)-4-(2,2,1-trimethylpropyl-amino)-cyclobut-3-ene-1,2-dione, 0.24 g (0.79 mmol, 49%).

Provenance & Evidence