1-Phenyl-1,2-propanedione → 3-Bromo-1-phenylpropane-1,2-dione

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Reaction Steps

To a solution of 1-phenyl-propane-1,2-dione (1.72 g, 0.0116 mol) in DCE (5 mL) was added Br2 (1.87 g, 0.0169 mol). The reaction mixture was stirred for 75 min. and the volatiles were removed to yield 3.21 g of 3-bromo-1-phenyl-propane-1,2-dione. The crude bromoketone (0.1046 mol) was combined at room temperature with 3-(1-cyclopentyl-thioureido)-propionic acid tert-butyl ester (7.00 g, 0.031 mol) in NMP (50 mL) following general procedure B. The reaction was purified by silica gel chromatography (gradient, hexane→8% EtOAc-hexane) to yield 3-[(4-Benzoyl-thiazol-2-yl)-cyclopentyl-amino]-propionic acid tert-butyl ester (4.0 g).

Provenance & Evidence